Hi OFC/BFLG Family!

Hope all of you are doing well. It has been a long long time since I've had the chance to check out the OFC, much less post anything. Like many of you, I've been experiencing so many changes over the past year! Fortunately, haven't had to battle COVID myself (yet - fingers crossed); but aging parents, early retirement, moving homes and ensuing carpentry necessities have really kept me running for quite some time. Frankly, I don't know if I'll ever get to the end of this project either, but a bit of breathing space today prompted me to sit in front of my laptop to start this thread about a 1115-1 Pacemaker that I had the fortune of acquiring recently...

With Detlef and TwoWheel going on and on about their twelve strings, I just couldn't pass this up and it's a 12-Fretter to boot! These never come up for sale over here, but I made an offer for roughly $250 bucks (which I never thought would cut it), but here it is. This 1115 has some issues. There are two top cracks that are so common on these older Os (pretty long and go through the wood) that need to be cleated.

The bigger issue is going to be the headstock truss rod adjustment nut. Instead of the 1/4 inch nut stripping the threads on the rod, this nut kept screwing in until the wood area under the string-nut collapsed.

The collapse wood created a steep angle and as the adjustment nut was tightened, the truss rod end began to bend upward. Inside the headstock end of the neck, the bent truss rod began to exert force on the neck behind the string-nut weakening the headstock area of the neck - fortunately the headstock is still holding together.

So, the top will need to be humidified and cleated like seesquare did in his Pandora II thread. The "Vintage 12 String / Truss Rod is Not Hex" thread also showed me what a healthy 1115 truss rod adjustment area looked like enabling me to identify what was happening with this guitar's rod. Need to find a way to bend the truss rod back to the correct angle and rebuild the truss rod adjustment cavity as well as reinforce the underside of the string-nut area of the neck. Don't know how far I'll get, but it's not going anywhere if I don't start so... here we go! Wish me luck.

Thanks for the encouragement seesquare and MWoody - I really missed hanging out here!

I get what you mean about not being able to tune to concert pitch. I'll try not get my expectations up too high!

So moving forward a bit. Per the Ovation Tribute website's "Ovation Bracing" page here, this guitar has the "Ovation Fan" bracing.

At some point, loose braces were glued down using CA glue, and they are firmly in place. So no need to glue down any loose braces here. The center crack goes down to the middle V area so one of the cleats will need to be shaped to fill the V up to the bridge plate. First, I'll need to humidify the top to close-up the cracks.

The entire guitar is terribly dry including the ebony fretboard which is slightly cracked near the sound hole. Gonna use a small round plastic tray with a folded cloth in it (to keep the water from spilling inside the bowl), cover the cracks with plastic sheets, and cover the entire guitar with bubble wrap (to keep the humidity contained) and leave her over night. The water is heated and cooled back down to 75 degrees C (about 170F) and poured into the tray over the towel then placed in the sound hole and positioned under the severest cracked area. If there is too much water or the water is too hot, condensation could occur under the sound board causing water build up and over expansion which in turn will strain the braces or the kerfing so starting very conservatively.

Okay... that's about it for now. Gonna start cutting and carving up the cleats. Planning on making the cleats out of some Pacific Redwood scraps from one of my nylon string re-top projects from yesteryear. Haven't had this much fun in a long long time! Thanks for letting me share on the BFLG!

I had a similar tr problem with a 12 string, the screw was too tight and the wood was collapsed behind the saddle. First I removed the screw, and fixed the broken wood. After that I replaced a part of the neck wood with solid ebony, added a metal plate and a metal washer and thus was able to work with the tr. again.

Maybe you could try a similar solution, but I´m afraid you have to go maybe until under the fretboard.

@LOF - Thanks Al! It's great to be back. Thanks for your thoughts and your encouragement!

@Detlef - the 12-string Maestro has spoken! Thanks for the great info and pics! Did you just CA glue the carbon fiber into place? Definitely will need to carve the wood up to just about a mm under the fretboard. Thinking that's going to be the most difficult part of this project. Planning on using some birch, but I do have some carbon fiber blanks too. Did you just super glue the carbon fiber into position? I was planning on using a bit of left over hysol for adhesion. Thanks for sharing! It's good to know this battle can be won!

By the way, this is my Fxxxxr F330. It's an MIJ all laminate 12-string. Sounded amazing and was my main guitar for about 10 years. Practically used it every week; so, I kept it at concert pitch. One day it refused to stay in-tune as I was playing, and after a few frustrating attempts to keep it in-tune, I realized the neck was beginning to come apart from the body. Removed the strings, and the neck just popped right out of the dove joint. Pretty sure hide glue was used and the glue joint just gave out. It's been disassembled since and is awaiting a new spruce or cedar top. Don't imagine this would ever happen to an Adamas, but anything less...I don't know...

Anyway...hope to finish the easier part of the project today, and get to the truss rod cavity thereafter. Thanks for all the great advice everybody! Be back in a bit!

Completed the hydration process by soaking the towel in the round hydration tray twice. The hydration process went very well. Both top cracks are completely back to proper dimensions so all I have to do is glue the cleats in place. Shaped some old low grade Pacific Redwood scraps into cleats. Redwood is very flexible with the grain, but very stiff perpendicular to the grain, and is very very light. They'll provide good support without overly compromising the resonance of the sound board. Here's my cleating plan.

Did a couple of dry runs, and decided to just use Titebond to glue in the cleats.

Worked one cleat at a time by applying the adhesive into the crack from inside the bowl and lightly pushed the cracked area from the outside over and over to let the glue work a little bit into the crack. The straight center cleats were clamped lightly. The V cleat fit snuggly so I just flipped the guitar bowl-side up and put a weight on it while the glue dried. Magnets were used to apply the cleat on the side crack.

Dan always warns against "creeping" when using Titebond, and that's exactly what happened with the side cleat that I clamped with magnets. By the time the glue cured the cleat moved ever so slightly requiring an additional cleat to be applied to the area. No big deal, but I think I could have prevented the creeping by just applying some masking tape over the magnet inside the bowl, doh!

In any case, I'll finish the top by applying CA glue to the cracks in the finish and the cracked rosette, scrape and sand the CA glue and re-buff the entire top. But first, I'll need to start work on the truss rod adjustment area of the neck. Fortunately, the neck angle looks good meaning that I won't have to venture into "bowl bending" territory!

Unfortunately, the nut is stuck in there really tight. The usual truss rod wrench is not working, and pliers aren't cutting it either. Need to think about this a bit more before I plunge forward! That must mean it's a good time to stop. Be back in a bit!

Thanks seesquare and OMA!
Yes, Stewmac does make a tool to recut the truss rod cavity; but like you say, it is used after the nut is removed. Really useful tool that's used when the truss rod end either breaks or the threads become stripped. The tool cuts a deeper truss rod cavity, and another tool is used to re-thread the end of the stripped or broken truss rod. The tool makes broken truss rods much easier to repair, but a poor cut of the truss rod cavity weakens that whole area of the neck significantly.

Meanwhile, wanted to get in as much work as I can while I can so decided to get back to removing the truss rod adjustment nut. Man am I glad that O used a 1/4" hex nut back in the day. Quarter inch is the international standard for hex sockets even in Japan. After rummaging through some of my old tools I found this manual screw driver socket wrench!

