Stain Problem/Question

Building a bookshelf (80LX32HX11W) for one of our local seniors as part of my volunteer activities (Plain-O-Helpers, we work for free and supply materials from contributions if the requestor can't afford it, as many can't).
Because the lady doesn't have much $, I used HD handy panels which are junk, but look OK on the surface wood. She wanted a "dark stain" but when I met with her and showed her some samples of the panel with various stains and poly overcoat on them, selected MinWax Red Mahogany as her preferred shade. She has a bunch of really nice old furniture - walnut, mahagoney, teak and a burled maple cabinet that I'll try to get a pic of - it's glorious, so the mahogany wasn't out of place.
I've done all the cuts, dadoes, and rabbets, etc. Masked glue surfaces and began the staining yesterday. Applied MW stain conditioner to minimise blotching 'cause the Handy Panel surface wood is really soft. Waited 2 hours per instructions and applied MW Red Mahogany oil stain (from a brand new quart), waited ~10 minutes, wiped off with blue shop paper towels. I didn't try to rub off the stain, just wiped until the surfaces didn't look wet. If I'd wipeed more or harder, ther would have been additional stain on the towels. Instructions say to dry for 8 hours, so, in an excess of caution I thought, I let all the pieces sit from 1300 hours yesterday to 0900 hours this AM. I then applied a coat of MW poly (semi-gloss) that I had thinned about 5% with MS (1/2 cup in 3/4 qt). Not a heavy coat, but not wiped off either, just enough to leave the surface looking wet. It went on fine and the foam brush didn't turn paint thinner colored when I dunked the foam brush into it to clean up after finishing.
I went out about 30 minutes ago (after ~2 hours of drying time) and, oh my gosh (or other similar words), I've got little pimples of dark stain rising in the poly. Like measles, pin head sized, but dark ones, darker than the surrounding stained wood. Now these are the inside sides of the shelf carcass and I figure after I hit it with 220 grit and apply another coat of poly, the problem won't be noticeable on the finished piece. I would, however, like to avoid it on the outside "show" parts.
I can only assume:
a) I did not wipe off enough of the stain so it didn't dry adequately
b) I didn't give it enough drying time
or both.
The drying environment was about 80 degrees F and RH has been around 30% for the last 24 hours (Thank you Lord for a N Texas cold front in August!).
I know there're a bunch of finishing gurus out there 'cause I read your posts. Any bright ideas to avoid a repitition? I mean it's just a volunteer project, but I like to do it right (or as right as my limited abilities allow).
Tom
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Tom B wrote: ...

...
Don't know what the actual wood is and not familiar w/ what you're calling "HD handy panels" (no HD's within 200 miles) so guessing a little.
My conjecture is this is a porous wood like oak/luaun/similar and there was stain captured in them that wasn't entirely dry even though the surface appeared so.
I would expect a rubout a little more and additional drying time will solve the problem. Alternatively, a cut shellac coat before applying the varnish would stop the telegraphing.
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dpb wrote:

I have to nod my head "yes" when reading this response. Before proceeding further I would suggest testing your original method (of following the instructions) modified by the proposed solutions on a scrap piece of the same wood. You want to eliminate the surprises before forging ahead on the final product.
As far as my proposed solution: If this is indeed porous wood, I *always* follow up the wipe-down by blowing the stained surface with compressed air, then wiping away any additional stain that weeps out of the pores. You'd be surprised how much stain something like red oak can collect in the pores, and you'd have to wait far longer than the suggested drying time for that to cure fully and not come seeping back out when you try to apply the top coat.
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Tom B wrote:

1/2 cup of mineral spirits added to 3/4 quart of poly would be 4 oz/24 oz, closer to 17%. I'd suspect the added mineral spirits lifted the stain.
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Jack Novak
Buffalo, NY - USA
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Guess I had a brain seizure when I did the mental math.
As I often thin poly by 20% (when I wipe it), I didn't think it would be a problem. You may well be right. I rarely use stains in my finishing because most of my work has been in woods where I want the natural wood color to show. This one was an "on request" type thing using inexpensive materials.
I think a wash coat of de-waxed shellac after the stain has dried may be in order on the rest of the surfaces.
Thanks.
Tom
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