I was recently talking with a guitar repairman who has been in the business over 20 years and was surprised by the kind of jobs he would regularly use ca glue for. Headstock break repairs, acoustic guitar cracks (tops,backs,sides), and loose brace repair.
I know that most, if not all, luthiers consider ca glue to be an important tool, but was wondering how some of you feel about its use in the above mentioned types of repair. Basically, do you or would you use it for these repairs? Why or why not?
CA is strong but brittle. I wouldn't use it where shear strength is needed.
I like to use it for tight cracks with splints on the inside that are glued with either Titebond or HHG. I'm not comfortable using it for any repairs that need gap filling or anything that may be subject to sheer forces. I wouldn't use it for braces without some experimentation. I think it would hold well initially but I worry about it holding long term. Like Robbie pointed out, it's too brittle for me to trust in a lot of case.
What I seem to use CA for the most is gluing various things to my fingers. It works great for that. I haven't found much of anything that it can't glue securely to my fingers.
I too, am curious about this.
I always keep a pipette full of CA on the bench and usually reach for it several times a day, but never thought about using it for complete breaks or bracing or anything but the tightest of cracks.
Then I read an article last year in which a repair was performed on a Collings slotted headstock that had been broken completely off, as in two pieces, using only CA.
Consider mind blown!
I'd love to learn more/better techniques for it's use.
The savings in time could be passed along to the customer and potentially reel in those marginal jobs that would be cost prohibitive using traditional methods.
I used to be an anti-CA nazi of sorts not wanting to use the stuff for Lutherie. But through the years I have found some things that it's good for:
Securing a nut
closing a cut in the shop (don't ever use accelerator..... ask me how I know this....)
sometimes for regluing binding, very small reglues
That's about it for now....
For cracks and cleats it's HHG or Titebond Original (TO)
headstock repairs HHG
brace repairs HHG or TO
bracing, bridge plates, bridges on new builds HHG
Necks to body HHG except for bolt-on necks, of course... ;)
fret board extensions I like a small puddle of TO or HHG
As you can see I don't use CA for much these days but I am trying.....
By the way time for one of my stupid stories.... :)
I used to be an instructor pilot for radio controlled helicopters and airplanes. We had an every Thursday evening thing where we taught beginners.
One student stuck his hand in a prop and had some very bad open cuts and was bleeding profusely. Another instructor and I had just read the same article in a magazine about using CA for closing cuts.
So we treated this guy and then drove him to the hospital. The hospital staff said that we did the right thing, he was on warfarin and had very thin blood and could have kept bleeding had we not intervened.
All was well and about a month later the same guy showed up with a huge, nasty burned spot on his forehead.... I asked him what happened and he told me that while under a car removing a muffler it fell and cut his head. He remembered what we did with the CA and applied it to his head....
Then, sadly he also sprayed accelerator on his head and burned the hell out of himself....
Sorry for digressing, I think of this story when ever someone brings up CA...
CA's been around for medical use for a few decades but I think the formula is a bit difference since the stuff we use can cause skin irritation and may heat enough to burn us if too much is used.
BTW, are any of you aware that CA and cotton balls don't mix and that we should be careful of cotton clothing when we use CA? A very quick, hot and smoky reaction can result when CA gets on cotton and I think wool as well.
I've used CA for cuts for several years. I've switched to the generic version of Dermabond as it is a bit more flexible and doesn't loose adhesion as quickly. Make sure to wash the wound first and pinch it tightly closed. A Pentagon study during the Vietnamese war found CA to be better than sutures as suture punctures provide a point-of-entry for bacteria.
I've also been using it on my fingertips on my fretting hand whenever a callus starts peeling. I put it on my son's fingertips when he got his first guitar and it really helped.
They now make a spray for abrasions.
CA works with the stuff the product sheets say it works with - I use it everyday for something or other and find it indispensable and remarkably time saving.
Prime example - use it as a backup glue for Titebond - headstock breaks which have shattered the surrounding timber are a good example - I use Titebond to do the heavy lifting and use syringes to work the glue in as best can be done - the long open time is great for getting the needles in exactly where they need to go and working the joint close and clamping is also easy because of the open time. To finish off after the Titebond has hardened up I then lather the area with thin/medium CA to wick into the remaining blind cracks and fractures to both fill and stabilize the join in prep for sanding and lacquer etc.
Gluing frets in is the other use which I wouldn't be without.
Million other uses. Good stuff.
If I remember correctly, when CA glue was first introduced, it was said to have been invented specifically for the veterinarian industry to close wounds on animals.
That is all I have got.
I use if for putting on nuts and fret end glueing and a few other things too.
Kevin Gallagher once said he built an entire guitar with CA as the only glue. Said 10 years later it was fine.
Thanks to everybody that weighed in.
Hesh, you're detailed replies are always informative and always appreciated.
Rusty, I'd never heard of using CA as a backup for titebond on a headstock break. I'll definitely file that one away.
CA's best attribute is that it has incredible capillary action, the ability to wick it's self into the tightest of places. It is easy to apply, can give good results and it's fast. This ability is a tempting solution for many repairs but one should keep in mind that CA is mostly a non-reversible glue. Short of finish attacking solvent or mechanical removal, there is no way to get rid of it once it's applied. I have done enough repairs now to have had to undo a few repairs that I did and have become more sensitive to the notion of "do no harm", or put another way, use no irreversible glue. It has it uses though and I keep a fresh bottle and pipettes at the ready.
Hot hide glue is always my first choice for any repair jobs where I think it will be enduring. Original Titebond comes out to, if hide glue is iffy because of a grungy joint or the job needs to more open time.
Things I use CA for have included: gluing frets, gluing shims onto nuts (I used to fill nuts slots with CA and bone dust but quit doing that and just shim them and re-cut slots now. Luthier's Mercantile sells .020" bone shims now, CA is great for attaching them. I don't use CA to glue the nut down and prefer a few small dots of Titebond for that), inlay work, including filling around the inlay and is also useful for stabilizing vintage inlay work. It is handy for attaching pads to clamps and other seat of the pants jig creations. CA is good for helping worried/ split screw holes, especially in softer woods.
I have used CA on occasion with a badly shattered head stock, as Rusty suggests, using it as a secondary glue. I have also had good results though, using hot hide glue with bad fractures that is watery thin. I heat everything first with a Red lamp, apply the thin hide glue and then hit it with compressed air in a short blast. I repeat this several times, working the joint open and closed.
I have been doing a number of Pegheds, geared violin tuner installations in banjos. They install with a two degree reamed hole and have tiny threads to screw then in. A lot of vintage banjo necks are made with Spanish Ceder or other soft woods that won't readily hold the tiny threads. Lace the prepared hole with CA and it will toughen the wood and get the threads to bite.
I recently glued a patch onto my belt sander dust bag with CA to patch a hole. I'm sure I could think of a bunch more stuff if I sat here long enough. It is not a fix all and does not have many years of use for a track record. Will it break down over time like other plastics? No one knows. How will it hold up in a hot car? Not as good as hide glue. Is it reversible? Mostly not. It should only be considered for use where reversibility doesn't matter. Instrument repair is stewardship, keep this in mind when your thinking about short cuts.