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Got My Mind Stuck On Glue

Posted: Fri Oct 14, 2005 6:31 am
by admin
I have a friend who repairs instruments in his spare time and is a crazy glue enthusiast. Rather than waiting for the glue to dry, in nut slots for example, he applies the glue and then uses a hardener in a spray bottle. One quick mist and the glue hardens, or at least appears to, instantly.

My approach is to let the glue dry on its own. The mist leaves a white residue, which is not always becoming. I guess I prefer to stick to the old ways and slot my time accordingly.

My question Curmudge - Is there a difference in the properties of the hardened glue if I wait for it to set versus using the hardening agent? As a follow-up, is it better to let it set without the agent or does it matter.

Finally, are some type of crazy glues to be avoided and, if so, why?

Posted: Fri Oct 14, 2005 7:02 am
by johnhall
My experience with accelerator is that the final strength seems to be diminished and sometimes it causes the glue to foam up in an unattractive manner.

It's also a trip to an almost instant headache from the odor. Nonetheless, there's times when you need that instant hold and it's especially useful when you're using the thicker CYAs to fill up gaps or voids.

Paul also mentioned to me that this stuff ages. I know I've always kept the CYA refrigerated with good results but hadn't thought about the accelerator- wonder if it should be 'fridged too? The otherwise unused butter compartment in my home refrigerator has always been a nice little glue locker, despite what my wife thinks!

One trick to mitigate the accelerator problems is to use a tiny brush to put only a little bit of it on the work first, say on one side of a joint, put the CYA on the other bit and then bring them together.

Posted: Fri Oct 14, 2005 7:15 am
by admin
Thanks John. I was thinking that the strength may be diminished. I might find myself in a bit of a bind if the glue goes in the butter compartment. Then again I guess it was bound to happen sooner or later.

Posted: Fri Oct 14, 2005 7:23 am
by sowhat
Crazy glue? Great idea, never tried, repaired my guitar which was broken with epoxide and seems like it's gonna break again soon (although to be true, after repair its sound got better). Does crazy glue really work better?

Posted: Fri Oct 14, 2005 9:01 am
by johnhall
For repairing what on your guitar? Different gluing problems require different solutions.

Posted: Fri Oct 14, 2005 9:22 am
by jingle_jangle
We gotta can'o'worms here, by cracky, Josh!

Er, Peter, John, Sheena...

The accelerator for CA (CyanoAcrylate) is not a good idea when working on guitars, where finishes are concerned. It does cause foaming and it does reduce strength, and John has theorized that it could contribute to yellowing.

CA works (bonds) anaerobically--in the absence of oxygen. That's why the instructions say "press surfaces together". This activates the molecules and promotes cross-linking and catalyzation. I am not a chemist--the good Doctor could perhaps jump in on this one--but I have used the stuff since 1971 or so, when it cost $90.00 for 2 cc. Back then, Eastman used to advise keeping it in a refrigerator to maintain freshness. I believe this was not only for the cold, but also for the low humidity. Nowadays they don't emphasize this as much, because the material is cheap.

The accelerator for CA is primarily Freon, mixed with some other hydrocarbon compounds. Freon evaporates very quickly. In doing so, it cools by evaporation the area upon which it has been sprayed or otherwise applied. It also blankets the surface of the CA, excluding oxygen.

Accelerator can absorb moisture from the air, and it also breaks down over time (the additives to accelerator are to stabilize it in the bottle and slow down its reaction and decomposition). The moisture bubbles as it evaporates due to heat of the reaction when accelerator is used, and this is what causes the foaming. If the stuff foams excessively, it's not fresh. Ambient light is also a factor in decomposition, hence the brown bottles it comes packaged in.

So if you're gonna store either item, keep it in the fridge for max freshness.

The white film polishes out easily with Scratch-X.

Brands to avoid: ANY kind sold in those tiny tubes in the 7-11 or auto parts stores. Messy, hard to apply, and medoicre quality.

