Tips on applying polyurethane clear gloss varnish onto plywood?

i have tried this before but has not come out as better then expected. I have also used a good quality brush but i want tips on how to get a perfect finish on applying a polyurethane clear gloss finish onto a plywood piece.Tips on applying polyurethane clear gloss varnish onto plywood?
Sand between light coats with progresively finer grit sandpaper.


Allow ample dry-time between re-application.


Don't glop thick and heavy coats on, go slow and easy.





Good Luck!Tips on applying polyurethane clear gloss varnish onto plywood?
you have to sand each coat, use a very fine sand paper, after each coat has dryed, then wipe it down with a damp cloth, [this is called tacking] it removes the dust, don,t sand the last coat, we use 3 coats,


if you are staining the wood first do the same to the first coat of stain, then give it another coat of stain, sand, tack then polyurathane it,
The brush is the most important part, and secondly using a good quality poly is important also. Don't be afraid to put on plenty of product. A good poly should level it self out. Avoid over brushing. I like to build up a film( 2 coats) before I sand, and then lay out the final coat.
1. Thin the varnish, even though the can may say not to. I thin the first two coats 50-50, third coat 2-1 and the later coats at least 10%





2. Sand between coats with P400 paper. 3M's 216U is great stuff.





3. Put on as little as possible consistent with complete coverage. The biggest mistake I see is people putting it on too thick.





4. Don't over work the wet varnish. You are not painting a barn. Slow, steady strokes. When you are done with an area, ';tip-off'; by lightly taking an unloaded brush and while holding the brush nearly vertical and with minimal pressure, make long, straight strokes across your work.





5. Pour your varnish is a clean container and work out of it. Don't work directly from a can as you will introduce contaminants in the finish. If you have any left in your can when you are done with a coat, throw it away.





6. Use a high quality natural bristle brush. I prefer ';badger hair'; for at least the later coats. They run about $20-30, but mine is 20 years old and works well. This will be the best $20 you will ever spend.





7. If you have a choice, apply the finish to horizontal surfaces.





8. Work in a clean, dust-free, environment. Once you have applied the varnish, leave. It will pick up and hold anything that lands on it for several hours.