I've seen MDF take paint like a mofo due to not being sealed properly. Do you mean the particleboard? That seems more porous than MDF - which is known for being a pain - so the particleboard would likely be a thirsty bugger. Some seal MDF with a 50/50 glue and water mix that seals things up very well. I suppose that is why most cabs like this are vinyl covered? Curious what kind of primer you used before painting... I was gonna roll, now I am worried
Seriously coming together nicely tho Chance, and at a good pace. I would definitely prime/paint that CP as I reckon over time the corrosion will creep under the laminate fairly easily. That said, it may be fine and not lift the art. I recently stripped a seemingly fine filing cabinet and was shocked at what the bare metal looked like underneath as it had a fair deal of corrosion starting, with little hint from the paint on top.