I am applying a top coat to my MDF bookcase. This has had 2 coats of MDF primer.
I have a Valspar Satin mixed colour for my top coat. When I apply this with a foam roller (exact approach I used for 2 coats of the primer), I am getting lots of small bubbles.
Applying with brush doesn’t cause this issue.
I don’t want to go any further until I know what’s going on.
Can you please advise as I am now downing tools

I have a Valspar Satin mixed colour for my top coat. When I apply this with a foam roller (exact approach I used for 2 coats of the primer), I am getting lots of small bubbles.

Applying with brush doesn’t cause this issue.
I don’t want to go any further until I know what’s going on.
Can you please advise as I am now downing tools