Leslie W Bartlett wrote: > Can one use that epoxy to fill cracks in an old soundboard? > > Leslie ----------------------------------- Leslie, I have no idea what epoxy was being referred to in the original post. We do use a very thin epoxy from time to time, but it hardly cures in 30 minutes -- 24 hours is more like it. I think that is generally true with most water thin epoxies. At least those that are generally available. (Epoxies of this type are usually called "coating" epoxies, by the way. System Three makes the one we use. I think West System also has one.) And, yes, epoxy can be used to repair cracks in soundboards. Although we don't use coating epoxies to do it. We use our usual slow setting shop epoxy. Right now we're back to the WEST brand. Remember that the repair of any soundboard crack is of cosmetic value only. It does not restore crown and it does not restore the acoustic function of the soundboard except, possibly, in a very minor and very temporary way. So any one method of cosmetically repairing the crack is as good as any other. I stopped shimming old soundboards years ago, except in very special cases. Put some color in the epoxy -- use powdered fresco colors -- and flow it into the crack. We used a plastic dental syringe to lay a bead right along the top of the crack. If the crack is very small, use a fairly thin mixture. If the crack is fairly wide, you might need to thicken it up a bit. You can use the wood dust from your sanding machine. Or ground up cotton fiber. With a very small crack you want the epoxy to be able to wick its way all the way through the crack and bead up along the bottom. With more open cracks, you may need to force the epoxy through with a small spatula. After it has had some time to soak in, you may need to apply a second or a third bead. The advantage of using very slow setting material is that it has plenty of time to wick and soak into the crack. You need to be sure you get the material all the way through the board. If you're wise, you'll be back under there just before the epoxy turns hard cleaning up the bottom. If you're not, you'll learn the hard way that it's MUCH easier to wipe off the excess than it is trying to scrape it off once its hard. I would normally do this before I scraped the original finish off of the board. And I would put a strip of masking tape along both sides of the crack to make clean-up easier. Del
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