Trailer fender rust

[gzecc]

Older trailer that I recently used por 15 on. Everything looks great except for the bubbling in the fenders. I would assume these are rust bubbles. Can I scape them down on the top side and use body filler on these? Or do I have to scape from boths sides ? Any suggestions? Not looking for show room condition. Just to stop the rust from getting worse.

 

[EatenByLimestone]

It looks like the por 15 didn't convert the rust. I'd sand it down, use phosphoric acid to clean all the little pits and then recoat with the por 15. I wouldn't use a body filler until all of the rust was gone.

Matt

 

[gzecc]

It looks like the por 15 didn't convert the rust. I'd sand it down, use phosphoric acid to clean all the little pits and then recoat with the por 15. I wouldn't use a body filler until all of the rust was gone.

Matt

I probably wasn't aggressive enough on the fender rust. I was afraid of making holes. Should I break and clean the rust bubbles, por 15 it , then body filler over the por?

 

[EatenByLimestone]

I'd break and clean it. Since it's a trailer I'd probably try to open it up with a wire brush, convert the rust and I think POR 15 is supposed to be fine over rust so I'd put it straight over the converted stuff. I think I read it can be thinned to different thicknesses? Maybe it can be self leveling and would partially fill a pit? If the trailer was going to be moving a nice, expensive car I'd worry about making it look pretty. If it's going to be a work trailer I'd let the pits stay. If the pits affect the structural integrity of the trailer I'd fix it so it was safe. The first time you go to toss a split into it and miss, it could dent the fender. You may need to fix the dent with a hammer.

I was looking at my boat trailer when I pulled the boat a couple weeks ago. It's been sitting outside since '87. I was thinking about removing the paint, converting the rust and then rattle can Rustoleum primer and then rattle can Rustoleum paint.

Matt

 

[gzecc]

My trailer is at least that old. I used gloss por 15 then flat black rattle can paint to cover the por. It came out great (except for the fenders)

 

[BobUrban]

Rust never sleeps! Sand/grind/wire wheel and convert - then paint or prime and paint but the cheap fenders will eventually rust. Up-side is trailer fenders are cheap and easily replaced if that ever becomes necessary.