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Location: Hawaii | Aloha all you BFLG gurus,
I'm wondering if anyone has a preference on which epoxy to use to reglue a top that is separating from the bowl?
I have a 1985 Legend 12-String (#1756) that I have owned and loved since I bought it new (as a Christmas gift to myself) back in 85'. The top is separating from the bowl just behind the preamp/eq - about 8 - 10 inches long. Its actually the binding separating from the bowl, and NOT the wood top from the binding.
If I could afford to send it to the factory for repair I would. But due to budgeting, that's out of the question.
John from MS said to use epoxy, but didn't specify any particular brand or other characteristic.
What do you all think (which epoxy)? |
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Location: Lake Forest, CA | Generally speaking, epoxy is epoxy unless you're talking about aerospace-grade epoxies like Hysol.
Hardware store or hobby-grade epoxies have the strength to hold the bindings in place.
Again, generally speaking, the faster the epoxy cures the more flexible it is when cured.
So, 60-minute epoxy will be harder, i.e.: more brittle than 5-minute epoxy.
The trick with epoxy is getting it down inside a glue joint like what you're describing. First, you have to mix the two parts, then you have to have a way to inject it or use a tool such as a tooth pick to apply it.
Another option would be to use cyanoacrylate, or CA. (super glue)
I've used CA to glue loose rosettes, fretboard bindings and even braces. If you decide to use CA, I would recommend using a hobby-grade CA like ZAP by Pacer Technologies.
Hobby-grade CA glues come in different viscosities --thin, medium, thick and gel.
Generally speaking, the thinner the CA, the faster it dries. You can also use an accelerator with CA that forces the glue to cure more quickly. (a few seconds instead of a few minutes)
If I were going to attempt this type of repair, I would use either thin or medium CA instead of epoxy. Pics of the area to be repaired would help.
With thin CA, you can hold the binding in place and wick the glue into the joint, holding it in place until the glue has cured. The danger here is that the wicking action of the glue is so good that if you apply too much glue it will wick out between your fingers and the outside of the binding.
With medium CA, you would hold the joint open slightly and wick the glue in along the edge of the binding, then hold the joint together until it dries. Medium will still wick out, just not as much as the thin. |
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Location: Bristol England | Dan,
I've commented on your in depth knowledge of glues before and once again you have shown it extends way beyond just wood glues.
I always find your posts most informative and was awaiting your reply on this call for help.
I knew you wouldn't let me down and you haven't.
James. |
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Location: Lake Forest, CA | Thanks for the kind words, James.
Another hobby/avocation of mine for the last 35 years or so has been designing, building and flying R/C model airplanes.
That hobby has a lot in common with all guitars, in general and Ovation guitars, specifically, such as the use of spruce, plywood, plastic and fiberglass and the ability to bond all of these materials together.
Modern luthiers have recently started using the same glues that we've been using for years in model airplane construction/repair and for the same reasons --low cost, ease of use and availability.
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Location: Boise, Idaho | Dan, if you could come up with a relatively easy way to fill and repair finish cracks, particularly on Ovations, you may be very popular. (Not that you aren't already.) |
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Location: Hawaii | Aloha Dan, Appreciate your expertise. I added some pics from my dropbox. Hope they work. Since I have very little if any experience doing a repair on a guitar, I'm guessing I will need a slower curing time to allow me enough time to apply the epoxy or CA, set the binding in place, apply clamps or tape, etc, before the glue sets. https://www.dropbox.com/s/mlp9u68bq1y3h96/20130906_144706.jpg?m https://www.dropbox.com/s/lc4g4as5ljvrazt/20130906_144721.jpg?m https://www.dropbox.com/s/2y3ncxmuqagoacw/20130906_144758.jpg?m https://www.dropbox.com/s/8atczph197l3lwc/20130906_144650.jpg |
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Location: Boise, Idaho | That doesn't look too bad. My suggestion is to figure out a good clamping device and try it out to make sure it will close the gap and hold it before the glue dries. Also, practice so that you can close the gap quickly enough that the glue won't dry before you get the clamps tight. It might be as simple as adding weight to the top or the bowl, but I've worked on way too many projects where I ran out of hands because I hadn't planned on having to hold 3 things at one time. |
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Location: Hawaii | I know I can do the repair. I'm more concerned about the timing because I'll probably concentrate on covering every inch of the separation with the adhesive and make sure the parts line up correctly before I clamp down. Knowing me, this will take time - even if I practice before I actually do. 10 seconds, or even 30 seconds with a medium CA like ZAP doesn't seem like very much time. The main reason I'm considering using an epoxy with a longer cure time. On the other hand, it sounds like toe CA's can seep into the tighter areas better than the epoxies. Hmmmmmm, which way to go . . . . . .?
