The good thing about this Brodak sealer is that it does a great job of filing the grain. Estes directions now call for 2 coats of primer followed by sanding and finishing with top coats. I think we all know that 2 coats of primer is not going achieve a nice smooth finish, it will take multiple coats, lots of sanding, big mess and added weight. I have tried priming only and it works but it also takes more work than 2 coats. I tried priming then filling with wood filler but even that ended up taking 4 coats of primer and a lot of sanding. Now I am sealing with 3 to 4 coats of balsa sealer, sands super easy followed by one coat of primer. I only spot sand the primer if needed but for the most part I don't even sand the primer before adding my top coats.
