Finish on a burl top

[gbarcus]

I've got some redwood burl that I'd like to use, but I have a bass that I did a couple years ago and the nitro is showing little lines around the darker areas of the burl where there is a higher concentration of sap.
I thought about spreading a thin layer of System 3 epoxy across the top before finishing, but it's not something I've tried.

[tjclem]

Redwood burl can be a bitch like that good luck...t

[ON the ONE]

If the burl is from that same stock as your previous bass, I'd try "setting" the pitch. This can be done by cooking at a low temp (+/-125 degrees) for a few hours. This will crystallize pitch in wood that has already been kiln dried and seasoned. It works especially well with softwoods to stop the sap from creeping to the surface. Cook it low and slow. I think Bob Taylor did an article on this for the GAL back in the 80's. he used his kitchen range for this.
Also, experiment with different sealers. I'm no nitro expert but I am told that vinyl sealer will stop any oils etc. from reaching the surface and causing fish eyes or discoloration.

[Lonnybass]

I've got a redwood burl finish build in progress using varnish/oil/dye...let me know if I can help!

Lonnybass

[gbarcus]

Thanks for the replies. I haven't heard of the setting the pitch, but it makes sense.
I don't have a project in mind for them anytime soon. Still have the slab uncut. should be able to get about 6 tops out of it though. It's been sitting here taunting me for the last year and a half.

[Lonnybass]

The challenge I had with my sinker redwood burl was a fairly sizable amount of brittleness and some splitting along the top.

As such, I was a bit nervous about the strength of the laminate in the area of the control cavity because it doesn't have underlying core wood for strength, so I took the precautionary measure of glueing a thin layer of 3/16" polycarbonate to the inside floor of the cavity to give the wood a solid and strong backing.

Lonnybass

[gbarcus]

I soaked mine with some ca glue in hopes that it would stabilize it. Seemed to work ok, but I like your idea better.

[Lonnybass]

Originally Posted by gbarcus

I soaked mine with some ca glue in hopes that it would stabilize it. Seemed to work ok, but I like your idea better.

You can get small sheets of the polycarbonate pretty cheap, I think it was like $5 or $6 at Home Depot. No joke, I have had visions of that entire control area just crumbling on me when I drill out for the pots! At least this way I know it has a solid backing to hold it together.

I was surprised though at how much the wood checked on me in a few spots during the first couple coats - I've never had a topwood do that before. In the photo below, it's the burl that fans out from the area of the two pickups.