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Is there a fix for this? I seem to recall if you spray x substance on, you can remeld the nitro…?

I remembered this from Frets.com

http://www.frets.com/FretsPages/Luthier ... ator1.html

Pretty amazing results!

M

It would be useful to have some more details of what you are working on. New finish or old?

I crazed a nitro finish once due to drawing in freezing air into the shop. I sprayed several coats of straight lacquer thinner and it softened the finish enough to heal the cracks. This was a super thick finish consisting of about 25 coats on a large desk project.

George Grotz, in his book "The Furniture Doctor" Talks about rebrushing lacquer furniture, which can work well on furniture that is built from thicker stock than guitars. Depending on why the finish checked /crazed it might be possible to do this and not have it check/craze again. Instrument lacquers generally have more plasticizers than typical furniture lacquer, so if it was originally sprayed with furniture lacquer it may check/craze again. Some catalyzed finishes cross link and may not react well to being re-amalgamated using solvents.
It's probably worth trying if the alternative is stripping and refinishing anyway.

Keep in mind that nitro is not a finish for the ages. It's the little brother to a high explosive, and one molecule out of every six or so is unstable. All it takes is some time, or a bit of UV light and it will convert into water, CO2, and an oxide of nitrogen, which then reacts with water vapor to form nitric acid. If you remove one brick out of every six from a wall, what happens to the wall? Over time nitro shrinks and cracks, and the more of it there is the quicker this happens: think celluloid pickguards and binding, and nitrocellulose movie film.

There are solvent based 'amalgamators' that will penetrate into the checks and melt everything together. This doesn't make the finish any less unstable in the long run. Using something like that on any instrument that could be in any way considered 'vintage' will hurt the resale value down the road. Remember that nobody thought about the 'vintage value' of those old Martins and Fenders and Les Pauls back when they built them. They used a finish that was ultimately ephemeral because they were focused on mass production and the short term bottom line, not on making a 'work of art'.

I've had to use Blush Eraser a few times before and I believe that works by re-melting the Nitro.

Thanks…

Let us know how it works out. I've got one that I've been debating something like that also. However, it's very fine and even and only visible at certain angles. It actually looks pretty cool LOL

Not sure exactly how, but I think it happened when I left it in the garage when I was reworking the shop and it got close to freezing...

Pat

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Pat

This happened from culture shock. On the ‘nicest’ guitar I’ve ever made. I’m trying to convince him to just leave it be.