Any other suggestions on clamping. I'm thinking of just using tape since it looks like it doesn't need much pressure to hold the parts together. I can easily press them together with my fingers right now - and that;s with the strings still on applying tension. I don't have any large C clamps or a rig - though I guess I could use my son's weights. |
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Location: Lake Forest, CA | Mark in Boise - 2013-09-06 4:37 PM
Dan, if you could come up with a relatively easy way to fill and repair finish cracks, particularly on Ovations, you may be very popular. (Not that you aren't already.)
Thanks, Mark.
There's always thin CA. It wicks into cracks very easily.
The trick to keeping thin CA from going all over the place is to use a capillary tube and gravity.You don't want to tip the bottle all the way upside-down. If you do that, the glue will come gushing out. You only want to tip it enough so you can control the flow of glue. That means, tipping the work piece so you can control how fast the glue comes out. Below are a few pics.
1) Thin ZAP with one version of a tip that has a built-in capillary tube.
2) Thin ZAP with Z-End tip. Z-Ends come with capillary tube.
3) A small section of tube is cut and inserted into end of Z-End.
4) Sometimes, when I need to reach in deeply, I make a really long capillary tube tip. :D On medium CA (Zap-A-Gap) I use the Z-End tip without the capillary tube. 
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Location: Lake Forest, CA | datwyl01 - 2013-09-07 3:58 AM Aloha Dan, Appreciate your expertise. I added some pics from my dropbox. Hope they work. Since I have very little if any experience doing a repair on a guitar, I'm guessing I will need a slower curing time to allow me enough time to apply the epoxy or CA, set the binding in place, apply clamps or tape, etc, before the glue sets. In looking at your pics, I can see your quandry about which glue to use. Does the split extend all the way around the bowl from the amp to the lower treble bout? In the pics, I looks like two splits. One that goes from the amp to the bottom strap button, then another that goes from the bottom strap button to the lower treble bout. Also, the pics almost look like it's the top has separated from the kerfing inside the bowl. If that's the case, then I would use slow-set epoxy. (at least 30-minute or even 60-minute) I would use some dental syringes with a thin tip to inject the epoxy into the glue joint. (Monoject 412 - May be available at your local hobby store --that's where I got mine) You would mix up the epoxy in a clean 1-oz. mixing cup, (Also available at your local hobby store) then pour it into the syringe and insert the plunger and hold the tip up to push all the air out until the glue starts to ooze out the tip. (clean up with isopropyl or denatured alcohol) Next, inject the glue and use some luthier binding tape or equally strong masking tape to pull the bowl back against the top/kerfing/binding. You want to use as little glue as possible and inject it as far down into the joint as you can so that none is squeezed out when you pull the joint back together. If any is squeezed out, it can be completely cleaned up using either isopropyl or denatured alcohol. I would try to fix all the splits in one sitting instead of trying to break it up into separate sessions. |
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Location: Hawaii | Its actually 2 separate areas. The first starts just behind the amp and extends around to just behind the upper bowl area. The second is below the strap button.
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Location: Lake Forest, CA | datwyl01 - 2013-09-07 2:32 PM
Its actually 2 separate areas. The first starts just behind the amp and extends around to just behind the upper bowl area. The second is below the strap button.
That's what it looked like in the pics.
I would use epoxy for this repair instead of CA.
Is the kerfing pulled away from the bowl or is the binding/top separated from the kerfing?
It looks like the kerfing is pulled away from the bowl. |
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Location: Hawaii | Ummmm. I'm probably using wrong terminology.
The white plastic band along withe the wood top and black pin striping around the edge are still intact.
The white plastic is what's separating from the bowl. |
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Location: Lake Forest, CA | datwyl01 - 2013-09-07 2:46 PM
Ummmm. I'm probably using wrong terminology.
The white plastic band along withe the wood top and black pin striping around the edge are still intact.
The white plastic is what's separating from the bowl. That's okay. It would probably help if you were able to see how Ovation bodies are built.  Go to this thread and watch the video of how the bowls are built. The section that describes the bowls starts at the 10:00-minute mark and runs to the 17:00-minute mark. (See: Wow! In depth factory tour!) Watching this will help you understand exactly which glue joints have popped loose which will help you understand how you need to glue them back together. If you still have any questions after watching the video, feel free to ask. |
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Location: Hawaii | Very interesting video. Gives me a greater appreciation of what went into making my guitar.
So now that I have a better understanding of terminology, I'll go back and take a closer look to see exactly what's going on. I'll get back to you in a day or two.
