oil paint refinishing failure please help

Vince_P9 · #1 12-10-2009, 09:46 AM

I diluted artist oil paint in TruOil to refinish my bass and so far it looks absolutely horrendous. I plan on sanding it off as soon as it dries. After I sand off the layer of oil paint, it will be back to a natural finish (two coats of pure TruOil). Can someone please advise me what to do next before I throw my bass off of a rooftop? Thanks.

Bill Bentgen · #2 12-10-2009, 10:26 AM

1. Buy a commercial string instrument oil varnish.

2. Read a good resource on how to do it.

3. Practice on a spruce or pine board until you get it the way you want it.

wayne holmes · #3 12-10-2009, 06:49 PM

no sanding-use paint/varnish remover- call Ken at International Violin for varnish and instruction-very helpful.800--542-3538

draftsmann · #4 12-11-2009, 12:57 AM

Disclaimer first: IANAL

I used Tru Oil to finish my project bass, and used diluted artist's oil paint for intermediate colour glaze coats. I found that the colour glaze needs to be made in very small quantities, stirred thoroughly and used immediately. It starts to separate after a few minutes. I also found that it is best not to use too much colour - depth of colour is best built up with multiple glaze coats. Remember that artists' oils are very slow-drying. The Tru Oil acts as an accelerator, but still I found it best to leave it for two weeks or so before cutting back the glaze coats with 400 grit paper. Cutting back will also reveal any "soft" spots where the oil paint has not been thoroughly mixed with the Tru Oil. These were relatively easily repaired later. I used my fingers to apply the clear and glaze coats and to spread them thinly, other than on the scroll, heel and nooks and crannies, where I used a tiny brush. After cutting back the colour coats and doing a number of spot repairs, I applied three or four very thin clear coats, again left the bass for a couple of weeks, and then used ever-finer grades of Micromesh for final cutting and polishing. The end result was far better than I had ever hoped. Don't give up!

Adrian

arnoldschnitzer · #5 12-11-2009, 06:15 AM

If you mix your oil colors with Liquin first, they will emulsify and blend. Then you can stir a small amount into your Tru-Oil and it will mix well and go on evenly (add through a strainer). It also helps to warm the mixture up--to body temperature or so, using a jar in a water bath. Do not warm up varnish directly over an open flame or hot plate! Tru-Oil is an excellent finish, but it is very thin and can only accept a small amount of pigment at a time. It will dry hard overnight, and you can re-coat the next day.

Vince_P9 · #6 12-12-2009, 08:58 AM

Thanks everyone. I think I'm going to put the oil paint technique aside for now and try JOHA spirit varnish. I just ordered a single bottle to experiment on some scrap maple with.

moles · #7 12-12-2009, 01:41 PM

This is great info. I'm planning on refinishing mine in the next couple of weeks while I have some time off for the holidays.
Vince, do keep the updates coming...

draftsmann · #8 12-12-2009, 01:53 PM

Again, qualifying this with the "IANAL" disclaimer, but I'd be interested to know the views of the pros on applying spirit varnish over Tru Oil. I believe that Tru Oil actually penetrates the wood to some extent, rather than merely acting as a coating. Remember the stuff is sold primarily for finishing gunstocks, which it does admirably well (another interest of mine!), and is the more modern counterpart of the traditional boiled linseed oil stock finish. So I doubt it is possible to remove the Tru Oil altogether.

Vince, I have to confess that when I finished my bass I did get a few nasty runs in the colour glaze coats (by Murphy's law, in the top - why couldn't they have been somewhere less conspicuous?)

I found the Tru Oil remarkably forgiving - the runs were easily removed with 400 grit paper. Before you give up on the Tru Oil, why not try cutting it back somewhat with 400 grit and recoating?

Bill Bentgen · #9 12-12-2009, 02:06 PM

The only instrument I've ever finished is here:

http://www.billbentgen.com/bass/imag...ght_f_hole.jpg

But I've had a lot of experience finishing wood panels in my library. The trick there was to use a water soluable stain and cover it with an oil varnish. The water soluable stain is not dissolved by the oil varnish and that 3 dimensionable that you see in really fine violins was achieved.

Vince_P9 · #10 12-13-2009, 09:05 PM

I just finished stripping the bass (again). The TruOil came off quite easily with the same KleanStrip paint remover that I used to take off the factory finish. While waiting for my spirit varnish to come in, I'm revisiting the TruOil/artist paint technique on some scrap maple with some very pleasing results. My mistake on the first attempt was simply adding too much paint. The tricky part with this project is, I need a varnish that I can build up in select areas to a near opaque finish. There is some sizeable cosmetic damage dead center on the top of the bass (bridge area) which has been filled, but looks like, well, filler

. I figure the location of the damage is fairly convenient, seeing as if I have to make any area on the bass opaque, it would probably be most asthetically pleasing to have a fade from opaque to transparent from the center out.