subbox

So I want to paint my sub box. I know that mdf absorbs paint so I know I have to put a layer between the paint and the wood. I was wondering if I should get wood sealant or a primer paint? If I should get a wood sealant can it be any kind?

ok i have 2 ts-w3002d2 subs andno idea what to use for a box i wana make one but dont kno if i should go ported or sealed and what to do for ether when i decide i want ported but dont kno if its the best way to go and if i need help making planes i dont want the box to be carpeted just painted...

My project after a couple layer of fiberglass