This question leads me to a question that I intended to ask in a few days about finishing the "lute" (I use quotes as most of you don't agree that the flat back can be called a lute) that I'm making. On the various other stringed instruments I've made I've used several different finishes. Clear Tung oil with an overlay of Poly, a mix of Poly and Tung oil, a stain with a Poly overcoat. I have read this thread in its entirety, and noted the egg whites homemade varnish. Not all new developments are bad. One does want to seal the wood a bit, but one also wants to give it a bit of moisture. I like a "wipe on" finish, it can be applied better than a brushed on or sprayed finish.
I just found a Minwax wipe-on Poly, and I'm going to test it on some scrap - both with an undercoat of pure Tung oil and as a solo finish. On my harps and psalteries I've found that feeding the wood with pure Tung oil, and coating the outside surfaces with a hard coat (several different Poly formulations) works well, and I leave the internals open to allow them to react to the environment, and so far the differential between the surfaces hasn't caused a problem. Can any one tell me the difference in the nature of a varnish, a shellac, or a modern Poly? I've worked with wood for a long time but yet don't know which is what. In my opinion a varnish is a combination finish, with elements (such as that egg white, or my Tung oil) that feed the wood - and a hardener that makes a protective surface. And a shellac is just a surface hardener and protective coat. Given that I think a combination of the modern Poly with an oil of choice adds up to a varnish, whether applied separately or as an amalgam. I believe in oiling wood and letting it breath, but an instrument also needs a bit of protection from immediate change. I hope I said that clearly, if I didn't please try to read the intent. I am more interested in making this "lute" have a sound character than having it as a "thing of beauty". Suggestions are welcome. The soundboard is Sitka Spruce, often used for harps where the string tension is a direct pull and the board will "belly". The sides and back are Aspen, with a Walnut veneer for appearance. Those I can finish any way I want as the oil won't get through the veneer. And I do know not to put a hard finish on the fingerboard, I've made other fingerboard instruments. Finally, as to the wear point on the sound board, I've got that on the mountain dulcimer. And I've had finger wear on a number of guitars. Unless it starts to get deep into the wood you aren't affecting the sound. I would use the "spit" solution to clean it, then wipe on a bit of hard finish to protect it. As someone said, wear shows the instrument is being used, and that is what instruments are for. Try to keep the nail on that right little finger short so that your natural oils and skin make a small amount of wear rather than having the surface worn by the hard nail. Best, Jon
