Official Luthiers Forum!

ok so with all the reading ive done on mixing shellac , tru oil , and z poxy i should be a expert but, i m still confused. hears what i plan on doing. b&s eir , bindings- koa,neck mahogany- z poxy then tru oil. for the top im still confused. do i seal with shellac then can i use tru oil or just shellac? for the shellac is a 1# cut ok? is 2oz shellac- 8 oz alchohol a 1# cut and is that enough to do the top? only a couple more questions. should i do the top or b&s first? or z poxy b&s shellac top then tru oil it all? as you can tell im confused. thanks for your advice in advance. id be lost without this website.

jeremy

If you are going to use true oil, just use true oil and forget about anything else as it will fill the pores as you layer the coats. Do the top first to avoid any bleeding color issues.

If you insist on sealing the guitar with shellac, then do the top first and be careful not to carry over any color from the koa bindings over onto the top. Once it is sealed with shellac, you wont have any more issues with bleeding colors.  The blend volume you state is enough to seal several guitars. It doesnt take much at all just to seal a guitar.

One word of caution: If you decide to sand the guitar after sealing with shellac, dont sand through the shellac or if you do, sand ALL of it off of the top. If you leave a sanded through spot visible, it will cause blotches in the final finish. (voice of experience)

 

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Reguards,

Ken H

what else could i seal the top with? i really dont want to change the color of the spruce . i test tru oil on a scrap piece of spruce and the color was to my liking. i have some leftover aerosol sanding sealer from stewmac from my last guitar, would that work?

that is what I am saying... you dont need to seal it at all..just go for it with the true oil.

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Reguards,

Ken H

Jeremy, I think you must seal the top with shellac to keep the tru-oil from penetrating. It goes on great over shellac. On the back and sides and neck, it isn't necessary to seal first, but it doesn't hurt either. I put a seal coat of shellac on everything except the neck then start the tru-oil.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

I would think the true oil will darken the top more than the shellac. so I don't see the issue with the shellac sealer.

Just a word of warning again. Seal the top and light binding and or light colored purflings before Zpoxying. you can scrape the shellac off after the back and sides are filled to fill the bindings...Do not seal the back and sides with shellac prior to zpoxy filling the back. over a larger area there is issues with Zpoxy adhering to shellac and can flake off. You can seal the back and sides with shellac after pore filling if you wish.

thanks for your help guys. i went ahead and sealed the top with shellac and now im pore filling back and sides.

Personally, I would not apply Tru Oil to a soundboard without any kind
of seal coat.  Because TO is a penetrating finish, just
intuitively I would think it would dampen the top's vibration.

[QUOTE=erikbojerik] Personally, I would not apply Tru Oil to a soundboard without any kind
of seal coat.  Because TO is a penetrating finish, just
intuitively I would think it would dampen the top's vibration.
[/QUOTE]

If I use Tru-oil on a top now I do put it over shellac seal coats ... BUT . . . this baritone (far right) had Tru-oil applied direct over three and a half years ago, and if you think the tops vibration has been adversely dampened then check out this sound clip. All finishes penetrate to some degree and if applied in thin coats, Tru-oil doesn't penetrate any deeper than shellac imho (based on some repairs and re-finishes I have done). I now use Tru-oil over Z-Poxy on my necks and like the result very much.

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010