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Location: Taichung, Taiwan | Last summer was a mixed blessing guitar wise. I was able to pick up a Hohnor G3T while in the states and it fit in my backpack in the overhead to get it back to Taiwan. It was fun having it as a travel guitar on a mission trip to the Philippines using a little JBL speaker. Plenty loud for our needs. However, while I was away from Taiwan, the three guitars I repaired last winter de-glued! My wife said she was sitting in the living room and suddenly a “prang” sound came from the office and upon inspection found the guitar decapitated. The other two I discovered the week I got back to Taiwan and my co-worker handed me the remains. I have been putting off their resurrection attempts until now…or in the nearer future looking at my schedule ahead. 
a picture of the carnage...oh the horror! All three were broken peg heads and I used my old standby “Titebond Original Wood Glue”. 
Here is the old bottle of glue next to the amazing JBL Bluetooth speaker! I read years ago that it was great stuff and I haven’t had any problems with it in the past doing similar repairs. Maybe my old bottle is past its shelf life. Maybe the high humidity and higher heat of summer added up on all three to do them in. They all are cheap guitars, two of which my co-worker was using for guitar classes for youth in the community. They don’t have to be perfect or pretty or even sound that good, but the strings need something solid on each end to stay in tune! My questions to those of you who know (the glue geeks!): 1) What is the best way to clean the old Titebond off/out so the new glue will stick well? 2) What glue should I use that will hold in our high humidity? I know hide glue is the traditional stuff, but our humidity here can be overwhelming. I am considering the possibility of using epoxy, like Loctite Hysol 9462. I might not need aerospace quality for these beaters so something similar would work. But someone said not all epoxy is the same and I do not want to keep doing this over and over again. I am starting up on this because I have a pastor coming out from the New York area in a few weeks and if I need to, I can have him bring a few things. Any suggestions you have are very much appreciated! Here are close ups of each of the broken heads. Two are pretty clean and one was like putting a puzzle together the first time. I'm guessing it will be harder to take apart. Unfortunately my co-worker says that is the one with the best sound. 
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Location: undisclosed | In your climate I'd use epoxy with the addition of a inlayed carbon fiber uni strip bridging the joint for piece of mind. Finished it will look like a short black stripe but I think you are beyond appearances here and just want some players. Epoxy is a mechanical bond so scrape off old flue but you want a rough surface for adhesion. Without the carbon or a wood inlay I think the joint might creep in your climate and eventually let go. |
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Location: Pacific Northwest Inland Empire | As to getting the old glue out- maybe putting a wet rag on the broken areas a few hours, to moisten the remaining glue, then warming it up with some steam, then scrape out whatever comes loose. Just guessin'; I'm not the Chief Geek, around here! |
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Location: undisclosed | I think we bottom feeders are more of a collaboration than a hierarchy....
Procedure wise I;d glue the pieces together first then cut a channel after it is dry across the break for the carbon fiber insert. While you could laminate the carbon first I'd be tempted to laminate the uni directly in the channel to avoid secondary bonding. You want it to finish above the neck surface so you can bring it down flush, filing sanding etc..... |
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Location: Yokohama, Japan | Cavalier - 2016-02-15 4:26 AM
I think we bottom feeders are more of a collaboration than a hierarchy....
+1
Oh man Peter D, my heart hurts for you...been seeing a lot of this kind of stuff on the BFLG lately with BanjoJ's dropped Ute and all...I think Cavalier has it right, the humidity out in your neck of the woods is punishing at best. Our summers in Japan are very humid, but probably not as severe as Taiwan. Titebond will not provide the kind of enduring adhesion you need. A carbon insert will definitely give the joint extra strength, but with Hysol 9462 you may not need it. If you've got a Pastor friend headed your way, I'd go with Hysol 9462. It's handy stuff to have around the shop. They are a bit costly, but can be carried easily (he won't want to hand carry it on to the plane). Make sure to get the application gun if you order it. The adhesive is super powerful (although it doesn't cure completely, it gets very hard and immovable after about 8 hours, so I would prepare some simple alignment jigs to make sure the neck doesn't clamp-on crooked. Once the stuff cures there is no turning back. When dry, it maintains a light tan or flesh tone color, so a thin adhesion line will show up... but then you mentioned that the result didn't really need to be pretty, so you should be okay there.