Cool - perfect fit! After chiseling around the nut and embedded TR washer a bit, got a perfect fit and the nut was off. Got my super thin cutting knife to pry the washer loose and voila!

Grabbed a blank piece of wood to see if I can get the truss rod bent back to the proper position - don't push too hard - easy does it, easy does it - and voila!

Cleaned up the mushed-up maple a bit...

Hmmm...

Now how am I going to rebuild this area? Definitely gonna need more time to think...

Better switch gears and fill the top finish cracks with CA glue! Used some high viscosity CA and applied the glue directly onto the finish of the sound board. Gently pushing and releasing the sound board under the cracks to get the glue to work into the finish. The glue seeps into the cracked finish and leaves a bit of a valley, so I keep filling the gaps with glue until all the valleys become mounds. Once the glue is dry, the mounds of CA glue will be scraped level to the finish with an exacto knife blade. The entire top will be sanded and buffed or re-shot with a thin coat of clear poly finish and buffed. The cracks won't be invisible, but the process will discourage the existing finish cracks from extending further.

The last thing before "calling it a day" was applying lemon oil to the bone dry ebony fingerboard. Now, if the truss rod cavity can be fixed properly, this is going to be a beautiful instrument! Better sleep-on-it for now...

Hey Al! Thanks for the interest. Will send an update on my family by e-mail soon...

With regard to the hydration: I had to repeat the process just once. The towel was wetted with warm water and wrung out and placed into the tray. By estimation, I poured about 50ml of hot water in the tray each time over the wet but wrung out towel. The 2nd 50ml went in when the standing water in the tray was gone. At that point, the cracks were still not fully healed.

With regard to the Redwood cleats: yeah, grain perpendicular to the cracks. You might remember the Redwood top I used for my heirloom rebuild. I used left over scraps from this top...

This piece of lumber is "low" grade because the grains are not tight like the more sought after stuff that you'll see on Patch's beautiful Redwood O's (but I really love the look and color match with this nylon stringer's maple b/s and neck). That's probably why the grains are not visible to you, but they are there. Also, I wanted cleats that were a bit thicker to withstand the tendency for the top to return to its pre-cleated condition. When I sent my friends Nakao NNS778-9 Elite with a cracked top to the Mother Ship back in 2015, Mr. Budny and gang used some pretty hefty square shaped spruce cleats to make the repair. Thought I'd better not veer to far from what they did. Sorry for rambling on my friend!

I didn't realize 12-string tuning was such a controversial issue, DetlefMichel! Lol!

Thanks FlySig! Been itching to get back!

Was able to make a little progress on the easier top cracks. The CA glue dried up nicely so I went ahead and scraped the mounds of CA flat. To minimize the possibility of gouging the finish, I use a small piece of an exacto knife and push lightly with the middle of the blade into a convex shape.

The cracks in the finish will still be visible after polishing the finish back to luster, but the cracks have been stabilized, and the top is finished! Now, how am I going to tackle the truss rod adjustment area?

After some thought, decided I needed to make a mock-up truss-rod adjustment cleat out of Birch and test if the truss rod is actually working! Would be tragic to fix everything only to find the rod doesn't work at all! The collapsed area behind the truss rod nut is angled to about 20 degrees to the fret board. The truss rod should be about 10 degrees so, my mock up needs to compensate accordingly.

Really like working with Birch, but the final filler is going to be made of African Black Wood which is considerably harder than Ebony.

I'll drill a hole in the mock up tomorrow, string up the guitar with six strings only, apply some washers and tighten the truss rod nut to see if the relief is eliminated. If it's all on the up-and-up, I'll start working on repairing the truss rod adjustment area. African Black Wood is super hard and brittle so it'll take more time than the Birch mock-up, but just making progress through the project feels good!

Thanks TPA and Twowheeldrummer. So glad to be working on guitars again! Getting to share my progress here is such a privilege! Thanks for commenting!

@Twowheel - Yes, I've seen that video and use Dan Erlewine's techniques a lot. He's an enriching resource for sure. For this particular project, the cracks are fairly extensive so I'm planning on sanding down and buffing the entire top. I'm also hoping to thin down the poly finish as they are very thick. Might need to airbrush a thin coat or three of water-based poly before buffing the entire top. Since I'll be rebuffing the whole top a few (or even a lot of) scratches from the exacto knife is not going to be a problem. For what it's worth, I do shorten the exacto blade to minimize any gouging damage that my enthusiastic scrapping might cause.

Continued to make a bit of progress today with the truss rod. A 5mm hole was drilled into my Birch mock-up to make room for the end of the truss rod.

In order to ensure a good tight fit I folded some 120 grit sand paper into the truss rod nut slot, and used that as a guide to sand the mock-up into ideal shape.

Also cut around the truss rod cavity under where the nut goes.

Everything fit nicely. The truss rod angle is good so it was time to add the washer and nut. Added two additional washers to ensure I had plenty of threads to tighten the nut. Let the truss rod test begin!

Since the Birch mock-up is in the way of the D and G strings, I strung up the Ee, Aa, bb, and ee strings. These are EJ39 medium gauge strings so they should provide plenty of tension. A thin piece of Koa was laid on the edge of the fret board where a zero fret might go. Notice that the neck has a lot of relief because the tross rod nut hasn't been tightened.

Tightened the strings just a bit (but not tuned), and began to tighten the truss rod nut little by little. Once the truss rod nut was in a fairly tight and standard depth I verified that the relief in the neck was gone. With the neck flat the 8 strings were tuned to concert pitch. The guitar's top was solid and resonated well. The heel of the head stock was in good shape, but the neck bow was back. At this point, the truss rod nut was turned a quarter turn at a time. After each turn, I verified the top and bridges structural integrity, the headstock heel's integrity and the extent of neck bow. At about the sixth quarter turn, the truss rod end started to bend upward this applied pressure to the headstock heel. From here, I had to apply some pressure to the truss rod end to bend it back down after each quarter turn. When the truss rod was bent down, the headstock heel's pressure was relieved and I could make another quarter turn. Wondering if this means the truss rod is bent or poorly installed - not sure, and I sure don't want to take the fret board off to find out! 

This is how the neck looked after 11 quarter turns. Interestingly, the nut would have gone further.

For this test the string height is irrelevant as I'm using a koa insert as a temporary nut. The important thing is that the neck is straight from both the bass and treble side of the guitar - which means the truss rod is working! The headstock heel is also holding up although for all practical purposes it will have to be reinforced. Now, check out how far the nut screwed into the truss rod.

This is when I noticed the top of my Birch mock-up was gone! It cracked off and flew silently into the abyss. Notice how the Birch mock-up has been compressed. That is some serious pull force this truss rod is generating! My F330 had super low action and was the easiest 12-string to play, but the truss rod wasn't compressing the wood like this! Birch is very similar to maple in hardness and the 5-ply neck used on this O has maple right where the truss rod's nut applies force. But that's a reality for all Os that have 5-ply necks. So what gives? So I loosened the strings and examined my mock-up...

The birch mock-up insert has been completely crushed. Here's how it looked after I removed it from the truss rod cavity.

