varnish test pic

[Don Harris]

Here's a sample of one coat amber shellac and two coats Behlen's Rock Hard Table Varnish colored with asphalt dissolved in turpentine. I'll do at least one more coat tomorrow to get a deeper brown. I want it to look rich and dark and yet not obscure the purfling.

If it dries well and isn't chippy, then it's time to start on the bass.

[basswraith]

Looks good. Is that spirit based or oil?
I have tried the Behlen violin varnish and it never hardens enough.
I am interested to see how this works.

[Jake deVilliers]

That's a great colour. Can you describe how you got it?

Thanks

[Don Harris]

I hesitate to say how I did it because at this point I'm afraid of someone saying I'm doing it all wrong, but...

I sealed the wood with a really thin coat of Behlen's Rock Hard (oil varnish) padded on and wiped off. Then one coat of Zinzer amber shellac, thinned a bit with denatured alchohol and brushed on. I found a paving crew and talked them out of about a quart of steaming hot asphalt with the gravel in it. I used about a pint of that and added some turpentine to dissolve the asphalt. Poured it off and filtered it, then added it to the Behlen's (about 20%/80%). This pic is with two coats of the tinted Behlen's. So at this point it's mostly oil varnish with a ground coat of spirit.

I had every intention of mixing my own shellac from flakes, but now that I've done all my tests with shellac out of the can I don't really want to change anything for fear of changing my results. On my samples that weren't on stripped wood, with a combination of spirit and oil (sans asphalt), the finish is tough as nails, rubs out great and not chippy at all.

[Darren Molnar]

I'm curious how bass makers got into using rock hard. I've not seen this product in real life, is it really "rock hard" ? How long have makers been using it?

"""I hesitate to say how I did it because at this point I'm afraid of someone saying I'm doing it all wrong, but..."""""""""

Not from this window, Don, but I'll pass on something I've heard. Some have mentioned that a too concentrated mix of asphalt causes craquelier later on, as it doesn't dry as hard as other resins, but it is usually mixed in with harder drying varnishes.So there is some tension there in the varnish film. But I have no real world experience with it, so add a grain or two of salt to this. ( to my statement, not to the varnish ) I don't know at what point is too much, you might want to search m-net, if you havn't already.

You're test looks nice, old world creamy, and not new world garish, I like it.

[Don Harris]

I don't know in general how bass makers started using Rock Hard. I know for me it was from reading about acoustic guitar builders using it as an alternative to spraying. I don't have enough experience with traditional oil varnishes to compare hardness. If you put on a lot of coats and level in between, it can look almost too glassy and smooth so I'm a bit worried about it looking like a cheap sprayed bass. I figure I'll keep the varnish thin and limit my coats to try and maintain some of the wood texture.

A lot of my tests have been with aniline tints in shellac with Rock Hard over it. They seem very durable and thin, but I just don't like the color as much as asphalt. What to do?...

[Darren Molnar]

Haven't varnished a bass yet, but with the other instruments I'm using a ground of some sort, which varies depending on what my zodiac tells me . But right now it's shellac ground, very thin. next comes a rubbed coat of varnish mixed with pumice. Again, very thin. Those two are my ground coat, and thin enough to almost look like it's polished, with no coating on it. After that comes either glazes, or colored varnish, or a combo of the two. I try to keep the varnish/color coats to two coats, max. then sometimes a coat of clear, or nothing, or some times a french polish as a clear coat. My system varies a lot, it's flexible because sometimes I antique, some times I don't.

My color glazes are oil colors, I dont use browns, but make browns by mixing transparent red, yellows, and blues. The glazing technique that works for me right now is to mix my glazing oils with some of the varnish, to make a paste.I'm finding that the closer the color is to the wood, the more intense it can be made, as opposed to trying to get a deeper looking color with, say ,the fouth coat of varnish. I haven't had much luck going that way.

I like wood texture so I'm always trying to keep things a thin as possible.A lot of my varnish coats are rubed on and patted down, as opposed to brushing. And my varnishes come from either violinvarnish.com or magister varnish, out of Holland. I'm not brave enough to cook my own, and I'm not convinced I could make any thing better than what's out there.

But they are crazy expensive, so that's why I'm curious about the rock hard varnish as an alternative for basses.

[Ken McKay]

Don't rule out a tung oil varnish either. I think Matthew used it on his Silky Oak bass. I have finished several basses with it. I mix it with oil colors to glaze and then finish with 1 or two clear coats. It is very thin and dries overnight. Rub out is not necessary with it so it keeps the texture of the grain showing.

[Jake deVilliers]

Don, you could probably just use roof tar in a can for the asphaltic content and not have to strain out the aggregate! Just avoid the fibre reinforced product.

It sure makes a perfect colour. Thanks for sharing.

[Matthew Tucker]

Although a local luthier swears by it, I found the Tung Oil finishes that I could get here were far too easily absorbed by the wood. Really penetrating. So I used a heavier danish oil formulation over a shellac sand/sealer base. For my next bass I think I'm going to try a propolis soap ground with a special spirit varnish recipe over it.

[1st Bass]

I used shellac to seal, tung-oil varnish with artist colors to glaze, and tung-oil to finish. (My photos are on the "progress report" thread.) The Tung oil varnish won't penetrate past shellac....

