Wheel well undercoating? What worked for you?

[Rusty76]

So I had a plan all set in my head on how I was going to fix the rust in my wheel well and inner 1/4's. Started reading the internet now its paralysis by analysis.

I welded in a lot of new sheet metal on both sides in the inner quarter section and floors in that area. This was/ is my plan to seal up the wheelwells.

Duraglass over the welds in the wheelwells, chassis saver ( same as POR15)the whole area, rubberized undercoat. Now I'm thinking I should prime the new and old metal with epoxy primer first. Then duraglass welds, chassis saver and rubberised undercoat. I'm worried that I will either be putting epoxy primer over some surface rust or I will be putting chassis saver over too clean metal. This is not a show rig. Family adventure, hunting wagon but still would like some longevity. Maybe I need to keep cleaning up the area to perfection and use the epoxy primer? Not super rusty but some spots will be really thin once I get to bare metal. In the process of painting the rig and this is the first step. Thanks
IMG_0017 by , on Flickr
IMG_0015 by , on Flickr

[Rusty76]

Thinking about it a little more. Maybe its just not a big deal either way.
The factory coating did a pretty good job for 43yrs.

[Tripwire]

nice patching i would use eastwoods coatings and stay away from the rubbery stuff

steve

[threepiece]

Avoid Duraglass or any such product that contains polyester in the wheel well area. Polyester will absorb moisture if given the chance. The result will be rust on any steel it is on.

I like sandblasting (not actually doing it, I like the results). If you can somehow manage to blast the openings I would then spray epoxy primer. If the metal is pitted I will telL you that two coats is not enough. Four to six coats is my minimum on rust pitted surfaces.

I also like to thin the primer for the first two coats. This helps reduce the surface tension so the primer will flow into the tiny craters easier.

If you are using a brush to apply allow enough time between coats for the primer to firm up. Applying too soon will soften the previous coat and you will not achieve sufficient build thickness. The idea here is to burry the rust pits deep in primer.

Following this you can put anything you like to get the look/impact protection it deserves, even Duraglass.

[Cliff]

I just did my wheelwells using Eastwood Rust Encapsulator on the rusty spots (after treating and sanding) then top-coated it with ordinary Rustoleum. I just kept is simple. And both paints have been very good to me. I use foam rollers to apply Rustoleum and it looks like it was sprayed. I had quite a bit of surface rust but no holes.

I was considering a bedliner type material and top of the list was Durabak. But it's not cheap. I have used it before and it's really good stuff. It's a polyurethane.

[babywag]

Standard prep and real paint. Then "undercoat" anything less will likely result in rust frenzy.

[Rusty76]

Thanks for taking the time to reply. I wish that was my patching. The work I did is on the outside/inner well. Dog leg and around the wheel well. I can best describe it as lap weld frankenstein. It's really ugly but will keep the water and muck from getting the new dog leg and quarters. The easy way would have been build inners before I welded the 1/4's but live and learn..

My understanding is that a guy should cover welds with either kittyhair/duraglass or seamsealer to keep moisture out. After the primer.This is what I've come up with.

4-6 coats of epoxy primer, duraglass over the new welds, 1-2 coats of epoxy to seal the duraglass. Followed by chassisi saver and finally spray can rubber coating. I do have a couple epoxy 2part spray cans but I think I will just brush it on. Thanks again for all the great tips. keep you posted

[threepiece]

Fiberglass reinforced body filler is recommended for areas that lack stiffness. If you have welded new metal using it is not economically wise.

With any polyester filler product a seal should be made before and after application to prevent infiltration of moisture from above or below.

[SJTD]

Polyester isn't the problem. Lotsa direct to metal primers are polyester.

It's when it has a filler that makes it porous like Bondo that it can allow rust. I dunno if "kitty hair" that uses glass fiber as a filler fits that. I suppose better safe than sorry.

[SOLSAKS]

my opinion....tho not worth much,...

but I like the EASTWOOD products

like the rust encapsulator tripwire mentioned

but even if you used
either rustoleums self etch primer, or just regular rustoleum red oxide primer
then their high performance enamel top coat to seal it
it would be fine

the rubbery undercoat that you could put on last
will help sound deadening a little
and prevent top coat paint from chipping.

nice work on the repairs.

dave in NC

[rang-a-stang]

I just pressure washed my wheel wells, gave the surface rusted spots a fairly thick coat of Loctite Rush Inhibitor (let it cure for a week), then a fairly thick coat of Rustoleum 2X flat black, then a fairly thick coat of the crappy Harbor Freight Rubberized undercoating. Like you said, the factory coatings were good for about 20 years so this process will likely last another 30.