That number was pulled out of my ear. I know it's a high number, but I don't know how many it is.
When I did the finish on my towers, I read the how to, and for nice guitars I think they did 6 to 12 layers. But you have to dry half a day and sand between each.
Piano finish turned out much harder to do than the instructions implied. Big fan of satin now. Probably why Axiom adds a 25% up fee for Piano over satin - sanding is tedious job of perfection. Hell, maybe they do go up to 20 layers. That would explain a long lead time.