Do any of you ever get caught up in having to explain to your better half what all the fuss is about when it comes to properly repairing your Ovation, or any other quality product for that matter? My wife just doesn't understand why it's so important to me to fix my guitar. |
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Location: Hawaii | I'm back. So I took a closer look at the sparations. I did a light test, figuring if the top/binding was separating from the bowl, light would come through the crack when applied to the inside of the bowl. Such was not the case. As I pressed down on the separation I could see, barely, the black kerfing also moving up and down. The bowl is not flush with the binding at the separation.
Dan, you are right on the money about the kerfing having pulled away from the bowl. And you determined this just by looking at the pics.
So know I have to figure out how to get the glue down between the bowl and kerfing, and be able to aplly pressure from bothe inside and out long enough for it to set.
Am I still looking at using epoxy or am I back to CA? Advantage of CA - quicker cure time means I could probably get away with using my hand to apply pressure for a few seconds versus minutes. Tape may also work. Advantage to epoxy - longer working time. |
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Location: Lake Forest, CA | datwyl01 - 2013-09-08 9:24 PM
Dan, you are right on the money about the kerfing having pulled away from the bowl. And you determined this just by looking at the pics.
So know I have to figure out how to get the glue down between the bowl and kerfing, and be able to aplly pressure from bothe inside and out long enough for it to set.
Am I still looking at using epoxy or am I back to CA? Advantage of CA - quicker cure time means I could probably get away with using my hand to apply pressure for a few seconds versus minutes. Tape may also work. Advantage to epoxy - longer working time.
Actually, the kerfing repair would be easier than if the top/binding separated from the kerfing.
Yes, I would still use epoxy rather than CA, mainly because of the length of the split.
You are correct that you could hold the joint together with hand pressure, but you would get into a situation where part of the split is glued and another part is not, which would cause a ripple in the seam. (Ewww...)
You want to have the entire seam pressed together all at once so that it is smoothly joined all the way around.
Although it would be more difficult, you could apply the glue to the inside of the kerfing/bowl joint from the inside using a syringe. (imagine caulking a bathtub-to-wall seam)The benefit to this is that the outside of the glue joint would be neater and you'd be putting more glue where it will do the most good, i.e.: between the bowl and kerfing. Also, the tape won't stick as well if there is uncured epoxy along the joint.
If you use a Monoject syringe you can run the tip along the inside of the kerfing/bowl joint and inject the glue into the seam.
Then, use the binding tape to pull the top and bowl joint together and let the epoxy dry.
Naturally, when gluing this type of repair, you'd want to perform it dry, i.e.: without glue so you can assess how well the tape will pull the joint together and get an idea of what you'll need to do and how much time you'll need to do it. In this case, I would use a slower setting epoxy rather than a faster-setting one. I would not use anything that sets faster than 30-minutes. 60-minutes would be better. You want to give yourself as much working time as possible. Then, once the glue joint is exactly as you want it, you can just set it aside until the glue is dry.
You would also want to use the luthier's trick of tearing off as many pieces of tape as you're going to need beforehand and sticking them to the corner of your workbench so that you just have to grab the pieces of tape and apply them. This way you can keep one hand on the work and use the other to grab the tape rather than having to take both hands off the work while you tear the tape off the roll. (See: Binding tape photo) You could also use binding rubber if you're not happy with how the tape is working. The main thing is that you'll need to pull the top/binding down and pull the bowl inward so it's tight against the kerfing.
Edited by DanSavage 2013-09-09 1:44 AM
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Location: Hawaii | Got it. Now I feel I'm armed with enough instructions thanks to you Dan. Need to go and purchase all my supplies - epoxy, tape, new strings, syringe, etc. In the meantime, I will begin cleaning the joints and make some practice runs. I'll let you know how it turns out. Wish me luck. |
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Location: Boise, Idaho | Dan gave you thorough advice on the guitar repair. The only question he didn't answer was the question about explaining the fuss to your wife. I have much more experience there (36 years) than with guitar repairs, so I'll take that one: don't try. She'll make a fuss over something you won't be able to understand and vice versa. We each have our obsessions and we can't be expected to share all of them. Enjoy what you enjoy and let her do the same.
Good luck with the guitar repair. Looking forward to the "after" pics. Some "during" pics would be nice, too. |
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Location: Lake Forest, CA | I'm looking forward to reading about your results.
Luck! |
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Location: Hawaii | Aloha all,
So it's been almost 2 years since asking the question about glues and sharing pics of my ovation with the top separating from the bowl. Well, I finally got around to tackling the repair over the last couple of days.
