best filler for fiberglass?

[chopthebass]

What's the best body filler for small repairs?

I made a stupid mistake and have repaired with mat and resin from the rear, but need to fill to match the body shape.

I can readily get Bondo products. Would they be any good?

[mikeinatlanta]

The FFR body is made from glass and vinylester resin. Fiberglass repairs should be made with vinylester. If you are needing a high strength filler there is only one vinylester based structural filler on the market, and that is 3M High Strength Repair Filler. It is a marine product and not carried by any of their automotive suppliers, so you will need to buy online or seek out marine suppliers. For non structural body fillers I'll leave it to the painters, however, overall you get what you pay for and 3M Rage Gold is very popular.

EDIT: If the repair is already made from Bondo branded resin, it is already far inferior to the original material. I recommend either adding 50% thickness or removing it and using vinylester. Using vinylester structural filler over a polyester repair will be of no value, so go with whatever is cheap.

[UnhipPopano]

Chopthebass identified the repair to the gel coat as being small. Mikeinatlanta would be correct if the repair needs to be more extensive than a crack or an area lager than a half dollar. For the smaller fixes, epoxy gel coat and cellophane is the way to go.

[chopthebass]

Thanks Mike. Its non structural, and just to repair my over cut on cutouts for louvers. Can't source 3M rage gold here in Canada.
Found Evercoat 112 Rage Gold Premium. Not sure how that compares.

[mikeinatlanta]

Chopthebass identified the repair to the gel coat as being small. Mikeinatlanta would be correct if the repair needs to be more extensive than a crack or an area lager than a half dollar. For the smaller fixes, epoxy gel coat and cellophane is the way to go.

Based on the statement of mat and resin being used, I made the assumption that the repair needs structural integrity. Not to make to big a deal for a small repair, but you should never use epoxy to repair a vinylester laminate. Use either polyester (original gelcoat material) or vinylester (original laminate material), but never epoxy.

[Jeff Kleiner]

...Can't source 3M rage gold here in Canada. ,
Found Evercoat 112 Rage Gold Premium. Not sure how that compares.

Rage Gold IS an Evercoat product, not 3M! Be sure to bevel and feather out your overcut edges before using filler so that they don't picture through over time.

Jeff

[mikeinatlanta]

Rage Gold IS an Evercoat product, not 3M! Be sure to bevel and feather out your overcut edges before using filler so that they don't picture through over time.

Jeff
Oops.:o That's why I leave bodywork advice to the painters. Very clear line where my knowledge ends.

[chopthebass]

Thanks guys. I have a better understanding now.