Bubbles!

[roger wiegand]

I'm started on the road of trying both spray applications and water based finishes. The known unknowns and the unknown unknowns far outweigh anything that might be known.

I'm working on a ca 1895 Aeolian grand player reed organ in a Brazilian rosewood veneer case. It was originally finished in shellac; I've stripped it, done quite a bit of veneer repair, made some replacement parts that were missing, had all the nickel metalwork replated and am beginning the refinishing process.

The rosewood, both the old material and new(er) veneer I acquired for repairs have substantial deep pore structure. Ive been experimenting with pore fillers and with different finishing methods. I've given everything a wash coat of a dark de-waxed shellac to bring the old and new parts to similar color values and because my stripping certainly left some traces of shellac behind.

First thing I tried was a quick and dirty french polish. That went well, the wood looks beautiful, but it is a lot of work for such a big piece, I don't have a clue of how to get a similar looking finish on the fairly extensive, ornate carvings, and both old and new veneer, especially the new shows the deep pores. Trying to fill with pumice and sanding dust in the traditional way was clearly going to take forever, give me repetitive stress injury, and left light color in the pores that is extremely unattractive.

So I tried, with help from folks here to apply GF EM2000 as a topcoat, with or without Goodfilla Clear Grain filler to fill the pores. The Goodfilla dries white, I scraped it with a plastic scraper and then sanded it down.

The issues-- 1) on the old wood, without the grain filler,I was hoping the finish might build enough to fill the pores. It looks OK on the flats, but each of the pores generated a bubble or string of bubbles that are quite pronounced in the final surface. 2) On the new veneer, with the filler, the grain wasn't particularly well filled, there were the same bubbles, and the filler stayed white in some of the pores (this was after drying for 24 hours).

Are these bubbles just what happens with this finish, a problem with the materials, my prep, or with my technique? Do I just need to sand them down and try more coats?

I'm waiting on delivery of some oil-based grain filler (the current incarnation of Pore-O-Pac), as that has worked well for me before; so far I'm unimpressed with the Goodfilla. I also tried their powdered stuff in dark walnut, it was also way too light in the pores and looked horrible, though it did a better job of actually filling them.

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[Jim Becker]

That looks like a pretty heavy coat went on and maybe right over the grain filler..

You may want to consider using the EM1000 to seal and promote adhesion after your grain filler with the a waterborne topcoat. Since it's compatible with sanding, you can also level with a block, recoat, etc., to get those last little bits of grain filled, too. Wax free shellac can also be used including Targets unique waterborne version. I did a nice coat of the EM1000 today before spraying top-coats on that nice hunk of mahogany in my 'flat project' thread, as a matter of fact and sometimes use a little dye to tone things slightly in the direction I want to go. There's no need over bare wood, but there is "potential" mishigas with things like grain fillers which may explain the results in your photos.