View Full Version : Which finish to spray?
I know this topic has been tossed around many times, and I have read most of the responses given, but I am still unclear as to which finish is preferred for spray application, what type of finish will give me the most flexible, acoustically superior finish? Lets hear it.
Well, it really depends on your capabilities and skill. You CAN spray most finishes if you are sufficiently skillful.##Lacquer is probably the easiest to spray and get decent results. You can spray oil varnish but it is more tricky than lacquer. It is also possible to spray spirit varnish (shellac) but again, it takes some skill and experience. Lacquer is by far the most forgiving sprayed finish.
Flexibility and acoustic transparency usually come from very thin finishes. Getting a good appearance while maintaining a thin finish is not as easy as most folks imagine before they try. Possibly your best bet in this regard would be polyurethane. It stays flexible and is pretty tough. It is NOT the finish of choice for most makers, it does not patch or repair particularly well. Many Givens mandolins were finished with polyurethane, so it is not entirely out of the question, but if repairability is of concern you would do better considering other finishes.
[QUOTE] Many Givens mandolins were finished with polyurethane.
Wow, I wonder if thats whats on mine. (circa 79) I'll tell ya when it gets hot and ya get a bit sweaty the neck can get a tad sticky feeling which would make sense with Polyurethane. Then again it did the white blotchy thing when I wiped it down with a damp cloth to clean the built up gunk off the top which made me think varnish. (and scared me bad!) Is their a test that would give me a better idea without damaging it? I've sprayed a lot of lacquer and Poly in my life and it just doesn't seem like lacquer to me.
Mandolooter, that one sounds more like an oil varnish to me. However, once time and sweat and heat and lots of playing and who knows what else comes into contact with a finish it can exibit unusual characteristics at times. Just look at some of the older guitars where the player's arm rests on the top. The finish can be compromised considerably, no longer looking or acting like lacquer.
Thats what I've thought it was too. Are you mostly using lacquer on your instruments or is that too vague a question and the customer dictate the finish? I guess the better question is what do you perfer to use?
For the past several years I have been moving to the less toxic finishes. I used to use nitro lacquer almost exclusively, and it is a great finish, but the less time I spend breathing fumes of toxic solvents the better I like it.
Each type of finish has it's own strong points, and weak points too. I like spirit varnish for french polishing, it is easy to touch up if needed. I like some of the violin oil varnishes, as they can be quite flexible and extremely thin, and still give a fair bit of protection. The oil varnish I got from International Violin has worked quite well but I am not yet comfortable my control (or lack there of) with it's coloration. Behlen's has a hard varnish that is quite promising, and it can be sprayed if you like. I prefer the appearance of it when brushed, as it levels quite well.
Repairability is of utmost importance to me. Poly is not very repariable as you can't meld the new finish applied to the repair to the old finish. Lacquer can be repaired with the use of cellusolve acetate, but I've written off lacquer as not being conducive to good health. Oil varnish is also not repairable, but spirit is, so spirit over oil is the way to go for me. Both oil and spriit can be sprayed, but Michael is right, they're not the easiest finish to spray. It's taken me years to figure out how to do it efficiently.
I know what ya mean about toxicities...all my missing brain cells didn't come from partying. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wow.gif
OK what were we talking about....??