I went with using T88 epoxy with a 1 hour gel time and 24-36 hour cure. Used, of all things, 4 automotive tie straps to hold everything in place. It worked out pretty good. After cleaning up residue, and checking the joint, there is no play or separation. Some cosmetic blemish along the edge - basically took of some of the brown finish on the bowl while cleaning the residue.
Working to complete the set up to see how the guitar sounds. I took pics along the way and will post asap. Thanks for all your input. |
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Location: Hawaii | Attaching some photos from my dropbox:
After prepping the surfaces (sanding, scrapping, cleaning with rubbing alcohol, blowing compressed air), I mixed 1:1 T-88 epoxy in a small cup and scooped it into a dental syringe (monojet 12), and applied it generously to the entire area. I used a small sculptor's knife to pull the bowl away from the kerfling to get the epoxy into the furthest points.
Prepped surfaces (from the outside)
https://www.dropbox.com/s/fynwmbkwgb1fuli/2015-06-23%2017.44.59.jpg?...
https://www.dropbox.com/s/eem4ye8vj3gpgxg/2015-06-23%2017.45.33.jpg?...
https://www.dropbox.com/s/a5f167eupaxcfix/2015-06-23%2017.45.37.jpg?...
https://www.dropbox.com/s/c4yf4v6sjre28xy/2015-06-23%2017.45.49.jpg?...
https://www.dropbox.com/s/v9uvuxy2bh3p5zm/2015-06-23%2017.46.18.jpg?...
https://www.dropbox.com/s/jntrms4ykwmxivj/2015-06-23%2017.46.21.jpg?...
https://www.dropbox.com/s/ad78bar5vo2vmrm/2015-06-23%2017.46.34.jpg?...
Using T-88 epoxy
https://www.dropbox.com/s/jp6u2o7bucyhele/2015-06-23%2018.27.27.jpg?...
https://www.dropbox.com/s/1220k2lrz9kkm6q/2015-06-23%2018.27.40.jpg?...
https://www.dropbox.com/s/xupgg471sp78r3l/2015-06-23%2018.27.34.jpg?...
Clamping it all down using tie-down ratchets (LoL): Tight enough to hold it all together and close the gap, but not too tight that it would crack the bowl or top. Total of 4 straps.
https://www.dropbox.com/s/jw7x7xo8cl36tvv/2015-06-23%2018.45.23.jpg?...
https://www.dropbox.com/s/t62ex3vcse1fcz3/2015-06-23%2018.45.32.jpg?...
https://www.dropbox.com/s/66pfi5479of3an9/2015-06-23%2018.45.45.jpg?...
I removed the straps after 24 hours of cure time. Repaired area before cleaning it up:
https://www.dropbox.com/s/acnjtaiptr2oe7z/2015-06-26%2013.04.51.jpg?...
https://www.dropbox.com/s/b6o1aist9yli0hq/2015-06-26%2013.04.57.jpg?...
https://www.dropbox.com/s/uii1ujnex0l5rai/2015-06-26%2013.05.08.jpg?...
(yes there is epoxy in there)
After some scrapping and light sanding to remove leftover residue. The black edges are a result of sanding of some of the brown finish.
https://www.dropbox.com/s/fzjmk0ah9ayfye7/2015-06-26%2018.51.31.jpg?...
https://www.dropbox.com/s/4a9fs6v31fsfig3/2015-06-26%2018.51.48.jpg?...
https://www.dropbox.com/s/78tqjzfz06amaf4/2015-06-26%2018.52.02.jpg?...
https://www.dropbox.com/s/84l8qdhi02pic6b/2015-06-26%2018.52.09.jpg?...
Cleaned up and reinstalled the electronics. Had some automotive CRC electronics cleaner laying around.
https://www.dropbox.com/s/lg1z5upsnt7z1wd/2015-06-26%2019.12.23.jpg?...
All in all, it wasn't that hard of a process. But, only time will tell. Should be setting up the guitar tomorrow and making adjustments to the action and truss bar. Wish me luck.
Thank to everyone for their input 2 years ago. Sorry for the long delay.
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Location: Lake Forest, CA | datwyl01 - 2015-06-29 1:49 AM
All in all, it wasn't that hard of a process. But, only time will tell. Should be setting up the guitar tomorrow and making adjustments to the action and truss bar. Wish me luck.
Thank to everyone for their input 2 years ago. Sorry for the long delay.
Thanks for the update. I'm glad everything worked out.
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Location: Yokohama, Japan | Looking good, datwyl01! Please post pics of the completed project when you cross the finish line! Thanks for sharing your journey! |
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Glue (epoxy) Preference