I would take seesquare's advice with the removal of the old Titebond. Dip some rags in boiling water, and squeeze out the water (you'll need some good thick gloves to do this, actually just hot tap water might be good enough for Titebond). Just lay it on top of the severed joint, and the glue should come loose. You can also keep the entire area kind of warm and humidified (keeps the glue soft) by heating the wet rag with a hair drier. If direct contact using a wet rag is a bit risky, I've kind of grown fond of pouring boiling water into a Ziploc Freezer bag, and applying the bag to the severed joint. This method definitely takes more time and patience, as the heat may not get into deeper crevices that need to be cleaned out.
BTW, I see one of your guitars is a bowl back guitar. Is the bowl made by Ovation? Like an Applause for the Taiwan market? Interesting. Good luck and let us know how it goes!
Edited by arumako 2016-02-16 6:49 AM
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Location: Taichung, Taiwan | I'm trying to see if i can find the right epoxy here. Are there other more common or generic names for the kind of epoxy i need? At this point i can find "quick set" and "slow set" but i haven't found any temp ranges or other identifying stuff. I need to find a more technical store than a regular hardware store. I may have to buy it on line and have it sent to someone to bring out to me. Will the Stew-Mac epoxy work as well or who should i get it from that will ship?
The "carbon fiber uni strip" would be a whole 'nother thang. I might be able to locate some carbon fiber pieces...or at least something that they tell me is real carbon fiber at appropriate prices, but i have never "cut a channel" and put one in anything. I've glued stuff with epoxy before and i've glued pegheads back on (with obvious mixed results) What tools would i need to cut a channel for a carbon fiber uni strip and how would i do it? At least one of the guitars doesn't have much thickness of wood to work with before running into the tension rod. I would be fun to make a few bionic guitar necks!
The bowl back is an Ovation knock off, a shallow bowl "Gemini Model #OF3509 Made in Korea". It was given to me years ago without the head since it had broken off and had been subsequently lost. Last winter i finally tried to graft a slot head from a classical guitar onto it, just because i like slot heads. it looked good and the shallow bowl fit my expanding deep bowl belly better, but it didn't sound very good.
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Location: Yokohama, Japan | PeterD - 2016-02-15 9:28 PM
I'm trying to see if i can find the right epoxy here. Are there other more common or generic names for the kind of epoxy i need? At this point i can find "quick set" and "slow set" but i haven't found any temp ranges or other identifying stuff. I need to find a more technical store than a regular hardware store. I may have to buy it on line and have it sent to someone to bring out to me. Will the Stew-Mac epoxy work as well or who should i get it from that will ship?
The "carbon fiber uni strip" would be a whole 'nother thang. I might be able to locate some carbon fiber pieces...or at least something that they tell me is real carbon fiber at appropriate prices, but i have never "cut a channel" and put one in anything. I've glued stuff with epoxy before and i've glued pegheads back on (with obvious mixed results) What tools would i need to cut a channel for a carbon fiber uni strip and how would i do it? At least one of the guitars doesn't have much thickness of wood to work with before running into the tension rod. I would be fun to make a few bionic guitar necks!
The bowl back is an Ovation knock off, a shallow bowl "Gemini Model #OF3509 Made in Korea". It was given to me years ago without the head since it had broken off and had been subsequently lost. Last winter i finally tried to graft a slot head from a classical guitar onto it, just because i like slot heads. it looked good and the shallow bowl fit my expanding deep bowl belly better, but it didn't sound very good.
You can get Hysol 9462 here (temp raqnges and other data included)...
http://www.mcmaster.com/#loctite-hysol-epoxy-adhesives/=xzueu2
...it's about the sixth row down. You'll want to get the dispensing gun as well. McMaster Carr will not ship Hysol to international locations, so you'll need to have it shipped to your friend and have him hand carry it to you. If you go with Stewmacs stuff, I'd definitely use the graphite shims Cavalier was talking about. Usually, the longer the set time the stronger the bond...but I don't think Stewmac can ship epoxy internationally. High grade epoxies are highly flammable and suppliers are often not allowed to ship items directly to overseas customers.
