Double Bass Finish question

[Jfoureman]

I have a fully carved czech bass circa 1920. Somewhere along the line someone painted it brown. While removing the paint, I actually stripped it down to the wood (only on the back so far). So now I need to refinish the instrument.
My question is should I go with an oil finish like tru-oil or waterlox, or should I stain and then use a thin coat of polyurethane gel (like you would furniture). I have heard that both options actually kill the sound a little, so I'm not sure what to believe. Any advice would be appreciated.

 

[lcdck]

Tru-oil or Waterlox will not kill the sound as they will go on very thinly even with multiple coats. Any Polyurethane will be thicker and probably less flexible which would be more likely to mute the resonance of the instrument.

There's a little info on this in the forums if you search.

Here are some:

http://www.talkbass.com/forum/f3/finish-question-our-esteemed-luthiers-52755/

http://www.talkbass.com/forum/f3/idiot-proof-finish-no-tinting-just-protection-758826/index2.html

I refinished a bass that was spray painted silver this past winter and had excellent results with tru-oil and oil paints for tinting. Having been through this recently I would advise you to go very slowly, realize that it will take longer than you think it will, and do some test samples on a few decent sized boards, from start to finish. I would advise not staining the wood in any way and instead to do a few ground coats (clear coats or very lightly tinted) so that you or anyone else can get back to raw wood if necessary.

MollyKay was a big help to me in answering a few questions. Her husband is very experienced and does excellent work.

Also realize that in stripping, you're liable to remove some glue from the seams so you may have to take it to a luthier for a glue-up when you're finished. I had to.

My bass before:


After:

 

[Michael Eisenman]

Wow, what a transformation! Nice.

 

[Jfoureman]

Wow! The bass looks great. What oil paint did you use? And thanks.

 

[lcdck]

Thanks!

I believe I used a combination of Raw Umber (or possibly burnt Umber), Burnt Sienna, and a Cadmium Orange or Yellow. I can double check by looking at what paint I have. I read a post by Arnold Schintzer and used his recommendations for the colors.

I did at least half a dozen samples of various layers in various orders but what I ended with (again if I remember correctly) was two coats of clear, a coat of yellow/orange, a darker coat of Umber, a few more coats of Burnt Sienna, and then two or three coats of clear on top. I wet sanded between coats to keep it smooth.

The finish in the photo looks a lot shiner than it is now. It's more matte than it looks in the photo.

 

[Chris Fitzgerald]

Wow, what a transformation! Nice.

+1

 

[powerbass]

Wow, what a transformation! Nice.

Really nice job!

 

[Heifetzbass]

I have refinished an old Roth bass that was a nice bright orange color to a nice golden amber varnish. Unfortunately I don't have pics because the owner has the bass and I didn't think to take them before I delivered the bass! Doh!

On Arnold's recommendation I used Waterlox. I had really good success with it. I sealed with shellac and then put on a ground coat of Gamblin Transparent Earth Yellow. I then proceeded to go darker with the pigments and finally used Asphaltum dissolved in Turpentine for the final colorant. It added an aged hue to everything. I then sealed with a couple of thin coats of Waterlox and rubbed out the finish. It came out really nice.

I want to recommend that you use Liquin to disolve the colors before you put them into the varnish. They really flow better and mix with the colorant. Or you can use the glazing method, which is basically finger painting with the colors and then putting on a coat of clear until you achieve the finish you want.

Surface prep is everything!!

Best,
Brian