Start with a high-quality natural bristle brush and you’re halfway to a smooth finish.
As with anypaint job, preparation is the key to success.
A finish will only be as smooth as the wood underneath.
After you have a smooth surface, you’re free to start applying the varnish.
double-check you are in well ventilated area that is clear of dust and other airborne particles.
For the step-by-step instructions on perfect software, check out the link below.
How to Apply Polyurethane| The Family Handyman
PhotoGlenn Rice.