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I wanted to try some Nitro on my current build,and I know a lot of you folks have used shellac as a sealer under it.Do you brush it on,spray it ,or maybe rag it on? Also does it need to be sanded lightly after application,before shooting the Nitro,due to grain raising?
Thanks,
James W B

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James W Bolan
Nashville Tennessee

You can apply it by any of those means however ragging it on might give you a smoother surface and I would scuff very lightly or more if it's not smooth. Schellac shouldn't raise the grain though.

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Tickle your guitar daily, and it'll tickle you back.

spray works the best for me. Brushing always leaves marks unless you thin it considerablely.

Joe

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Joe

Spraying works best for me, several light coats.

One of the problems with shellac is that the alcohol will bleed the color out of some wood, especially rosewoods. If you use rosewood in your rosette or purflings, brushing or ragging shellac on can bleed the color from the wood and then smear it all over the place. And that doesn't look too good on spruce or maple purflings lines. Spraying light coats of 2 # cut avoids this problem.

Mark

Does epoxy have this same effect? I'm doing my first rosewood guitar and was a bit worried (won't be ready for finishing until winter though).

Last instrument I used shellac, then the stewmac water based pore filler followed by USL but there were no runny woods.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

That is a bit out of order in terms of my schedule. in my book sealer goes on just before the finish. never before the pore fill. I prep sand, pore fill, seal and finish in that order

Shellac may inhibit some prefillers adhesion. I know this can be the case with epoxy pore filling

Some builders spray nitro directly over epoxy but I seal the pore filled body with shellac then finish

FYI I spray 1.5# cut of shellac as my sealer in most cases

So far as i could tell, there were no issues with the water based filler sticking to the shellac...on the other hand, I did have to do two or three coats to get them all filled properly...hmmm.

My worry about doing it WB filler first then shellac would be that the pore filler would cause the RW to run. I would think that spraying shellac first would seal the color.

BTW, on my last instrument I was pore filling walnut and the WB filler didn't have nearly the grain pop that shellac does and that's why I did the shellac first.

I have a little scrap of RW that came with the kit that I can test on though.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Let me then suggest you try Zpoxy finishing resin or Medium thick CA as a pore filler if looking for great grain pop. In most cases Zpoxy will fill in one maybe two applications but if you try epoxy do not shellac first. Wait till fill is complete and sanded back then seal with shellac.

As I always tell everyone Shellac will adhere to darn near anything. Epoxy is sometimes problematic adhering to shellac.

Zpoxy might be an option. I assume that it doesn't make the color run in rosewood?

I really really hate cleaning up epoxy - is Zpoxy like that or is it softer or something to make it sand easier?

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Zpoxy finishing resin is a top coat epoxy If properly mixed (it is very forgiving on ratio) and allowed to cure 24 hours it sands nicely. I dont reccomend leaving a heavy film on the guitar. I sand back to wood everywhere leaving the Zpoxy only in the pores. The make a 60% alcohol/ 40% Zpoxy batch and pad on just enough to color the wood. Then seal and finish.

Sealing before filling the pores is the only way to avoid staining the wood if you are using a colored fill. I've also found that while you can fill with epoxy directly on the wood, the squeegeeing seems to feel smoother with a wash coat of shellac first. I never had or heard of an issue with adhesion of epoxy to a pore because there was shellac under it. But that's with sanding back to wood after filling, so we are only talking about the pores.

None of the finishes we use requires a coat of something else under it in order to adhere well to wood, or to seal the wood from the outside elements. The finish industry seems to like to promote misunderstanding of this, so that it can sell two products--sealer and finish--instead of one. But it is useful to use a coat of something to set up the loose fibers left by sanding raw wood so they can be cut by another light sanding. It's also useful to raise grain and resand. Shellac does both--raises grain a little, locks fibers, and it sands pretty well (better than lacquer, anyway).

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I am not real familiar with epoxy fillers. What does it do to an instruments accoustical value? I am wondering if it dampens the tone/vibrations of the top and back? Yes it is only the pores, but in a way, the pores also helped create the original tone (tap tone) that you tuned the top to. With it now filled in, does it affect this?

I mostly use a grain filler and then a sand/sealer or shellac in that order.

Thanks.
Joe

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Joe

left only in the pores no more than other fillers