robert_paulsen
+1y
ive watched a couple buddies lay mat and lay the resin over it, to my understanding of the process, its best to follow the directions on mixing ratios or it will turn into a hockey puck or a possible chemical fire. this stuff with to much hardener gets VERY hot.
basically if you can mix it you can lay it, it does itch like crazy when sanding so wear gloves, long sleeves and a mask.
depending on how crazy you get on reshaping the dash, consider looking into building a mdf frame like they do for subwoofer boxes, use fleece, a staple gun to secure the fleece, fiberglass (confetti) or the shredded stuff cant remember its exact name, or cut a mat into strips, coat both sides of the strips then lay it down on your area your reinforcing. the fleece once coated in resin gets nice and hard but reinforcement of a layer or two never hurts.
if your attaching to plastic rough it up really good or it may not stay attached long term.
if your just modifying the dash like shaving vents for the defroster, or other items,ive seen people take a epoxy after roughing up the area and attach a filler panel from plastic, plexi and even mdf. ive seen filler panels get epoxied into the dash to fill areas then sanded smooth, body filler if necessary for additional smoothing then sanding the entire dash spraying a bulldog adhesion promoter for plastics and then primer and paint. just remember something like a 40 grit is a bit rough or excessive unless your planning on using multiple coats of feather fill on the dash.
in most cases you can do alot of things in many different ways but what you want done will kind of dictate what you want done. fiberglass is prone to cracking so reinforcement is never a bad idea.