Official Luthiers Forum!

I bought a can of matte, and a can of satin Osmo polix oil the other day at Woodcraft. I put two coats of the satin on the little Stauffer bridge, and it came out nice. I like the ease of it. We'll see how the matte works on the neck next, and then the satin on the body. I got really nice color from the steel wool and vinegar solution I made up months ago. The wool was in the vinegar about a month. Then I pulled it out, and strained through a coffee filter. In the new jar it was clear and golden. It isn't black, but it will stand out against the spruce belly. The Spanish cedar for the neck will get black.

I went to use it the other day, and didn't see it on the table. I thought it was a jar of shellac. It had turned a nice wine red color. It still works good; but what made it change to red?

_________________
Why be normal?

Hmmmm. Well Iron (Fe) has a reddish color to it so I suppose it could be that. I have never seen it turn red before though.

If you dipped a brush in the jar, you likely contaminated the contents with tannins picked up off the job by the brush. It's the reaction between the vinegar/steel wool solution (ferrous acetate) and the tannins in the wood (or on the brush) which turns things eventually black, if the concentrations of both components are high enough.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Trevor,
I see what you are saying, but I tested the mix back in the winter, A few months later I filtered it into the jar, and it was yellow. Even a month ago it seems like it was yellow. Now it is red.
Aging?

_________________
Why be normal?

If it's changing colour, some sort of reaction is going on. I'd be looking for possible contaminants (e.g. jar seals and closures) first.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I wonder if it might be exposure to sunlight causing the color change? UV can do a number...

Dave

In the basement?

I might have had sandarac in alcohol in the far before, but I cleaned it all out. I never got that beautiful red out of sandarac; although it is supposed to be there.

_________________
Why be normal?