I have looked and found answers both ways on my issue about using bondo to fill imperfections on my plastics after I welded them. I also welded the 3 pieces of the tail into one piece. Please help

 

The majority of the finishing is just holes and stuff that look like white specs in the pics (because of sanding dust) bit there is a few low spots that nees to be raised so its not like im globbing bondo on to make a part or fill a gaping hole.

 

...so what was the question? A larger area of filler in a flexible fairing part can and will develope a crack between the two over time but from what I could see in the pics they don't look that bad.

 

My question is can I use bondo to fill the pits and the low spot or two (that developed from sanding)? The bondo would be more of a thin skim coat, or do I need to find a plastic style "bondo" filler?

 

If you're unsure go find a professional car painter for an opinion. A picture is always a picture but from what I can see you should be fine. Just use some fine grit car body filler for finishing, no fiberglass stuff as it will be rock hard when dry and all the fibers are sticking out in every direction so it is not a finishing product. Remember "what the finger can't feel the eye can't see" meaning if it looks straight but when you run your hand across and feel a dent it will show once shiny.

 

Use " finishing gaze" ic your local autozone,or advanced auto parts store has it. Its pre mixed bondo, and it doesn't " stain or leak through" your paint finish. Also easier to sand.So does sealing your primer!

 

I've used it on plastics, spray putty as well. Came up good and still holding.
A pro would probably say not to use it.


Edit: a lot of those scratches will sand out once you prime it.

 

Its not the scratches that im worried about they came out with 800 grit wet sanding. Its the pits and a low spot that I want to finish out. Can you use finishing glaze to level off a low spot? Im aware that it will fill the pits from welding and I have thought about using finishing glaze just wasnt sure just what the extent of its use was.

 

Hiya

Have you tried bumper filler? It's a flexible bondo for use in plastic car bumpers - have a look at this - Halfords | David's Isopon Bumper Filler 100ml - then have a rummage in your local auto parts store for a Stateside equivalent.

I've stitched/glued/welded/glass-taped some mangled '88 plastics back together and faired the frankenstein-esque scars with this stuff and it's pretty good - nice smooth finish, sands predictably and controllably (just don't go ape with powersanders though - it gets hot and claggy) and seems to 'breathe' with the original material well enough to keep the paint where you're sprayed it.

Lets us know how you get on?