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I made my daughter a sofa table and used a wash coat of shellac and 2 coats of Arm-R-Seal on it. The bottom looks fine but the table top had lots of brush marks on it. I used a foam brush to apply. Not at all happy with the look of it, I sanded it down a bit to reapply. I watched Jeff Jewitt's YouTube on applying poly with a paper towel so I put two more coats of it on that way. Same result. I am about to sand it again and apply Crystalac that I have had great results with in the past. I see many users on Woodnet use Arm-R-Seal and they really like it, which caused me to try it in the first place. Before I spend another $30 for a quart of Crystalac, any suggestions for what I may have done wrong and how to fix the Arm-R-Seal? Thank you as always...FPT
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I've never been able to get a good result on a large surface with a foam brush, though I know others have. I might use it for the first couple of coats because you can apply it more heavily than wiping, but I always wipe on the last couple of coats. The best results I've gotten with a foam brush came when I thinned the ARS about 25% with mineral spirits, then flowed it on with the foam brush so that it could self level. This only works on a horizontal surface; on verticals it will run. When I had 2 or 3 coats on I sanded it with 400 or 600 grit until it was flat, and then applied 2 or 3 wiped on coats. I use blue shop paper towels. The key with wiping it on is to work quickly and don't go back over it. If the RH is really low it's extremely hard to get it on w/o it starting to set up before it levels out, and when that happens you will get streaks. So in that case, add 20-25% mineral spirits to increase the working time.
It's also really hard to put on satin sheen w/o streaks. I've found it best to use gloss for all the base coats and satin only for the last couple of wiped on coats.
John
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Just sort of repeating what John said: I've not ever been able to use a foam brush for a finish and have it work well. But I think the real problem may be you need to thin it a little more.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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Remembering how it was (viscosity) when I put the top coats on, I think both of you are bang on correct. The foam brush dragged no matter how much or how little product I applied. The dragging as I am calling it left the streaks and the product never "sat down" or leveled out. I do want to be able to use it since others use it and like it, but I need to know when I am done with all that work, it will look great. Thank you as always.
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Yeah, if the brush is dragging and that's what's creating the streaks, you either aren't applying enough so that it can flow out or it's drying too quickly. Thinning it will help. I remember Richard D. describing that he loaded his foam brush to the point it almost dripped and let the finish flow on from one end of the piece to the other, and that was a pretty large dining room table. Then he loaded the brush again and took the next, adjacent pass, with just a hint of overlap. He was very clear about not going back over what had already been done.
John
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I do get even coats with a foam brush and I have two techniques for doing so. The techniques apply to oil based poly only.
The first is just to apply a heavy coat on horizontal surfaces and let gravity level the finish. This builds finish thickness fast but leaves a finish that looks slightly plastic-like. But three heavy coats that are allowed to fully cure yields a surface that is very, very tough.
The second method is sort of a wipe on method. I apply a heavy coat and let it sit for a couple of minutes and then using paper towels I squeeze out most of the finish from the brush and using just the weight of the brush I draw it across the surface. This yields a build that is less than brush on but heavier than wipe on. It is fast and easy to do with oil base, but water base dries too fast to do this. On oak it allows the grain to remain.
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