Fiberglassing Rust Spots? School me on this please...

[UMT]

Ok, 99 Impreza Outback Sport. Getting all the typical Wisconsin salt on the roads rust spots. Mostly in the rear wheel well areas. School me on the use of fiberglass to repair..... Searched for threads and guys talk about it but not how to do it. Somewhat familiar with doing body work but have never tried to fiberglass anything... Seems better than 'ye olde Bondo treatment?????' Don't expect it to last forever.....

 

Thanks,

UMT

[porcupine73]

My limited experience is yes you can get a good result if you are patient and spend a lot of time sanding it and getting it just right. Otherwise forget it, it will be wavy and rust will reappear within the year. Bondo is a brand of fiberglass so if you 'bondo' something you are using fiberglass.

 

I will say this - be EXTREMELY careful if you use the pinhole filler. Damn I used that in the late 80's and got a few good whiffs of it. I didn't feel right later that day. My brother used the same stuff and said he didn't feel right either. I never fully recovered after that day, I don't know, something just seems 'off', but what can I do life goes on.

[UMT]

My limited experience is yes you can get a good result if you are patient and spend a lot of time sanding it and getting it just right. Otherwise forget it, it will be wavy and rust will reappear within the year. Bondo is a brand of fiberglass so if you 'bondo' something you are using fiberglass.

 

I will say this - be EXTREMELY careful if you use the pinhole filler. Damn I used that in the late 80's and got a few good whiffs of it. I didn't feel right later that day. My brother used the same stuff and said he didn't feel right either. I never fully recovered after that day, I don't know, something just seems 'off', but what can I do life goes on.

 

I didn't know that Bondo was basically fiberglass. Sure as hell didn't know about the 'pinhole' filler. Thanks for the heads up! I'm old and about dead from everything else going on in this society, but I didn't know about pinhole filler. Screw it. I'll put some naval jelly on it and let it rust. Ha.

 

Thanks,

UMT

[porcupine73]

Haha To be honest, the tact I've taken in recent years is to get as close a can of spray paint as I can, and then I just spray over the rust anytime it rusts through. Is it the ideal solution? No not at all. Does it look a little better than just big rust spots? I think it does, slightly, though the paints I pick usually don't match exactly so it looks kind of redneck. I had a friend in highschool who painted his car with 40 cans of 2/$1 spray paint. It was funny he would just do a little painting here and there for a few minutes at a time until it was done.

 

The thing about rust, at least in the rust belts, is you are seeing only the tip of the iceberg when you see the rust. To truly stop the rust, you have to get it ALL. If you leave a bit of rust behind the panel and then bondo over that, it wil just start rusting through within a year around the bondo edge. To get a nice smooth fiberglass that matches the body you really have to take your time and sand and level very accurately and then paint carefully. Else it is very noticable.

[CoupedUpSubie]

Either way the rust spots will come back. I just repaired mine in august. I cut away old metal and put new stuff in, sealed everything with a rust preventative. There are two types of bondo. You have the stuff with fiberglass in it and you have the smooth type. If you are filling large holes and need a decent amount of strength you use the stuff with fiberglass in it. The smooth type is for the last coat.

 

Just remember the rear bumper mounts in that area. I had to make new mounts to replace the rust that was there.