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I have a finishing question - - - I'd bought a b/s set of 'boire' and it had a great number of dark lines of sap weeping along the grain. Sanded to thickness, looked good. A week later, not so good. Still weeping. Washed off with naptha, a week later, still weeping. Gotta stop sometime, I hope.

My question is, is a seal coat of shellac applied right after a wash-down going to allow me to do a nitro finish? Will I be gifted with weeping sides that will forever contaminate the finish? My only experience with shellac sealer on weeping wood is in sealing pine bookcases for a painted finish. Seemed to work, but that's much less critical than instrument wood.

Any advice, I'd love to have. Thanks!

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Peter Havriluk

Generally, I don't use shellac with nitro. Only vinyl sealer. But then I doubt either will lock in the sap. You might do an experiment with CA or epoxy as a pore filler on bare wood to see if that will do it. But then a problem may not show up for several months.

I bake my backs the same way I do the tops to set the sap, among other reasons, but it is too late for that. Some of the expert finishers here may have a solution. Good luck.

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Joe Beaver
Maker of Sawdust

A heavy coat of shellac will usually seal in sap, but nitro doesn't particularly like to stick to a heavy coat of shellac. You might try a shellac finish and french polish the last few coats to bring up the gloss.

you may need to let that set age some more.
Let the oils & such dry up- It will not all be gone but will bleed less
when it's had time to dry.

Mike

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Mike Collins

Mike, thanks for speaking up. I hadn't considered that possibility at all. I was working on the idea that any wood sold by a vendor was ready to use when received.

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Peter Havriluk

What did the vendor have to say?

Might not be the best idea, but if I were in a hurry I'd line my mold with paper towel, insert the sides and put it out in the sun half an hour or so at a time until it sap stopped leaching ----- try at your own risk.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Ken, I think the vendor was originally skeptical of my complaints. Once I sent him pictures, he sent replacement sides which were a whole lot less weepy. I suspect, without any discussion with the vendor on the topic, that when he sent me the sides they had just been sanded, and the weeping was masked by the processing of the wood. Looks just fine immediately after sanding. When I opened the package after a few months, I noticed the weepies and started a conversation, and that got me replacement sides that weep less, but weep some.

I wasn't sure that my concerns were reasonable, and I did not press the matter with the vendor. But we consumers, should we expect that wood we purchase won't be doing this weeping, and as such, it warrants replacement? Expanding the question, what characteristics of tonewoods we purchase, typically by mailorder or online auction, are appropriate to raise a complaint call to the vendor?

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Peter Havriluk

I only buy sets from suppliers that I've know & trust.
No E-bay ,or other sources that have no known track record.

If the price& deal sounds to good -it's probably is !

There are tons of "Great Deals" on the net!~

And if you do get wood from a private dealer-ask his return policy!

Mike

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Mike Collins

While I won't name the vendor, it was one with a well-respected presence in the tonewood business. Not a nameless someone peddling on an auction site. I think the vendor received wood that should not have entered the market as tonewood, and it went unnoticed until I let the wood sit in a package for six months. I've done business with that vendor since receiving that weepy wood, and I happily would again. As for returning, I think I let too much time pass before speaking up. I had an obligation to raise timely questions and I didn't.

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Peter Havriluk