I've used Birch for some pretty high-load applications in the past, but I've never seen it obliterated like this! Weird! So the good news is the truss rod is working and the headstock heel is holding up...the bad news is; well, there is no real bad news, but I'm thinking African Black Wood may not cut it. May have to resort to carbon fiber??? Whoa, gonna need more time to think!

End of truss rod test!

Took my chisel and thin exacto knife and cleaned around the truss rod. Took Dellef's advice and cleared a relatively straight and flat area upto the fret board.

It was a bit difficult to get at the area behind the fret board, but patience definitely paid off here! Took my mini-file and 120 grit sandpaper and we're good to go!

Now, I just need to decide what material to use as an insert. Carbon fiber, aluminum, Ebony, African Black Wood or something else?

Quite a project you've got going, Ken.

Personally, I would use a bronze bushing.

I've used bronze wheel bushings off R/C cars for bottomed-out TR nuts that needed spacing.

The nice thing about R/C car bushings is that they have a small-ish outer diameter and a large-ish inner diameter. They're also thicker than a washer so you'd only need one.

This allows them to fit over the TR and stay inside the TR cavity in the head stock.

Here's a couple of photos of a sintered bronze bushing I used on a 1617 I re-topped. These particular bushings came from Team Associated and were for their RC10 car. I think these have been discontinued.

I looked on the Team Associated web site and found this bushing set for another car. (Enduro SE)

They don't have any specs, so you'd have to order a set to confirm whether one in the set fits your application.

They also have another set of bushings for their Reflex 14R.

You could also call around to your local hobby stores to see if they have anything that might fit.

Yet another possibility would be R/C airplane wheel collars and for the same reason -- large hole, small outer diameter and thicker than a washer. They are usually nickel-plated brass or stainless steel.

Keep up the good work.

The cut around the truss rod is 1/2 in. (approx. 12mm) in diameter. Since it's been cut flush up to the finger board, my thinking is a 1/2 inch or 12mm anchor would really help spread the load of the truss rod nut over a larger area.  

1). Aluminum shaft coupler:

12mm OD, 5mm/6mm ID, and 20mm L: This will fill the entire truss rod cavity and will need to be hack sawed and ground into shape. Not so sure about adhesion of wood and aluminum.

2). Bronze flange bearing (oil impregnated):

11mm flange OD, 8mm shaft OD, 4mm bore (will need to ream to 5mm). I think this is the stuff Dan was talking about. Thinking a flange would provide better overall stability than a sleeve. Also, the nice thing about a flange bearing is that, I can cut a 1/2 in. OD Ebony dowel, drill a 8mm hole and cover the bearing shaft with some ebony or other wood. This way the flange bearing will be encased in Ebony and will glue into the truss rod cavity more securely. Does that make sense? My only concern was, since it is an oil impregnated bearing, the ebony may weaken over time and crack.

3). Brass flange sleeve bearing (oil-less):

11mm flange OD, 7mm shaft OD, 5mm bore. Same logic as the bronze flange bearing, but this one is not oil impregnated. Might be better than the bronze oil impregnated bearing if I encase the bearing with a wood sleeve.

Ordered all three of the above to test, but thinking one of these will prove to be the Unobtanium! Any thoughts? Will need to wait a week or so for all three to arrive. Meanwhile, I guess I should get started on reinforcing the neck/headstock area. I found out they call this area the "volute" while researching for my reinforcement! Thinkin' it's a good sign that I'm still able to learn...Lol?

Hey OFC/BFLG! Back with some heart break. Yup, in true hack form (just as TPA warned), I broke the truss rod on this beautiful 1115-1. Bummer!

But in hopes that my mistake is not repeated, thought it would be good to leave a record of how I went about attempting the fix... prepare your heart for some guitar carnage ...

Since this truss-rod adjustment exerted unusually high pressure (at least in my estimation), I figured the cavity receiving the washer and nut needed to be as flat as possible so some final prep was performed using a 12 mm dowel with a 5mm bore. Some 60 grit sand paper was double-stick taped to the end.

Just insert the rod and rotate...

Once flatness was satisfactorily achieved needed to select the best flange bearing for the job. The aluminum rod extension cylinder hasn't arrived yet, but these fixtures would be better suited for this project anyway. Bored the bronze flange bearing's (bottom) ID needed from 4mm (L) to 5mm (R). The brass flange bearings (middle) have the right ID, but is a bit long. The larger flange bearing (top) would need to be machined further for a good fit (top) so gonna go with the bronze flange bearing.

Performed some dry runs. Again, recalling to mind the extensive force applied to the truss rod cavity, I decided to add a hard paper plumbing washer (the blue thing) between the wood and the bronze flange bearing in hopes that some of the pressure would be absorbed by the paper washer and spare any wood deformation that might occur (in retrospect, I think this worked very well)...

One final thing was to make sure the string nut fit over the "flange" of the flange bearing. Was originally planning on hacksawing the flange, but decided instead to file the underside of the string nut. Always thought these nuts were bone, but this one was plastic and easy to form.

Then it was time to string her up. Figured this guitar will never wear anything more than extra light gauge strings. DAd's EJ41s are PB and suited to the task. Tightened the truss rod nut to make the neck dead straight, and installed the strings from outside to in.

Once strung, the truss rod nut was tightened as the guitar was tuned to concert pitch. To my surprise the headstock/neck joint was very stable thanks to the truss rod being pulled straight and true. The nut did not seem to be too tight at all and felt easy to turn. Performed a quick set-up and everything was almost perfect. At this point, I was able to verfiy that this guitar sounds magnificent (which bodes well for the future of this guitar)! But then, I thought, "Just one quarter-turn more..." and the heart sinking, "SNAP!" (Warning! guitar carnage ahead...)

After some time, I was able to compose myself and begin the evaluation process (all the time thanking God that this wasn't a friend's guitar!). First thing that jumped out at me was the bronze oil impregnated flange bearing was sweating oil. Took the broken off assembly apart and check this out...

The left is a new bronze flange bearing. On the right is the one I used for this project. Didn't even notice how much this thing was compressing, but I've never seen a truss rod adjustment that could do this to bronze - attesting to my true "hack" status because that just means I was obliviously applying way too much pressure (hence sweating oil)... on the other hand, the neck was still moving as the truss rod was tightened; and IMHO it would have straightened out even more had the truss rod not snapped... 

But the glimpse of this guitar's voice I heard but for a brief moment is enough to keep this guitar in my fold until it is fixed. Thinking there's one more thing I can try with the exposed threads on the truss rod by using one of these female barrel nuts and a sleeve.

With the right length, the barrel nut can thread into the truss rod and pull it while a flanged sleeve can provide leverage, but then this truss rod pulls with some serious force... might just need to install a new truss rod. What to do? What to do?

In any case, here's to hoping that this information might prevent some future BFLG guitar carnage. Thanks for letting me share my journey. Sorry that this one is so anti-climactic, but it will be back - fingers crossed...

Yikes!

That's a real bummer, Ken. Every luthier's worst nightmare. Like you, I would hate it even more if it were someone else's guitar.

As long as there's enough thread on the remaining TR your barrel nut idea might work.

If not, Stewmac does sell tools to perform this type of repair.

See: StewMac Truss Rod Rescue Tools

You could use the relief cutter to deepen the hole around the TR.

As it turns out, they also sell steel spacers in three thicknesses. Who knew?

