Best rear fender liner? - F-Body Road Racing and Autocross Forums

In the past, I've tried used several different rattle-can "rubberized" coatings consisting mainly of asphalt or vinyl. Neither is all that tough. The vinyl is a little easier to work except for some minor blushing issues (like laquer). The adhesion is probably a little better with the asphalt. Neither will dry completely if sprayed on thick, which isn't necessarily a bad property for a fender liner. However, I'm concerned that a thick enough layer of the vinyl (even built up slowly) may crack and allow hidden rust behind the coating.

However, in the past I've always been fixing a minor rub with minor hammering, padded by the original coating, that left the zinc plating intact. All I had to do was coat it with whatever was handy to prevent stone damage to the plating.

Recently I had some major rubbing on a sandy lot, with sand on the sticky tires definitely cutting through the plating. I also did some major hammering. So, now corrosion protection is a bigger issue. I already applied several coats of weld-through primer (first Wurth alu-zinc followed by U-Pol zinc, simply because I ran out of Wurth and can buy U-Pol locally). I definitely like the Wurth primer (even though no welding is involved) better than hardware-store cold-galvanizer paint. Adhesion is good on the Wurth, but I don't know about the U-Pol yet. Adhesion is poor on regular cold-galvanizer.

I'm thinking about trying a true catalyzed polyurethane truck bed lining, but that will be expensive and I'll have to waste most of it. I'm a little worried about adhesion (don't want to scrub the zinc primer too much), and it will be tough to repair if more pounding is needed. Brushing it on would be a big plus.

Thoughts?

sgarnett View Member Profile	Sep 29 2006, 01:38 PM Post #1
Seeking round tuits Group: Advanced Members Posts: 5,522 Joined: 24-December 03 From: Kentucky Member No.: 33	In the past, I've tried used several different rattle-can "rubberized" coatings consisting mainly of asphalt or vinyl. Neither is all that tough. The vinyl is a little easier to work except for some minor blushing issues (like laquer). The adhesion is probably a little better with the asphalt. Neither will dry completely if sprayed on thick, which isn't necessarily a bad property for a fender liner. However, I'm concerned that a thick enough layer of the vinyl (even built up slowly) may crack and allow hidden rust behind the coating. However, in the past I've always been fixing a minor rub with minor hammering, padded by the original coating, that left the zinc plating intact. All I had to do was coat it with whatever was handy to prevent stone damage to the plating. Recently I had some major rubbing on a sandy lot, with sand on the sticky tires definitely cutting through the plating. I also did some major hammering. So, now corrosion protection is a bigger issue. I already applied several coats of weld-through primer (first Wurth alu-zinc followed by U-Pol zinc, simply because I ran out of Wurth and can buy U-Pol locally). I definitely like the Wurth primer (even though no welding is involved) better than hardware-store cold-galvanizer paint. Adhesion is good on the Wurth, but I don't know about the U-Pol yet. Adhesion is poor on regular cold-galvanizer. I'm thinking about trying a true catalyzed polyurethane truck bed lining, but that will be expensive and I'll have to waste most of it. I'm a little worried about adhesion (don't want to scrub the zinc primer too much), and it will be tough to repair if more pounding is needed. Brushing it on would be a big plus. Thoughts?

slowTA View Member Profile	Sep 29 2006, 10:55 PM Post #2
Experienced Member Group: Advanced Members Posts: 2,290 Joined: 4-May 04 From: Kenvil, NJ Member No.: 331	If you have bare CLEAN rust or metal I'll recommend POR15, but you MUST clean the surface first. If you have rubbing issues then that small section should be down to bare metal so just hit it with some brake cleaner and paint (slather) with POR15. Read and follow the directions otherwise it wont protect as well. http://por15.com/