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I used StewMac's clear waterbase grain filler on this batch of 3 guitars. 3 applications/sanding of grain filler and it did not do the job. (Now on coat 38 of Target EM6000. Please don't hurt yourself laughing.) I really like the concept of a clear grain filler and want this to work.
Questions:
1. Is there anything wrong with putting a coat of sanding sealer down first before applying the grain filler>
2. What about adding SystemThree Silica Thickener to the grain filler to help fill the pores.

VOCly yours,
Bill

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Formerly know as Mandodiddle.

Are you talking about regular sanding sealer or some new water based type?

Sanding sealer is meant to provide a quick surface buildup for use under lacquer top coats for use in production furniture (etc). It's not actually meant to fill pores. Typically a couple coats are applied over bare or stained wood, sanded flat, and followed by a couple thin coats of lacquer off the gun. This is meant to save time and materials, and is a lower standard of finish than is expected in guitarmaking.

As to you question #1, I'd worry about adhesion issues, since it is basically soap dissolved in lacquer. You could always try it on scrap.

AFA #2, I guess you will have to try it.

Let us know how it works. I think a lot of people would like to have an alternative to epoxy that is clear.

I typically put sealer down before and after the pore filler.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I did a lot of experimenting with the clear water borne grain fillers --- not for me. But one thing I found that greatly improved the results was to more or less "water proof" the surfaces with a solvent based sealer which actually take a couple of coats. That said, no matter what type of pore filler I use the first step is to seal the wood to trap the oils and resin.

I am not a fan of sanding sealer since it is by design a very soft coating so it can be removed/sanded easily -- I am not sure this is a good idea under some top coat products? I use a vinyl sealer.

Brian H. does finishing for a living so I'd say he offers some really sound advice and its great that he shares his expertise.

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Ken Cierp

http://www.kennethmichaelguitars.com/

I spray vinyl sealer x 2 before pore filling, then sand, then one more sealer. This is over pigmented filler but it gives great results.

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It will probably be alright.