Worse case scenario would be having to cut new threads on the TR. They sell a die to cut threads, but it's very pricey.

Thanks Seesquare, and thanks for the encouragement everybody! Will be looking for the right fasteners to see if my barrel nut/sleeve idea is do-able over the next couple o-days. Meanwhile...

@Dan - So assuming my barrel nut + sleeve idea doesn't work, do you think it's possible to cut through the neck block to the truss rod end through the sound hole and pull the rod out through the sound hole? I'd rather not remove the fret board to get to the rod if I don't have too, and these older rods require a concave groove to be cut in the neck with a symetrically concave wood cover to ensure the rod stays curved inside the neck. A cut in the middle of the neck block from inside the sound hole might provide enough access to pull the rod out (there's enough rod sticking out of the headstock to lightly pound it out too), and the hole created in the neck block can be filled (it might not even need to be filled). Seems over all structural integrity won't be compromised? In either case, some welding/threading will be necessary to make an appropriate replacement truss rod (I'm sure nobody sells anything like this anymore!). Your expert advice/thoughts would be highly appreciated - please!

Thanks again for chiming in everybody!

As in opening here:

by removing wood ?

You'll notice in the video that he cuts a pretty lengthy thread at the end of the truss rod. A lot of it is cut off in the final adjustment, but there's usually some extra thread on the rod that is hidden under the TR cavity. That's what I'm hoping for with this 1115. If there is more thread hidden in the TR cavity, that will give my barrel nut enough to grab onto.

Oh, and like a big dummy I missed the most obvious and most important dimension that differentiates a 10-32 nut from an M5! It's the diameter! Duh! So the feeling that an M5 nut was a bit loose on a 10-32 bolt was not my imagination! An M5 bolt has a 5mm diameter while a 10-32 has a 3/16 in. (4.76 mm) diameter. That means my M5 barrel nut will fit over the 10-32 truss rod threads with a bit of play and may not be snug enough for this application... not sure how I'm going to find a 10-32 barrel nut in Japan. Everything is metric over here! Gotta spend more time researching! Perseverance shall win the day! Well, one of these days - eventually...

pictured below with the broken end of the truss rod.

Interestingly enough I performed the dry-run using this half-inch barrel nut. The dry run verified that the contemplated method was sound; but the barrel nut had to be tightened like I've never tightened a truss rod nut before! A regular minus head screw driver was just not cut-out for this application. Had to use a socket set with a special head to tighten and remove the barrel nut.

When I removed the barrel nut from the truss-rod (during the dry run) the thread stripped! I was really scared thinking that the truss rod threads stripped, but after close examination, it was the threads inside the barrel nut that stripped. Whew! Glad I had the three-quarter incher! However, the three-quarter incher is quite a bit longer. Wasn't sure if the remaining truss-rod was threaded that deeply. Also needed to make a tool to shave the wood around the existing truss-rod to make sure the barrel nut threaded deep into the neck's truss-rod cavity. Took one of the metric barrel nuts that I purchased and filed the end like a saw blade, sharpened the tip, and screwed it onto the existing truss rod tip. Don't have a picture of that tool, but I think you get the idea - shaved the area around the truss rod perfectly. All I had to do next was to add a washer to ensure the three-quarter inch barrel nut fit snuggly. Here's what the final assembly looks like.

A bit primitive looking, but with a whole lot of slow tightening, the neck is quite straight. Don't want to remove it for fear that the threads in this barrel nut will strip too (maybe I'll pick-up a few during my next visit to the US! Thank God for McMaster Carr!). If you look carefully at the picture below, you might notice that the neck on this 1115 is twisted. I didn't notice until I took this picture myself.

Warped necks are impossible to fix, but twisted necks usually twist in proportion to the string tension so they are not impossible to fix. That means I'll need to resurface the fretboard and refret the guitar which is good because I like bigger frets on my guitars. Won't be able (and don't need to) correct the twist completely, but this will give me an opportunity to further ensure the playability of  this 1115 upon completion. Need to stop for now, but I'll be back in a day or two. I should note that the filled cracks in the top have buffed out really nicely and I also needed to shave down the bridge to improve neck angle when string tension is applied. Really learned a lot during this restoration! Oh poopoo, gotta go! See ya'all around!

Thanks Keldon85!

It's as if the string tension is forcing the truss rod to act like a lever. Once the neck settles into this slightly "levered" position, the neck does not move at all whether I tune the guitar down to "D" or tune upto concert pitch! Since the neck/bowl joint is not moving at all, the problem seems to be isolated to the neck and a bowl bend will ruin the neck/bowl geometry - so that's out of the question (don't think I could do a bowl bend even if I had too!). There is a finish crack right under the area where the neck seems to move so when tightening the truss rod, it almost feels like the wood around the secured end of the truss rod (in the heel) is "soft" (for lack of a better term). If that is the case, I'll eventually have to take the fretboard off, repair the truss rod cavity and install a new truss rod - perhaps another project for another day! Meanwhile, shaving the bridge and saddle down to accommodate the slight neck movement would be the easiest solution, so my goal was to bring down string height by 1.5mm across the board. To do this, I needed to shave the bridge down by 2mm and shave the saddle 3mm.

It was really important to maintain the surface angle of the bridge so the process was pretty slow with lots of measurements inbetween starting from 60 grit sandpaper working up to 340 grit (you can see the top of 2 of the 3 flat headed bridge screws). Also noticed that the saddle slot in the bridge was not flat so I took a millimeter off to flatten the saddle slot and took 2mm off the bottom of the saddle. Taking too much off will compromise the string break angle at the saddle so precision was quite important. No power or dremel tools here! My attention then went to the frets. This was one of the scariest fret jobs that I've done! As I lightly pounded the new frets into position (also used CA glue for extra security), the ultra brittle rosette started cracking and falling apart! Two big chunks fell off the underside of the rosette (pictured below) before I wised up and taped the entire rosette down!

The work became a little easier after the rosette incident as I worked through the refret process. The extra time I spent on resurfacing the fret board was really really worthwhile as there was almost no need to dress the fret crowns after installing them onto the fret board.

Now, the only thing I needed to do was cosmetic stuff like 1). repairing the rosette; 2). sanding and finishing the bridge with WATCO oil; and 3). cleaning up the body finish with wet sanding, compounding, and buffing! While my OFC/BFLG "thread write-up time" requires another day or two, I'm really happy to say that this project (in real time) is now complete and my 1115 is singing! Thanks for the encouragement OFC/BFLG!

Thanks Al!

You know I was encouraged by the most supportive folks here at the OFC and learned from the best right here at the BFLG! I just hope this information might help others struggling with a broken truss-rod or cracked finish. Glad to report this 1115-1 Pacemaker Restoration ends on a very positive note!

After installing the frets and verifying the stability of the neck, it was time to sand and buff out the finish cracks. Taped up the rosette and lower part of the fretboard to ensure polishing compound doesn't get absorbed into the fretboard. Started wet sanding at 220 grit, then moved to 340 grit and on to 1000 grit.

Normally at this point, it's best to shoot the top with a thin poly coat before buffing to ensure all scratches are filled and the buffing process does not cut through the finish down to the wood. However, the poly finish on these Os are so thick (about 1mm) and so hard that I felt going right to the buffing stage would be okay. Since I still don't have an authorized (by the Mrs.!) work area, the project moved to an outdoor bench!