[Don Harris]

"you could probably just use roof tar in a can"

You know, I tried a few different things, and a lot of the products have solvents that wreck the previous coat. The road stuff has been the best so far. I'm getting cold feet though. Building the color with an oil varnish is going to make too thick a finish I'm afraid. Using a spirit varnish to color with padded on oil keeps it really thin.

Darren, I'm looking forward to seeing pics or your bass varnished. I toyed a little bit with mixing artist oils and glazing and never really got a handle on it. Couldn't get away from a really blotchy look, and getting the color right wasn't so easy either. I haven't given up on it completely though. Just not on this bass.

Got my first coat of amber on today. Geez... a lot harder than brushing on flat sample boards!

[Darren Molnar]

There seems to be a lot of variation with tung oil. Tung oil could be pure oil, oil with solvents added to make it thinner, polimerized oil to make it thicker, oil with driers. then there are some that are labeled "tung oil finish", which i think is a different oil with added resin to mimic the properties of true tung oil. Is tung oil the same as China oil, also?

[Don Harris]

!stBass, did you pad on the tung oil varnish or brush? Your bass looks nice. I like the way the color went on.

[Darren Molnar]

Oh yeah, I forgot to ask 1stbass, ( which was the whole point of my little rant ) what brand oil you used. 'cause that seems like the right stuff to use, regardless of what's actually in it. It looks really nice.

[Darren Molnar]

I wouldn't worry about the cold feet, Don. Looks like you got all you're ducks in a row.

It is tuff to control blotch with glazes. It usually means there is too much product being applied at one time. or that it is drying before there is time to even it out. I'm curious how mine is going to turn out, as well. This bass I'm making seems to be wearing the pants in my family right now. It might be that it spits my varnish out, and tells me to make it another sandwich.

[1st Bass]

I used a product called "Formby's High-gloss Tung-oil varnish"-- I have no idea what is in it. I believe you are supposed to pad it on, but I brush it.

I use artists oil colors to tint it, preferably as transparent as possible, and turpentine to thin it. It dries very rapidly-- in warm weather, I can sometimes re-coat in an hour or so-- maybe two hours, say. You can rub it back if you don't like the gloss...I do so, after it is completely dry and hard. That usually takes a few days after the final coat.

It is quite thin, and somewhat prone to run, so you want to keep checking, and re-brushing until it firms up. My varnish stand helped me to keep the area being worked fairly level, so as to minimize the tendency to run.

When I am using it for a glaze I add a little linseed oil, to stretch the working time, otherwise it goes off rather suddenly, and may leave you with the color not looking the way you want.

This is essentially what I have used on all my instruments, but I intend to try something else soon-- I'll let you know how it turns out. I saw a cello done this way, and it looked very good. (a spirit varnish technique-- can't say more yet, 'cause I simply don't know yet)

Chet

[Ken McKay]

You can read about wiping varnish and "tung oil finish" and what it means from reading this link by Bob Flexner. http://www.popularwoodworking.com/features/finish2.html

When I refinished my first bass in the late 1980's there was no one to help me. I had to go on what I read from the SCAVM (Southern California Association of Violinmakers) and old books. I though I would experiment with some hardware products. I looked and looked at the labels and didn't any of the varnished seemed quite right. I tried several different brands. I happened to have some Formby's Tung Oil Finish and tried it not expecting much, but it looked better than any varnish that I had tried. It was easy to apply since it was thin and it dried hard in a day. Nobody told me I couldn't use it so I just used it. I used it straight out of the bottle for the ground. I mixed it with artists oil colors to glaze the color on and finished up with 1 or two coats of clear. I probably refinished 5 or 6 old plywood basses and a German or two. It did not alter the sound before versus after so I am confident it is a good finish for bass soundwise. I wish I could have a look at those now but they are long gone. I think they would still look good to me. I have noticed that a lot of refinishing of basses (or violins) result in a finish that although transparent, looks ..."refinished" or artificial and often pale.

I am not talking about a new bass with clean workmanship which deserves a clean transparent varnish.

I bought the Hershey Violin DVD on Spirit Varnishing last month. It goes into a single method of making a high quality spirit varnish as well as a ground, nut stain for bringing out the top grain and applying the varnish. It results in a real clean looking varnish and is the standard method for the Bebenruth Germany makers and the Roth, Gill type instruments. It is a nice finish but doesn't look Cremonish to me, more German bench made not german factory.

[Martin Sheridan]

There are so many things that you will read and hear about varnishes that aren't true that I present this only for informational purposes. It's information I've had from luthier friends I admire, but I can't verity it.

Rock Hard oil varnish was originally called, I believe, a tung oil varnish but it didn't sell well so they changed the name. It actually has tung oil and a resin mixture along with some other stuff. Don can read the can and tell us.

Most products advertising themselves as a tung oil finish have about as much tung oil in them as you'd get if you passed the can over the fumes.

Just the thought of asphalt scares me.

[Don Harris]

On the Rockhard can: "Rockhard Table Top Varnish is a quality phenolic resin "short" oil varnish, amber in color; which develops a hard, solvent resistant, gloss finish."