Violin Forum/Message Board

Muswell · Posted: Thu Dec 22, 2011 10:52 am Post subject: Yellow marks in maple

I haven't been able to find any information on this so I thought I'd try here.

The back I am working on has a slight yellow tint for about 15mm on each side of the centre-line. I found the same some years ago working with sycamore. Is this a fungal "infection"? (There is also a 25mm lens shaped spalting mark on the centre-line.

Is this likely to fade in time, and is it likely to be masked by the varnish? I'm not losing sleep over it, just curious to know more.

tomigv · Posted: Thu Dec 22, 2011 4:55 pm Post subject:

Have seen many similiar stains in sycamore more brownish/blackIMHO they just add character.
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Muswell · Posted: Thu Dec 22, 2011 8:22 pm Post subject:

The black/brown spalting mark adds character, I agree. I'm more concerned about the yellow tint which is a stripe running the full length of the back. Have you seen that before?

Dave Chandler · Posted: Fri Dec 23, 2011 2:41 am Post subject: yellow in center wood

I've seen some reddish coloring even some blueish if the wedge goes out into the phloem area near the bark. This carries water and nutrients up into the tree. I once spilled some concentrated "roundup" on some logs I had split, and it soaked way into the wood in a bright yellow. What a mess. I'm not sure if this phloem area is as solid as the clearer areas. The only back seam I've had fail, failed in an area that had heavy deposit of spalting. Some discolor will pretty much cover with varnish, if it still shows, you might want to go a bit darker, or just let it show as part of the beauty of a non-factory violin. But if the spalting is right on the seam, I'd put a cleat or two for back-up on the inside of the seam.
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Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

Muswell · Posted: Fri Dec 23, 2011 5:26 am Post subject:

Thanks. I'll follow your advice and put a cleat on the patch of spalting. I'm guessing the discolouration will be lost in the colours of varnishing but that will be a new area for me...my previous instruments were guitars finished with oil or french polish. I'll give my tonewood supplier a call and ask him if he can explain what causes the yellow.

Dave Chandler · Posted: Fri Dec 23, 2011 1:16 pm Post subject: Yellow color

You might consider first coating with thin layers of yellow varnish avoiding the stained areas, to make the tone more even. I use yellow as my first varnish color anyway to get a golden tone below the brown.
_________________
Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

Muswell · Posted: Sat Dec 24, 2011 5:54 am Post subject:

Yes I'll do that. I asked the tonewood supplier if he knew the cause of such marks and was told that it was a natural product. I resisted my urge to thank him profusely for such a profound insight and persevered in an attempt to find out how common it is and what causes it. No luck.

okawbow · Posted: Sat Dec 24, 2011 1:38 pm Post subject:

I don't mind a little "mineral" stain on my maple. I use a propolis ground, then a ruby shellac coat, which helps even out the color. After varnishing, I can't tell where the stains were. I can usually get wood with staining at a discount. There doesn't seem to be any difference in strength or tone either.