To place the carbon fiber strips, you'd need a Dremel type tool w/ router or cutter bit. If you aren't used to making precision cuts in wood with tools like that, you'll want to make sure you get a lot of practice on blank pieces of wood. Better yet, just go with the Hysol 9462, and you probably won't need the carbon fiber strips at all.
They sell Ovation knock offs like those in Japan too. Several different flavors with companies like Morris Tornados and such...they never quite sound like the real thing in my opinion, but they are interesting! I like slot heads too. Thinking about converting the headstock on my CC54i into a slot head...cool!
Edited by arumako 2016-02-16 8:44 AM
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Location: undisclosed | For the channel I'd go low tech and use a simple utility knife and straight edge to dimension the channel, less than a cm 6mm or so wide. Once you cut the sides and inch or so past the break each direction use a narrow chisel to cut the depth. It's safer to whittle a little at a time than bring out the power tools. The channel only needs to be a few mm deep. I'm doing this same repair on a mandolin for the extra strength.
Uni carbon tape can be gotten through marine supply stores like Defender, Jamestown Marine, and West Marine, they all ship. I use WEST epoxy and fillers, available from the same sources, with excellent results because I always have some on hand for boatbuilding. If it's any consolation I've saved necks that were in more pieces, stain or paint can help cover glue joint lines with some clear finish on top.
Hey Ken you could laminate more thickness onto the headstock for a slot head conversion, a nice veneer would spruce it up. |
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Location: Taichung, Taiwan | Well, this week just suddenly filled up with stuff, so i won't be able to search for epoxy (and carbon fiber strips?) till next Monday. If i can't find stuff on Monday, I'll have to see who can ship it to my friend in time for him to bring it out to me. I can probably find some small chisels, but I think i may try it with just the super epoxy. i just thought about some kite sticks i brought back from the states. i think they were supposed to be carbon fiber...would a carbon fiber rod work? |
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Location: undisclosed | Most likely, you could try snapping a short sample to see how strong it is. The main advantage of using the fibers is you can have a more shallow channel and spread them out to get in more material with a wider slot if depth is a issue. I'm busy this week too but I'll try to get the mandolin done and post some pictures. In this case it is a safety for a fracture that didn't completely sever the neck. It already holds pitch with the neck glued but I'm putting this one in to save the day if it ever drops. |
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Location: Yokohama, Japan | Cavalier - 2016-02-16 12:24 AM
Hey Ken you could laminate more thickness onto the headstock for a slot head conversion, a nice veneer would spruce it up.
Not sure if I'll actually do it, but I do have a 1mm thick CFRP plate that would look really cool as a headstock face plate. I also got my hands on some nice hockey sticks that are made out of Yellow Birch just in case I need to add some width to the headstock too...oh sorry, off topic...
@PeterD - Like Cavalier said, you'll need to test the rod for stiffness, but I've seen CF rods used on several neck repairs in the past. They were added after the glue dried by drilling holes. You've got to be real careful about the drilling angle and depth to get good strength in the repaired joint, but the CF rods were glued into the drilled holes like dowels. If you're pretty handy with your chisels (they've gotta be sharp), chiseling some shallow channels and gluing in the rods might do the trick. I think it really is going to depend on the type of epoxy you use.
FWIW, I've had good results using ZAP Z-Poxy in the past (another Dan-the-man suggestion). These guys will apparently send the stuff internationally to you.http://www.ebay.com/itm/Pacer-Zap-PT39-Z-POXY-30-Minute-Epoxy-Resin-8oz-Pack-PT-39-LARGE-/271908840249?hash=item3f4f07a339:g:RpIAAOSwLVZVhxCh
A friend of mine was about to toss this Ibanez so, I asked if I can keep it and experiment with it. I used this stuff (I don't think it is ideally suited for this kind of application, but..not knowing any better, I gave it a whirl), and it seemed to work out okay... 
Used some jigs to make sure the alignment was fine and clamped it up. Waited 72 hours and finished it to this... 
My friend came by and saw the repair; and so I gave it back to him, and he's been playing it since (for about 1.5 years). However, if this was more than an experiment, I would have definitely used the epoxy + some CF strips to add rigidity. I hope this helps...if any of you guys think the 30-minute ZAP is not right for this please chime in!