Recommended brands: 3M. Eastman, Satellite City, Pacer Technologies. The first two are available from industrial distributors like R.S. Hughes in the USA, the second pair can be scored at good hobby shops. Also pick up some Micro-Tips which aid application and are disposable and cheap.

Sheena, "Epoxide" is so European! But it's actually more correct, as it describes the family of materials and the derivation of a material, rather than merely labelling it "Epoxy".

I do not recommend epoxies or epoxides for much in guitar repair. I can't really think of any use for it that another type of glue would not work better and more appropriately. Which part of your guitar was broken? Epoxy, unfortunately, is a non-reversible type of fix that has little penetration into wood and depends upon the shear strength of its crosslinked molecules and the strength of the mass of the glue itself, which often amounts to mere film strength. CA is even less reversible, but much. much stronger and even penetrates the wood surface to fill the cells of the wood themselves.

I avoid the term, "Crazy Glue" because it is the best-know household brand here in the USA, and is not the best for professional applications.

I'm sure there will be much more on this sticky topic anon.

Posted: Fri Oct 14, 2005 9:27 am
by sowhat
Belly. In fact, the whole body went into three or four pieces, some silly guy decided my guitar should meet my friends' head. So i need a good advice from people who know since i'm unfortunately bad at it.

Posted: Fri Oct 14, 2005 9:56 am
by jingle_jangle
Ugh. Sounds like a job for the High Priest of Guitar Repair, Martin Luthier...

I guess it does sound better now that it's back together in one piece instead of three or four.

Pictures, possibly?

Advice: Lock it up when "friends" come to visit.

Posted: Fri Oct 14, 2005 10:09 am
by johnhall
So, what did you glue your buddy's head back together with? CA's good for wounds . . .

Posted: Fri Oct 14, 2005 10:16 am
by sowhat
Advice taken, Paul, but i meant it sounds better now than before it met my friend's head.
I'll try and make some pictures of my poor little acoustic and while i'm sure the pictures will maybe cause lots of laughter here must tell this little 'piece of wood' as we call it holds special memories for me so i'd like it to 'live' long and happily for some more years.
John: fortunately, buddy's head was much stronger than my guitar...

Posted: Fri Oct 14, 2005 10:44 am
by johnhall
Don't you mean "unfortunately"?

Posted: Fri Oct 14, 2005 10:45 am
by geschwader
Also, you should be aware that the vapors from most CAs can fog clear plastic parts — perhaps pickguards and TRCs, since they're a lucite-type material. This fogging is not just on the surface. It occurs throughout the thickness of the plastic. It's a good idea to not get too near clear parts when using CA.

Posted: Fri Oct 14, 2005 11:15 am
by sowhat
Well it depends, John. The guy who met my guitar with his head is a really nice bud, the one who hit him was taken away by Kharkov militia, and i bet he'd have needed some CA, but the guitar is now "unbeatable" as my Man suggests. Actually, the biggest problem at the moment is its appearance but i'd like to know what to do in case something comes unstuck - should i go on with epoxy or CA might be a better choice?

Posted: Fri Oct 14, 2005 11:24 am
by jingle_jangle
Fix his head with it and his mind WOULD be "stuck on glue".

Whether to use Epoxy or CA? Depends on the extent of damage, which is why I asked for pics. Sounds like, though, you just want it back together to stay. Not knowing anything about the brand or technical specifications of the epoxy you are using, I'd still have to say" go with the epoxy".

If it's coming apart (sounds like this was all pretty recent), chances are the epoxy was not mixed or applied properly. More care taken with this will yield longer-lasting results.

Posted: Fri Oct 14, 2005 12:28 pm
by johnhall
Paul, given that this is an acoustic more of sentimental value rather than aesthetic beauty, I'd think this is one case where Gorilla Glue might actually be appropriate. Not only would it tend to stick to some of the residual epoxy, it might even foam up to fill some of the gaps that are inevitable with this type of damage.