Automotive polishing compound works really well on these hard thick poly finishes while the buffing drill pad makes progress considerably faster. There are three abrasive formulas for this compound; 7, 1, and 0.2 microns. The buffing pad needs to be wased and dried after each formula; and after the 0.2 micron buff, I use small hand buffing blocks to clean up the "hard to get to" areas. After about three hours, cramping muscles, and a bunch of mosquito bites the finish was all shiny and clean.  

Before continuing, the walnut bridge was finished with several coats of WATCO oil. I really like the dark reddish color of this bridge.

After buffing, finish cracks are still visible although they are completely sealed and cleated for stability. It may not be obvious in the picture below, but close inspection reveals a thick (about a millimeter) filled crack in the lower center of the rosette. A cleaner finish could have been achieved had I wrapped the body in rubber strappings when I first sealed the finish cracks at the beginning of this project!

The saddle slot and saddle were modified to achieve the lowest possible string action for this 12-stringer. If ever in the future the fretboard is removed and the truss-rod fully repaired, shims can be added under the saddle to raise the string action as necessary.

Finally, the ultra dried out fretboard was cleaned and wiped down with lemon oil twice. Strung her up with EJ41s (at this point this 1115 won't take anything more than extra-light strings), tuned her up and voila!

Not the easiest playing 12-string, but tunes to concert pitch (will tune down for daily use, of course) and sounds beautiful. It's quite loud and responds dynamically to light picking and strumming. It's been a long and arduous journey. The guitar is not perfect, but I'm really pleased with the results. Will eventually remove the fretboard, repair the truss-rod cavity, and install a new truss-rod, but for now this 1115-1 is singing again! YES!

Thanks for for the encouragement and for following this intermitent journey!

Hi Ken,

Somehow I missed these latest round of updates.

Congratulations on getting the guitar to this finished state.

I'm sorry all this work resulted in a guitar that is not 100% playable, through no fault of your own.

From reading through your posts, it sounds to me like the problem isn't with the neck, but with a collapsing top.

There is one potential solution to help get the action lower. It's called the JLD Bridge Doctor.

It's available from Stewmac. The one you'd want is the screw mount.

I have one on my old Yamaha 12-string. While I don't have one on any of my Ovations, I have read of a few people who've put them on Ovations with success.

Mostly I've read about it on the Facebook Ren-Ovation group. I'm not sure if you need to be a member to see the posts.

See: Ren-Ovation Nation - Bridge Doctor

Mike Murphy, one of the FB group regulars put together a YT video detailing how he successfully installed one on a 2058TX 12-string.

See: Ovation 2058TX 12 string guitar bridge doctor installation

Dan

I found a YT video where the guy compared how the guitar sounds before and after Bridge Doctor installation.

See:  Bridge Doctor Effect on Acoustic Tone

I agree with his assessment that the guitar did lose a little sparkle.

Give the choice of a guitar that's basically unplayable due to excess string height and a slight loss of sparkle, I'll take the loss of sparkle.

Also, with excessive string height comes the loss of intonation as you play higher up the neck.

Interestingly, Breedlove guitars come with their version of the Bridge Doctor.

See: Breedlove Guitar Support: Bridge Truss System

This video also explains how the BD should be adjusted.

Wrong! Pulled my straight edge back toward the tail block and a completely different story unfolded! For this measurement I laid the straight edge flush to the right side of the top (meaning the visible gap, 2.5mm, is halved to 1.25mm for each side). That's significant...

But the big mistake I made was the vertical sinking of the top which I only measured when I first got the guitar. I assumed the guitar was strung up when I took the measurements, but review of my old project photos shows my neglect - no strings! Here's the re-measurement I took after reading Dan's suggestion...

The angle makes it a bit difficult to see, but the sink is almost exactly 2mm without strings! Took a similar measurement on the otherside of the rosette with identical results. Since pre/post measurements were taken without strings there is no way there can be any improvement with strings. That means the top sink worsened after the top cracks were repaired (actually would've made sense if I had thought about it a bit more), and that's the amount I had to shave off the top of the bridge! Coinkidink? I think not!

That means I may never need to remove the fingerboard afterall (assuming the current remedy holds)! If I "Doctor" this 1115-1 up it should be back to proper dimensions! It might lose some shimmer on the top-end of her voice, but I like my guitars sounding a bit darker anyway so no problem there!

Been playing this 12er a bit each day since it's been repaired. The string's soft break angle over the saddle makes this guitar feel a bit loose, but it's definitely playable and it sounds just majestic (even compared to my now collapsed and waiting for a new top Fxxxxr F330)! No wonder Detlef and 2wheel go on and on about their 12 stringers! Yesterday I ordered the Bridge Doctor from Stewmac, and my son (remember delivering my highly coveted 1612 to my son, Dan? He's graduated, and employed in the area now) is traveling to Japan in 10 days or so; he'll deliver it to me at that time! Hopefully, I'll be able to avoid intermittency and get this one completely done. Meanwhile, gonna start working on a custom TR cover to clean things up a bit...just a bit more and this 12er might be back to 100% (well, maybe more like 90%)!

Hey, thanks again everybody! Should be back in two to three weeks!
Happy strumming!

While waiting for the Bridge Doctor to arrive, I decided to get to work on my truss-rod cover.

Couldn't find anything that fit perfectly, but found these covers from SCUD.

The DM-802 wasn't long enough so went with the DM-803 which was closer in shape to the original TR cover but too long. In either case, the cover needed to be shaped a bit to fit properly. The barrel nut and aluminum spacer assembly is just a tad proud of the face of the headstock so I'll need to shape the TR cover with a bit of a dimple.

So I started by marking a rough pattern on the back of the DM-803 including a cutting line that will shorten the cover to fit this application.

The truss rod adjustment wrench actually had the perfect contour so heating it up and pressing it into the back of the plastic DM-803 should create the dimple I need. Made a wooden jig with the correct groove width to allow the plastic to stretch and form the needed dimple. Slowly heated the wrench and tested it against the plastic surface (not much heat was needed to help the plastic begin to deform and stretch), then gradually increased the pressure/heat and achieved the needed contour.

Plastic flashing needed to be shaved off. A bit of scraping, filing, and sanding was needed to clean things up too.

The under side of the TR cover is a bit of a mess, but it works as long as you don't look under the hood!

The DM-803 is a bit wider than the original cover so it fits snuggly under the strings. That means I can secure the cover with just one screw (like my '97 Collector's). It's not perfect, but it's much easier on the eyes than looking at the homemade hack solution applied underneath!

Hoping the Bridge Doctor, due to arrive in a week or so, will completely resurrect this 12-Fret beauty! Maybe one more post to cross the finish line!  

Frankly, I'd just as soon forgo the drama, but being the hack that I am, there's bound to be poor judgment, bad execution, and cringe worthy moments along the way. The short version is, the Bridge Doctor is installed and in waiting for test/review 48 hours from now. Details to follow...

