Hi Chris,
I wouldn't prime with a deglosser. For one thing, you might have mysterious chemical adhesion problems, either with the ABS/primer bond or the primer/oil paint/medium/varnish bond. (Heck, this is all a mystery.)
Most importantly, though, it would affect absorbency. I just completed another little painting in which I used a sanded Masonite/Gambin Oil ground board, which had almost no absorbency. In fact, it seemed to almost repel the paint. I fought with that painting every step of the way; this ABS panel seemed to paint itself.
You are, like me, a big panel user, so I'll get one of these over to you to try.
Here's a closeup:
|