re: polyurethane application

For my own best results, here is how I apply poly. 1) sanding the wood down to 320gt, 2) apply the colour stain and wipe it as evenly as possible, 3) apply a thin coat of sanding sealer and wipe away any bubbles or drips, ) applying the poly, conditions are key, you should have low humidity and warm temperature. The manufacture adds dryers and levellers but you can add your own in the base coat to help. You may need to do some research to find the ones that work with your product. In one case I even added gasoline to add a fast dry and good level to a poly. 5) the method that you use to apply the last couple of coats must only put very thin coats on, I usually thin the product even if the can says not to, and spray just enough to know it was sprayed all over, wait an hour and repeat until the entire piece looks wet. Wait 24 hours, light sand and continue with step 5 until the piece looks finished, sometimes with high humidity it has taken 5 days to get the right results. Then 6) after drying a couple of days apply a finishing wax with the shine/flat type of finish to give the shine you want.
I know everyone has different methods, this is what has always worked for me. In my shop I keep a binder of every pieces finish. It includes every material used times for drying, application method, and shininess. It also lists overall results. It makes repairs easy, and helps to find the finish that work best for the various styles of pieces I have made. It’s a 4" thick binder and is almost full but it’s a wealth of knowledge when I go to finish a similar piece. I had started doing this when working in a CP hotel & convention center so that repairs were made easier, I just follow it up with one in my own shop.