The Bridge Doctor is designed for typical flat-top applications; but our beloved O's are not typical flat tops are they! If you haven't checked out the YT videos that Dan shared in an earlier post, I would highly recommend checking them out before installation. I did, and found that a tail piece or something similar would need to be added to my 1115-1 for a successful installation. The BD's tension bar will not hold its position against the tail area of my deep bowled 12-stringer. To ensure the force of the BD's tension bar was distributed as widely as possible (although unlikely, too much focused tension might possibly sever the bowl and top in that area), I opted for a fairly large piece of Hinoki (beautiful, local resonant lumber).

Taking measurements from the outside of the bowl, the Hinoki was contoured to fit snuggly. Measured the lateral radius at 25". The vertical arch was drawn on cardboard using the pencil/washer method. Transfered the measurement onto the wood block and sawed, filed, drilled, sanded and routed away. Until I got this unremarkable looking block of wood...

Pretty nice, aye? Even accomodated for the strap button nut and drilled the hole to allow for the bolt with great precision! Whew hoo! Wiggled this baby into position and found some hinderances that I should have remembered from my first inspection of this guitar...

Not sure what all that wavy stuff north/east of the strap button is... but it's hard and looks like folded fiberglass hardened by resin. Whatever it is, it will not accomodate my tail piece unless I grind away at the bowl... switched gears and decided to redesign the tail piece into a smaller "tension bar catch" or something...

Only problem with this design is that vertical and horizontal centering becomes a bit of a hit and miss proposition! Not ideal, but it beats grinding the inside of the bowl any day! Will need to use the strap hole button bolt as a centering tool and route a center marker on the tension bar catch to make sure I can feell my way to center when I install this into the bowl. Now it's time to install the Bridge Doctor!

These are the Bridge Doctor parts as they come in the package. There are three positions available for the nylon mounting post. Ovation bridges are deeper to accomodate the pinless top loading string design so position "3" (furthest to the right in above pic) is best suited for our Os. Fortunately, the Pacemaker already uses three bridge mounting bolts, and all I need to do is remove the middle bolt, drill for the slightly larger diameter BD mounting bolt (meaning the original bridge bolt that came on the guitar cannot be used to secure the Bridge Doctor into position) and be on my merry way. So I heated the bridge bolt with a soldering gun (just-in-case the bolt and nut were glued together with epoxy or CA glue) and got my quarter inch socket to remove the middle bridge bolt/nut under the bridge and voila...

The bridge bolt cracked! Oooookay... how 'm I gonna remove the bolt now? So let's try screwing the bolt out from the top... no movement! Tried everything I could without damaging the guitar, stripped the flat head bolt top in the process and took a nice gouge out of the bridge and top finish (as seen above)... 

Okay, now I'm really up the creek without a paddle! Gosh I hate drama... took forever to dig through my tools and find my small diameter metal cutting drill bits. Drilling out the bridge bolt remnants was really really scary!

Fortunately, I was able to drill straight and true through the center of the existing bolt. Continue to increase diameter until I got to the diameter I needed! Now it's time for a dry run! Secured the tension bar catch with double stick tape (fit is just perfect!). Secured and positioned the Bridge Doctor. Measured and cut the tension bar to fit my application.

Verified alignment and tightened the tension screw with a 3/16th inch allen wrench. Everything was really stable, so went in for the final installation and everything is holding really well. The strap lock bolt, the precise contour, and the double stick tape looks to be working really well. Probably won't need to epoxy it into position so essentially I'm FINISHED! Wow that was difficult! The installation guide says installs "in 30 minutes!" Maybe for most folks, but for this hack it took days!

It's taken years to get this guitar out of shape so it'll probably take time for this top to get back into shape. Thinking I'll slowly increase the tension on the tension bar over the next 48 hours, then test for playability and sound and see where the pros and cons of the Bridge Doctor are for this 1115-1! That's it for now! Thanks for letting me share my journey OFC/BFLG! Be back in a couple of days!

Hey, thanks seesquare, Dan and Al. I've been messing with the bridge doctor adjustments over the last several days and started to get familiar with this very cool tool. I think it might be helpful to have a separate thread to discuss the unique application that the JLD Bridge Doctor might have with guitars manufactured by Ovation. I also think I've discovered some aspects of this tool that I'd like to share as well, but that's for another thread and another time...

As for this 1115-1 the JLD-BD works exactly as it is designed to (just as Al predicted). Installed according to the instructions provided, the JLD-BD removed the ever present buldge between the bridge and the tail end of the guitar. Tighten just a bit to allow the tension bar to spin but not wiggle and the results are immediate...

However, at this setting the JLD-BD did not help the vertical dip (the fret board extension dipping into the sound board) at all. The following pic was taken with the same tension bar settings as the pic above (it should be noted that, when strung up {DAd EJ41s} at these settings, I could not decipher any noticeable difference in the guitar's tone/voice - beautiful ringing shimmering quality with a rich natural chorus)...

Spent quite a bit of time adjusting the tension bar to find the ideal dip/buldge control. Starting at the "spin w/ no wiggle" setting above, the tension bar was tightened a full 3-rotations or 1080 degrees. At this point the tension bar does not spin at all. It is not bending but it is tight. At this extreme setting, the vertical dip has been halved...

...and buldge behind the bridge has also become a dip.

Can the tension bar be tightened some more? It CAN..., but a whole lot more turns and the structural integrity of the tail area of the guitar might be compromised. So I called this "my 1115 ideal mechanical setting" and strung her back up with EJ41s, and as BB King used to sing, "The thrill is gone, baby!" It makes sense. With this much tension, the JLD-BD is now hindering the top movement and the voice has darkened while the dynamics, the shimmer and the sparkle have been curbed considerably. Wanted to see if swapping strings to some 8/20s (as opposed to the Phosphor Bronze material used in the EJ41s) would help, and to my pleasant surprise they did! Here's the belly buldge with the guitar strung with Martin 80/20 extra lights...

Interesting! You can see that the belly buldge turned belly dip at "my 1115 ideal mechanical setting" has practically flattened back up! After string tension is applied, this is how the vertical dip looks...

So this looks pretty good and the 80/20s sound decent (although not nearly as loud). Now, the question is "Has the JLD-BD improved the 1115's playability?" The answer is "Just a little bit..." I should clarify that this product is not intended to improve my guitar's string height (action). However, leveling buldge and dip in the guitar top often leads to improved playability. In this particular case, after achieving "my 1115 ideal mechanical setting," the neck angle to bridge is perfect; but after string tension is introduced to this guitar the action changes as follows (tuner at 432Hz as concert pitch and string height measured at 12 fret);

With E strings tuned down to D: 6th string - 3.50mm; 1st string - 2.70mm

With E strings tuned down to D#: 6th string - 3.70mm; 1st string - 2.85mm

With E strings tuned to E: 6th string - 4.00mm; 1st string - 3.00mm

Here's what's really weird... the JLD-BD's "my 1115 ideal mechanical setting" is holding. The repaired truss-rod is also holding and the neck relief is not changing and the neck/bowl joint is stable! Argh! Unbelievable! So what in the world is moving???

That does it! This fingerboard is coming off, and I'm going in for a truss-rod replacement! Not sure when I'll get to it, maybe in the summer? Messing with the JLD-BD has taught me so much in the last few days and has helped me to isolate the problem. There is something really weird happening in this neck's truss-rod cavity. Don't know what it is, but I'm gonna find out!

