Hey Dan, some good advice here.
I just went digging and found this... I wrote this a couple years ago on another forum, and it pretty much covers how I brush on WB poly:
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I have been using Flecto Varathane WB clear finish on my projects for 10 years and never had any dissatisfaction with it. Granted, I am a hobbyest, not a pro, so 10 years isn't a huge number of projects. But the fact remains, the product is fine.
I tend to always use a foam brush. And like has been mentioned, you must NOT try to "work" the finish. Dip the brush, hold it over the can, letting the excess drip out (do NOT wipe on the edge of the can, that makes it foam up), and then spread it on the project. You can go back over the finish MAYBE once, to make sure it is spread out, but that is it. You cannot keep working it.
Make sure your area is well lit with angled lights, so you can see the "dampness" of the finish, to ensure that you cover all the areas. I find I lean over a lot as I apply it, to ensure that I see it is covered.
The first coat is always the worst. The wood sucks it in, and it takes forever. It also raises the grain and feels rough. So after the first coat, I go over the project with some 220 grit paper wrapped around a sanding block. One or two light passes and it will feel much smoother.
Then again, with a second coat, another extremely light sanding inbetween - use worn 220grit, just lighly touching here or there where you feel roughness.
Usually a third coat also. You'll find that the 2nd and 3rd coat go much quicker, as you can spread out the finish much further.
Yes, there often appear to be lots of bubbles... I have had to train myself to mostly ignore them. They level out on their own and go away as part of the drying process.
Finally, after the 3rd coat, I'll dribble on a little water -- just a few drops -- and polish it up with a synthetic #0000 3M pad.
...art
ps: my shop is in my basement, so it is in conditioned space, warm in winter, cool in summer.
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in addition, Like Larry said, red oak with the pores is tough. I almost never use red oak, so I did not mention it above. A few months ago I did make a shelf with red oak and I wish I had used a sealer on it, I had 5 coats on it and it still was not as level as I'd like.