Resin over MDF?

Fiberglass mat is to add strength to a surface that has no such thing. (Ex: Fleece stretched to MDF rings that has nothing but fleece, this is obv not gonna work, you need something to make it a solid strong surface, adding in glass mat/cloth does that.)

I am not even sure if you need the fleece for the resin, wood is pourous as hell, should soak in fine. But I don't have enough box experience to be reliable and I'd suggest waiting for a support by someone that has good knowledge.

if youre looking to strengthen the box up add some ribs on the inside " brace it ", using fuberglass in that maner will not add as much strength as you think, i say again brace the inside of the box!

if youre looking for a glossy finish on the box, you still dont need to fiberglass, just sand, bondo any inperfections, sand some more, prime and paint.

thank you very much all, you have answered my question. We just wanted a smooth paintable surface and used the fleece for a few small contours is the reason we didn't just resin the mdf. I'll hopefully have step by step pics in the next day or so!

Drew