Feeling a really special attachment to this 1115-1 Pacemaker after all that we've been through. I've got some really nice kaede maple sitting in my shed so maybe a full neck rebuild (in my dreams right!)? All I know is I'll either destroy this "O" to oblivion; or repair it to glory... you know, the "If I can't have you, nobody can." syndrome! Wah ha ha ha... Wah ha ha ha ha!

The removal was much cleaner than it might look in this picture. Took about two hours of slow heating and spatula-ing. Some of you might be able to tell just by this pic that this fretboard had been removed before. There are two plastic dowls to align the fretboard during factory installation. This fretboard had four dowls; 2 plastic and 2 wood. The wood dowls were placed randomly as seen in the next pic (the red arrows point to where the wood dowls were.

I think the green "1115" written on the neck is from the factory. Very cool! I should find some irregularity near the neck joint of this guitar. Hmmm??? That doesn't look right!

The area in the blue circle is definitely not factory spec! The neck join cavity is all filled with some kind of adhesive. Could be epoxy, but it looks and feels like CA glue. I'm pretty sure I'm going to find some structural integrity compromising condition when I dig the adhesive out of this neck joint cavity area! So far the prospects look very promising! Hopefully some work to alleviate this guitars regret for having ever met me might be possible from here! Time to dig-in!

Before cleaning the back of the fretboard, I need to see if the neck joint cavity is really repairable. The adhesive in the cavity will need to be cleared out; and to do this. I'll use my soldering iron and just drop it on to the adhesive in the highly suspect area. If I just let the soldering iron rest on the adhesive it will melt and keep sinking until it hits wood. The process is repeated until most of the adhesive is removed. This stuff is not CA glue afterall. Definitely epoxy...

You'll notice that the spruce top stopped my sinking soldering iron, but was marked quite severely in the process. Since this area will be covered by the fretboard extension, the cosmetic condition of the top is not an issue for me. Notice the amount of wood that was removed from the neck block to get to the butt end of the truss rod! Here's a full shot for a better perspective on the size of the cavity!

It's huge, and it is the main source of this Pacemakers problems. The neck end of the truss rod was pounded lightly with a small hammer to see if the truss rod would even move that's why there's a bit of space between the neck and the butt of the truss rod. It looks like a truss rod swap was attempted in the past and the previous repair person got this far. They cut/drilled/gouged wood out from the cavity in the neck joint in an attempt to remove the rod from the butt-end. The truss rod didn't budge so they tried to pull the truss rod up and out from the headstock-end and that's why the truss rod was bent upward. When that didn't work they probably gave up, filled the cavity with epoxy and put everything back together. I've seen videos where the truss-rod is just yanked out of the neck and the thin strip of wood covering the truss-rod channel just crumbles out of the way; but that's not going to work with this Pacemaker. The thin strip covering the truss-rod channel in this Pacemaker is mahogony which won't just crumble out of the way so it's imperative to make deep cuts (down to the truss rod itself) along the length of both sides of the strip with an exacto knife, remove the wood strips and proceed to remove the truss rod. Here's the remnants of the mahogony strip...

Here's the truss rod channel cleared of the mahogony strip from several angles...

To remove the truss rod, I continue to remove thin strips of wood from both sides of the truss rod channel with an exacto knife (this process took quite a bit of time). A thin rope was threaded into the neck joint cavity around the butt end of the truss rod...

Lightly pulled on the rope and...

I'm face-to-face with the primary source of this Pacemakers problems! The TR channel is now completely cleared and a decision needs to be made whether to throw in another traditional one-way TR or install a more modern two-way TR. Both will require some work. For the one-way TR, I'll need to make another TR channel cover that will fit the contour of the of the existing TR channel. For the two-way TR, I'll need to fill the current TR channel with a properly contoured channel filler and route a new channel to accomodate the modern truss rod. Since both will require considerable work, I'm thinking two-way TR at this point. The more pressing question is how will I repair the neck joint cavity that currently looks like this...

Rebuilding this area will be best accomplished by removing the neck completely; and with this much removed already, a neck reset may not be out of the question, and converting to a bolt-on configuration would be most desirable, BUT pulling the neck off of these older 111X Ovations is quite a scary task. I'm not at all sure that the neck can even be removed safely at this point! Will need to dig around to better understand how these necks are secured into the neck block before I proceed.

The saga continues! I'll be back in a few days!

Thanks for the valuable tips Keldon85!
Back when I first started visiting this site, I was looking for ways to repair a lifted bridge on a 1117-4. At the time, BFLG heavy hitters like MWoody, seesquare and Dan Savage were doing "bowl bends" and in one of those threads, one of the veteran OFC'ers said, "it's almost impossible to remove the neck for a neck reset without destroying the top/bowl on early ovations." Don't remember who it was, but I remember the statement - I think they even went on to say the bowl bend was the "only" solution for "early" ovations. That kind of stayed with me. Since then, I've reset several Celebrity necks and K-bar equipped Ovation necks; but never a 111x model O. Bigger than the impression left by that statement is this...

That dowel in the blue circle. What is that? I keep thinking it's one of those dowels that spread when the pin is hamered into the housing. If it's part of the structural integrity of the neck joint, proper removal of the dowel/pin will be essential for a proper neck removal. I can see myself just hacking away at this thing only to find that this dowel makes neck removal "impossible." Figured this thing would have been ID'd long ago on the OFC, but my searches yielded nada! I searched the internet for some hint as well, but haven't come across anything conclusive.

There was a thread on another site that expained that an insert was made in the neck block of Os to inject adhesives into the neck joint. Is that what this is? Oh, btw, (just-in-case) the pic above was downloaded from one of Dan's previous threads, cropped and added the blue circle for easier IDing (Dan, I figured you wouldn't mind).

The gouged neck block will make it easy to accurately drill steaming holes into the neck joint. I suspect the neck will come off with a minimal amount of steam so no need for my Freezer Bag solution here. Then the mortise/tenon can be fully repaired. Install the inserts into the neck for a bolt-on conversion. Cut the TR channel for a two-way TR, glue the fret board back into position, refret, take care of minor cosmetics, string-up, set-up then I should be done...

Hope I'm not beating a dead horse here but, getting a clear ID on the above would go a long way in giving me some peace of mind with a neck removal/reset for this 1115. As always is the case, Thanks BFLG!

Hello OFC/BFLG! Hope you all had a good weekend. Really hot - like a sauna - over here in the Land of the Rising Son.

Been staring at that neck block black dowel-like thingamajiggy every chance I get over the weekend - wondering if it was something else. Finally decided to take a chip at it with a chisel. If it's epoxy, it'll chip. If it's a dowl the black paint should come off and reveal wood, aluminum or some other material. Lightly hammered at the dome and...

The dome chipped off...

It's epoxy! Of course, you all probably knew that already, right? So epoxy was injected into the neck joint after the neck and body were clamped into position? Interesting... Also, interesting is that the pic I borrowed from Dan's thread and this pic both show that the neck block has two epoxy "injection" holes. For this Pacemaker only one of the injection holes were used while the other is only partially "drilled" (the hole isn't drilled through the neck block to reach the joint).

With some added peace-of-mind, the neck joint was cleaned using my soldering gun to heat, melt and remove excess epoxy. As the work progressed my mind began to inquire if steaming this neck-off was even possible...

