Official Luthiers Forum!

Great fix Alain!!!
I know by your first post that you wanted to tackle the job !
Now you've fixed it to the owners delight and learned allot!


CA. in a finish crack-be careful!
it can do more harm than good SOMETIMES!!

Mike

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Mike Collins

Thanks Mike!

And thanks again for the tip!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

I have touched up lacquer with CA and it can work great. I like to use Frank Ford's idea for a razor blade with a turned hook as a mini-scraper for leveling the CA. Sanding CA drop fills is problematic as the CA tends to be as hard or harder than lacquer, making leveling difficult and resulting in oversanding of the adjacent lacquer.

JRE, my point about the shellac was not that it will be incompatible, but that it will act as a sealer which MAY have limited the amount of burn-in on the drop fill. The fact that you can still see the crack on the repair may be evidence of a lack of burn-in.

I have also been following the advice to never use CA on lacquer. I thought it would make the universe implode or something if you did that. So, I'm very interested to hear of people doing it successfully. But now I don't know what to think. I guess I'll have to experiment on junk guitars, but it would be great if some others could chime in here with their experiences.

(If the universe implodes, don't blame me.)

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Too Late! It's YOUR fault, Todd!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

you're dead right, i rarely knowingly under-quote, but i do sometimes quote for the time it should take to do a job - not what i know it may well take me - i get a bit over perfectionist sometimes...probably a result of drooling at the guitars/ repairs on this forum!

Truthful answers are the best way to win a customer over I think - my attitude is always 'how would i want to be treated', which works pretty well.

all the best, and well done again on that repair

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www.theguitarrepairworkshop.com

Thanks Curtis!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Todd,

Repairing finishes with CA has to be done carefully as the CA can etch into a finish. Inadvertent drops or splashes of CA will leave permanent marks. And if a run gets away from you, there goes the farm. But there are some advantages. CA can run into finish cracks and under loose flakes and bond them almost invisibly. Also, if you have a large ding, a CA fill has much less shrinkage than a lacquer drop fill so you don't have to let the fill cure for days or weeks prior to leveling.

The problem in the past with CA repairs was leveling them to the adjacent lacquer surface. Cured CA is so hard that as you sand it, the lacquer on either side gets sanded more so you end up with a dimple in the lacquer surrounding a peak of CA. But this problem is largely mitigated by FF's razor blade technique. Turn a hook on one and it works as a tiny scraper. Place Scotch tape on the outside edges of the razor blade to keep it from scratching the lacquer. It's a little tricky to turn a hook on a razor blade, but once you figure that out you're golden.

Most repairmen I know have been using CA for years for this kind of work. But they used to be reluctant to admit it as there was a lot of bias against CA. Builders might want to check it out.

Thanks, Barry!

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/