General Finishes High Performance Poly...Had some troubles with it

[Don Morris]

I read the specs, followed the instructions, ended up with some ridges (in line with the grain and direction of application) and occasional bubbles in them, when applied with a sponge applicator on highly figured cherry after 5 coats. Some slight ridging and bubbles showed up at around the 3rd coat. It looked like it needed the additional coats. What did I do wrong?

[Phil Thien]

You may have worked it too much. Water-based products don't take to excessive brushing. It is pretty much get it on there and leave it alone, it will self-level quite quickly. It also tacks quite quickly.

What I've done with other water-based products is mist-on real Windex (there are lots of glass cleaners, I'm talking about real Windex blue stuff) right after the final coat. The Windex trick will give you a very nice smooth final coat. Of course, this only works for horizontal surfaces or surfaces that can be made to be horizontal.

I've not tried it on the General Finishes products, though.

[John TenEyck]

What was the temp. and RH? Did you sand between coats and, if so, with what? I've never had that problem with GF HP Poly, although I normally spray it, and have never brushed on 5 coats so that's new territory.

John

[Don Morris]

It's in a basement shop that's well heated and good RH. I lightly sanded in between with 220. On some areas of the project, it's beautiful. There are some other areas that the problem is more evident. Now that I look at it more critically, more in the areas where I probably got it on too thick. But I thought I followed the instructions fairly closely. I see where most of you spray it. That's not going to be possible for me.

[scott vroom]

Don, are you sanding with a sanding block between coats? It's a good idea particularly where you have subtle ridges.

I think Phil may have nailed it on over-brushing. Poly will self level nicely, no need to work it....just brush it on one pass then the next row etc. If you see a tiny bump don't go back and re-do....keep going and sand it down between coats. WB poly dries fast in a warm shop...it's not like oil paint.

You might want to practice on a small piece of scrap