Epoxy basically surrounds the neck joint and this stuff is intense! Set my soldering gun temperature to 110C degrees and this stuff is not budging. At 400F/200C degrees (highest setting), the epoxy melts readily. Reminded me of Hysol 9462 which (I think) withstands heat up to 250F/120C. That means this neck can't be removed with steam!? Wondering how the Mother-ship ever did neck resets on these older Os?

NOW I'm beginning to see why the OFC veteran said, "it's almost impossible to remove the neck for a neck reset without destroying the top/bowl on early ovations." I can almost hear Darth Sidius laughing and saying, "Young fool! Only now at the end, do you understand!"

Really don't want to destroy the top or the bowl... Maybe time to invest in a heat gun? New 2-way truss-rod arriving tomorrow, so I can't give-up... need more time to think! Any corrections, suggestions, advice would be most welcome/desired! Thanks for letting me share my journey OFC!

Wow, Ken!

You're off the edge of the map, Mate. Here, there be monsters.

What was the original problem with the neck? Did it have too much relief? (forward bow)

I wish I'd thought of it sooner, but there's an old trick for necks with too much relief that tightening the TR won't fix.

This requires the fretboard be attached to the neck. Basically, you remove the frets, then install frets with a slightly thicker tang. As you install the frets, each one acts as a wedge that exerts pressure that causes the neck to warp backwards.

What I find interesting is the 'glue' holes in the neck block have witness marks made by a blind or 'T' nut.

The way they're installed in the neck tells me they were probably used to clamp the neck block to the bowl while the epoxy cured. Obviously, these are removed to mount the neck.

If these were used to inject epoxy into the neck joint, as it appars in the bottom hole, then it will pretty much impossible to get the neck off the bowl.

I think you're on the right track at this point. Since the fretboard is off the neck and you'r replacing the TR, I would continue on this path.

When you're ready to glue the fretboard to the neck, clamp it like is shown below so the weight of the guitar is all concentrated at the neck. This should warp it back into place. Then, when you glue the fretboard, it should pretty much fix the forward bow due to shear forces between the two pieces of wood.

If the neck still has excess forward bow that can't be taken out with the TR, you can always fall back on the thicker fret trick I described above.

Hey, thanks for the feedback everybody! As usual your input really helped me think through the neck removal carefully. Was a bit limited on options, but I'm glad to report that the neck's been removed and both the body and neck have survived the process with minimal damage!

Thought maybe my BBQ grill imported from the USA might work; but naw...

Maybe fill the bowl with some stuffing and enjoy some Barbecued Pacemaker?! Lol! Some seesquare humor was definitely needed at this stage of this project!

Sawing the neck off at the joint would have made this a much easier project for sure, Keldon85! Your logic is definitely sound! With this Pacemaker, the neck/bowl joint itself was solid and not moving, but if the whole bowl around the neck joint is moving which I think it is, the newly bolted on neck would continue to move and cause problems. So, I figured the only way to really fix this thing was to remove the neck, reinforce the bowl, install new truss-rod, then reassemble. My fingers are crossed!

Thanks Al! That sounds like an awesome product. I looked all over the internet in Japanese and English and came across some aerosol sprays that are used to protect hair from heated curlers and hair dryers, but could not find anything readily available in this corner of the world. If you ever come across the product's name, please let me know. Depending on application parameters a heat protective spray could be really beneficial - especially for instruments that use a lot of space age adhesives! As you've identified, localizing heat is the key to ensuring removal doesn't end in catastrophe!

Thanks Dan! Yup, I installed jumbo frets with wider tangs in hopes the resistance would prevent the neck from bowing (and it did), but the issue was not neck bowing or too much relief! As a matter of fact, after removing the fret board and truss-rod from the neck, the neck is relatively straight - even the slight twist is gone! Weird, right? I think the issue is that the bowl around the neck joint has softened (for whatever reason). Still in the process of completely identifying the culprit; but in the end, I think the issues are many...

T-nuts! That's what they are! It makes sense that they were used to secure the neck blocks onto the bowls. Right, got it! The T-nuts were removed, the necks and bowls were clamped into position and the holes drilled for the T-nuts were used to fill the neck cavity with epoxy! Saving the luthier from cutting perfect fitting dove joints and securing everything with space age epoxy would decrease manufacturing process time significantly. Epoxy was used as a process improvement to cut down on labor hours and increase product output - especially in the early to mid 70s when Ovation demand was so high. They attempted the same process overseas, but instead of using space age epoxy, the overseas facilities used locally available epoxy (as a cost cutting measure)... that's probably why I see more Celebrity models with neck issues. Whatever people may think today, that is some forward "Mfg process" thinking back in a day when major manufacturers all over the world were struggling with cost/labor ratios (well, I guess that's still a manufacturing struggle today).

So with the limitations that I have, the key to removing this neck safely is localizing heat to ensure only the epoxy in the neck joint is affected. Since there seems to be 1mm to 2mm of epoxy filled space around the dove joint, the easiest way to localize heat (I think) is heating a spatula and sticking it into the epoxy while trying not to directly scorch the wood. Three spatulas were called into service for this task...

Applied direct heat to these spatulas from a gas stove flame for about 30~50 seconds and just pushed the spatulas into the epoxy. Just like the soldering guns, the epoxy gives readily, but once the epoxy returns to room temperature it gets stubborn sticky again. Had to repeat the heat-up and dig-out process for hours on end. After the epoxy was removed from the visible gaps in the dove joint, I drilled two 2.5mm holes in the sides of the dove joint (accurate drilling depth is super important). Stewmac has a product called the heat-stick that is designed to remove necks without steam. I've seen these work on Martins, Yamahas and the like, but I don't think they get hot enough so I converted my soldering guns into pseudo-heat sticks to try and get the epoxy around the bottom of the dove joint area loose. The converted soldering guns have aluminum sleeve with 2mm steel rod extensions that directly come in contact with the heating element of the soldering gun. The 2mm steel rods were inserted into the 2.5mm holes while the temperature was monitored (the temperature is just about to crest 100 C in the pic below). Tried to stabilize the heat at about 140 to 150 C.

My psuedo heatsticks had to be left in this condition for long periods of time. Since I couldn't just leave the heat on while I was out and about, the whole set-up take down process had to be done about 8 times. Probably spent a good 6 hours in this condition (if I exclude my intermittent engagement). The idea for me was to wait until the neck basically fell out of the dove joint (instead of wiggling the neck out and risking tearout), and boy did I wait, and wait, and wait... until finally creakity, crackity, crack... with just a slight nudge and twist the neck came loose and...

Seems a bit of scorching was unavoidable, but the bowl and neck block are firmly in tact. Notice the epoxy piled up in the bottom of the dove joint. And here's the neck...

Apart from a bit of scorching and some minimal tear out, the neck/neck block dove joint are very much intact. Looks like the bowl around the neck block will need to be reinforced; and now that everything is disassembled in good condition, the fun can really start from here. Thinking about how I can convert the bolt-on neck into a no adhesive neck block assembly... the installation of the new truss-rod is going to be interesting too.

I think the TR cavity was the beginning of the demise of this Pacemaker (more about that later), but feeling really good about a full recovery at this point. Sheesh, gotta run!

Thanks for letting me share and helping me to think through this project OFC/BFLG!