CA glue repair gone wrong

Hoof Hearted · #1 10-24-2021, 01:30 PM

After watching people do it on Youtube, I've used CA glue several times to fill dings in my guitars. It's always worked out well and the repair has been completely invisible after i've sanded and polished it. Last month I bought a Santa Cruz guitar with a large ding in the rosewood back. After my previous experience I thought it would be simple to fix. On this guitar however, the CA glue has reacted and made the surrounding lacquer much lighter. I've sanded out the glue a couple of times and used a wood dye to darken the wood before trying a different CA glue. Each time though, the CA glue has touched the surrounding lacquer and lightened that. The damaged area is now considerably larger than the original ding. Can anyone give me an idea how to stop the lacquer from lightening when I apply the CA glue?

Misifus · #2 10-24-2021, 02:26 PM

It seems clear to me that CA glue might not be the best way to fix your guitar. If you think about it, guitars are not finished with that stuff. I don’t know which finish Santa Cruz would have used in your model, but if you contact them, they should be able to give you some good advice.

dnf777 · #3 10-24-2021, 03:01 PM

Sounds like a water-based finish that some makers have gone to in order to comply with strict environmental regs. Might contact SCGC and see if they can help out with either advice or a repair.

Hoof Hearted · #4 10-25-2021, 04:02 PM

I've emailed Santa Cruz and asked for their advice.

There's quite a number of Youtube clips showing CA glue repairs, some of them by professional luthiers. Like I said, i've done this type of repair several times with excellent results. The only time it didn't quite work out was on my Lowden F50 when the underlying wood went a bit darker. It was only a tiny repair though. So it scarcely showed.

tadol · #5 10-25-2021, 07:44 PM

Santa Cruz uses nitrocellulose lacquer, and is best repaired with lacquer drop filling, or not at all. Never saw a little dimple that made a Santa Cruz sound bad -

davidd · #6 10-26-2021, 08:31 AM

Why aren't you using lacquer?

Bluesdale · #7 10-26-2021, 09:03 AM

I use lacquer on lacquer, and CA on poly only.

redir · #8 10-26-2021, 09:55 AM

What CA glue are you using and are you using an accelerator?

Nitro is best to repair nitro with but CA should still work.

phavriluk · #9 10-26-2021, 02:52 PM

I think OP might be in over his head. And a Santa Cruz guitar ain't a piece to practice on. The experienced luthiers here have worked for thousands of hours each to refine their skills. A couple paragraphs of postings cannot bring someone up to speed.

My suggestion is that OP stops and consults a professional who can do an in-person evaluation. OP started with one problem and wound up with two. No use trying for three.

Fathand · #10 10-26-2021, 07:00 PM

So you've done it 3 times and it got worse every time. That means try something different. Obviously the CA you are using us not compatible with the finish on your guitar. Maybe you have expired CA? Maybe the guitar is finished in something other than your previous guitars or has been polished with silicone or otherwise contaminated? Maybe it was refinished at some point?

Find out what finish is on the guitar from the manufacturer and go from there. Get a can of aerosol nitro lacquer or shellac at home depot or Stew Mac if that's what's on the guitar and try it on a small obscure area before attempting a big fix.