Can you use Isopon?

[The Griffalo]

As the question says really, can you use regular body filler on fibreglass? I've got a couple of small screw holes that need filling now I've cut my front plate down

If I can't use regular filler what should I use?

[Stu R]

Yep just try and get the fibreglass fairly smooth and even so the filler isn't too thick

[AluminAl]

You`ll be fine with any of the "easy sand" fillers,although do try to back up the holes with a thin layer of matting,ie don`t,if you can help it, rely on just the filler in the hole.
Sometimes it`s not possible to access the rear of the panel,in which case countersink the edges of the hole for better filler purchase.