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i'm thinking about finishing my most recent build with varnish and oil.
i've used nitro, and water based lacquer in the past.
so my quetions are, what brands are instrument grade, how many coats, and what's the procedure, down to the polishing.
i saw some pics on laurents web site, and really liked the rich look of the varnish.
oh, how does this stuff hold up?
alan

You mean you want to use an oil varnish?
The ones I've used are Behlen's Rockhard, Behlen's water white restoration varnish, Ace interior oil varnish and Epifanes clear varnish. I have a couple of quarts of Pratt&Lambert #38 I haven't tried yet, but others use it successfully.
Do you have a compressor/spray gun rig?

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

hey laurent,
i was hoping you'd pipe in here.
i really like your guitars,
i'm going more and more to just wood inlays and such meself.
i do have a compressor and a little old binks touch up gun that still works well,
so i'd be using that.
i'm guessing i would apply coats as usual, sanding between when necessary,
let it cure for about three weeks, then polish it out when hard enough.
any other hints?
i don't have a buffer, so it's all by hand.
maybe this is why i've been taking so long to get a finish on this beast.
haven't been totally satisfied with the waterbased,
love the nitro finish, but not using that stuff anymore, too nastay to work with.
thanks!
ace varnish you say?
alan

Yes, Ace interior varnish.
If you search the archives you'll find multiple threads where I and others (Al Carruth I believe and Woody B. perhaps?) described some the process, read that and shoot back with any more questions. You need to scuff each coat of varnish before applying the next, oil varnish is unlike lacquer in more ways than you think.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I've been getting the hang of Rockhard varnish for several years now. One thing I've found is that 'less is more'. That is, I've simplified the procedure, and now get better results.

I brush it on, but thinned out to about spray consistency. The key is to keep it level, so that you don't have to do too much sanding at the end. I like to really level it out part way through, and then do the last 4-5 coats very carefully. Do the last two coats the same day, if at all possible. Let it sit for at least a week before starting to buff out.

I was having some trouble with scratches that I could not get out, and thought that maybe the problems were with my old Micro-Mesh, and maybe the pumice. Using only wet-dry paper helped, and skipping the pumice stage helped more. At this point I go with 1500 and 2500 paper (some high-tech Japanese stuff I got at the auto parts store), and then right into rottenstone and water. This gives a very nice shine and does not leave a residue as plastic polish does. The polish does give a higher shine, though, and I'll do that at the last minute before a show.

I'll note that I still don't have a buffer, but this process seems to do about as good a job. It's a fair amount of effort, though!

Alan,
I'm on the home stretch of finishing a guitar with Behlens Rockhard and I like it a lot. I reached out to both Laurent and Bruce Sexauer for advice and am very glad I did as it went very nicely. (A big thank you to Bruce and Laurent)
The only thing that drove me nuts was DUST! No matter how clean I tried to keep the room it seemed dust found a way to get stuck on the surface. Good news is that you have to scuff sand between coats and it takes out most particles.
I just found out my local marine store stocks Epifanes so I am planning on using it on a Cedar/Mah OOO I have ready to go.
These guitars are for my kids so I have a few to finish in order to get the learing curve down. Just remember to keep your acetone and turpentine handy as this stuff gels up in the can very quickly.
Ray

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Guitar Building = Continuous Improvement Process

I've used Epifanes on several guitars.(20+) I spray it so I can't comment on brushing. A super clean spraying room is a must. I add 25 to 50% thinner, as well as up to 25% Epifanes accelerator. I don't use any accelerator in the last coat. I've used Epifanes thinner, Naphtha and (at Laurents suggestion) Turpentine. I love the smell or turpentine, (wear a respirator while spraying, even if it smells good) and I believe it flows out better than the others. I also like the idea of using a product that isn't derived from petroleum. (doesn't turpentine come from trees???) I usually end up with 6 coats on the top, with some woods getting a couple more for the back and sides. I wait 48 to 72 hours between coats. I scuff sand with 600 grit on a RO sander at low speed between coats. Any finer and you'll probably have adhesion problems. If sanding by hand I'd recommend no finer than 400 grit. Be careful sanding on the first few coats. It doesn't have to be perfectly level. If you sand through you'll probably get wittness lines. If you do a good job with prep and spraying it doesn't take much sanding. I use a pedastal buffer with Menzerna medium then fine, after lightly sanding with 1200 grit and a RO sander on low to remove dust specs. Final thickness, with my techniques is around .004". I always measure the thickness behind the soundhole, where the center seam meets the rosette to see how much thickness I'm building, and sanding/buffing off. I've buffed as quick as 8 days after the final coat, but usually wait 2 to 3 weeks.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

thanks for the advice.
i did forget about the dust settling on a finish that doesn't go off fast.
guess i'll be careful with that.
i'll post pics in a month, i hope.

Some people like to do a thin frensh polish over the varnish, especially mandolin builders who make replicas of early 20's Gibsons, as this was how they did it back then. Another fairly common "topping" over varnish is tru-oil, which seems to even things out somewhat, and give the surface a smoother sheen. I did this on a recent mandolin, over Epifanes, and I liked the effect. It can also help mask witness lines, if you have those.

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Rian Gitar og Mandolin

I think a lot of the particles you get in brushed varnish are 'sand': the little particles of varnish that dreid in the brush. As you say, scuff sanding between coats gets rid of them.

Alan is right. If using a brush more than 1/2 the length of the hair, some varnish will migrate up under the ferrule, eventually dry, and sprinkle the work a bit. To avoid that, never use more than 1/2 the length of the hair (like don't dip the brush in the varnish up to the metal ferrule…), and suspend the brush in a solution of turpentine between sessions up to just under the ferrule. The more a good brush is used, the better it gets IME.
When using a spray gun, clean with any varnish solvent (turpentine, naphtha, mineral spirits) but never with acetone or lacquer thinner: it makes the varnish residue curd inside the gun, and eventually will spit bits out on the work. Best practice is to strain the varnish, of course, especially for the last couple of coats.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/