Edited by arumako 2016-02-18 2:38 AM
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Location: undisclosed | Haven't used zap, keep tabs on your friend's guitar for a test.
The thing I should add about many epoxies such as WEST is that you need to use fillers with them for correct bonding. Various powdered additives can either improve bonding or fairing/filling depending on the need. I uses colloidal silica as a thickener for bonding. Mixed to a creamy peanut butter consistency it will fill gaps and keep glue in the joint .Strength is improved over straight epoxy.
The other thing is not to use too much clamp pressure as it can force the epoxy out starving the joint. Ideally you want to use just enough pressure to keep things in place. |
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Location: Taichung, Taiwan | Wow, arumako, that looks nice! Satin black looks nice.
Thanks Cavalier for the tip on not too much pressure. It makes sense, I usually try to get things as tight as possible, not thinking it could push all the glue out! I'll go for a little gentler approach when i get a chance to try. |
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Location: undisclosed | Good luck Peter! If you try laminating the carbon fiber strands into the channel there you want to use straight resin without fillers,. If you use a rod you do want fillers with the WEST style resin.. I'm trying to get to my mandolin this weekend so pics will be coming at some point.
Edited by Cavalier 2016-02-19 9:50 AM
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Location: Taichung, Taiwan | Don't rush on my part. It may be a while be fore i have time to get to them now... |
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Location: undisclosed | I've done the repair minus the final touches. Couple notes. I left the finish on the neck for this job though I plan on refinishing eventually. The first shot shows the glue areas of the original headstock split. These were champhered out to make getting the epoxy in easier.
The tape is there to protect the neck while cutting and provides a bib when doing the laminate.
The picture of the roughed in slot (before sanding) shows how the ends taper flush to avoid point loading. For the same reason the bottom of the slot has rounded edges. The crack repair approach worked well, where the slot crosses a crack there is good glue penetration and a solid joint.
The uni strips are wetted out and layed in the slot, I used shorter ones to build up the center away from the tapered ends. Once I had things thicker than needed I carefully wrapped the laminate with tape to apply pressure and squeeze out the extra resin.
I let things dry till it was kicked off and dry to the touch but still a little green. The tape was removed and the bulk of the excess laminate was trimmed off. The tape made the over lap from the slot easier to trim without damaging the neck.
The compound contours of the neck were restored onto the laminate and final sanded. The last picture shows a couple uni strips to give the idea, straight tow would give a less wavy appearance but I have lots of uni sitting around. A couple coats of water base gloss spar urethane on the laminate proved a close match to the celebrity neck finish. I'll rub it down a bit to match the gloss and back burner the neck refinish because this is supposed to be a road warrior. My thumb doesn't care what it looks like s long as it is smooth. Now if only inserting the images was this easy.....I'll try sending them to Damon for help.
Edited by Cavalier 2016-02-22 6:18 PM
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Location: Jet City | Here you go....
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Location: Jet City | 
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Location: Taichung, Taiwan | Wow! You make it look so much easier than it originally sounded.
I'm still trying to locate the higher end epoxy. So far I've only found standard hardware store stuff. |
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Location: undisclosed | The black stripe on the neck isn't for everyone but will save the day in a fall. With a good epoxy you may not need it. It really depends on the angle of the break. A 10-1 length to height scarf using epoxy will hold up to anything. A 6-1 ratio is getting weak, long before you get to a 1-1 butt joint you need to dowel or inlay.. The steep break angle on the mandolin meant reinforcement for peace of mind.
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| If you have trouble finding that, the same type of 2-part epoxy is used in the automotive industry to attach replacement panels. If you take your guitar to the local autobody repair shop, you might be able to talk them into giving you enough to do the repair, or perhaps sell it to you for cheap. Make sure you have time to do the repair when you get it, and know how you are going to clamp it up. There's a nifty clamping block called...BLOKKZ.
http://www.blokkz.com/2-universal-clamping-blocks-ucb-with-2-neopre...
You should be able to find them in woodworking stores. Another great Made in the USA product. |
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Location: Taichung, Taiwan | I hav en't been having any luck finding the stuff, so an autobody shop is a good idea to try. Thanks! |
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Help! Glue Geeks to the rescue! I'm in need of better glue...