Rocker panel coating loose

The coating on the bottom of the RHS rocker panel on my 02 has cracked and come loose from the metal (about one foot of it). Was wondering if it could somehow be "glued" back in place or would that be a bad move as it would be hard to get a water tight seal and water, road salt etc might become trapped inside?

Maybe better to cut off the loose stuff and repaint the exposed metal??

NoSmoke said:

Maybe better to cut off the loose stuff and repaint the exposed metal??

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Yes, but...keep in mind that the "exposed" metal may be in worse condition than you think it is.

I had the same issue with my Golf last year...the paint was peeling away right at the bottom of the rear fender arch on the right hand side. When I looked close, a few inches of the rocker guard coating was loose from the body.

I cut the old rubber/paint off with a utility knife, then sand blasted rust away, coated with a self-etch primer, then rocker guard, then painted with VW matched base/clear. It's been through a Maritime winter since and is still holding up fine.

It passes the 20/20 Rule, that is it looks good from 20 feet at 20 mph.

Thanks, that looks like the way to go alright. Looked up rocker guard though and found a large disparity in price - $11 at Canadian Tire to $80 on amazon.ca (which seems like a ripoff). Was wondering what you used and what you used for the primer?

NoSmoke said:

Looked up rocker guard though and found a large disparity in price - $11 at Canadian Tire to $80 on amazon.ca (which seems like a ripoff). Was wondering what you used and what you used for the primer?

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Canadian Tire is fine, but they have a couple different rocker guard products...one of which doesn't dry...which you don't want for this type of work.

I used this stuff below...I think it was around $7-$8 on sale at Napa, and it dries quick.



The primer I used was "Self-Etch Primer" which they likely won't have at Canadian Tire, but will have at Napa...again, should be $10 or less I think.

If you go to a proper auto parts place with an autobody section...like Napa, or Carquest, etc...they will have the stuff you need, and staff that know a little about whats on the shelf.

OK, went to Can Tire and bought a can of "Rubberized Rockerguard Undercoating, 830 ml Schutz Black" (comes in a non-spray can which I gather is supposed to be sprayed using a Shutz spray gun, whatever that is).

<http://www.canadiantire.ca/en/pdp/rubberized-rockerguard-undercoating-830ml-shutz-black-0477937p.html#Questions>

I bought it instead of a spray can as it is a lot thicker and will apply with a brush. I trimmed off the loose undercoating which exposed quite a bit of mainly surface rust so cleaned it off as much as I could with a hammer and wire wheel. Instead of a primer, I applied a coat of Tremclad Rustpaint. When that dries, will brush on a couple coats of the Rockerguard and see what happens.

That should work.

I think there are a lot of Mk4 VW's getting Tremclad touch-ups these days...my 03 Golf included.

Thanks for the help Rembrant. I hope the stuff I bought at Can Tire is not the one that doesn't dry.

I'm not familiar with that stuff, but it's probably fine. I'm sure you'll let us know.

I was thinking of the Asphalt undercoatings...it comes in two versions...one is rubberized, the other is not. If I recall correctly, I think the non-rubberized stuff stays kind of sticky/tacky...

http://www.canadiantire.ca/en/pdp/rubberized-asphalt-undercoating-0477904p.html

http://www.canadiantire.ca/en/pdp/asphalt-undercoating-0477999p.html

Took another look and it says it's paintable after drying so it sounds like it will be OK.

Brushed on the Canadian Tire Rockguard stuff and it seems v good - much thicker than spray stuff and drys quickly (Smells like toluene solvent so you have to work fairly quickly).

Trouble is though, further inspection of the rocker panel at the back end showed a lot more rust with several rust-throughs. Was able to airblast most of the dirt out from inside the panel and spray paint the inside but am wondering now how to plug the holes. Was thinking injecting expanding urethane insulating foam through the holes and covering everything with the rockguard might work for a while at least (mickey mouse I know and the panels should ideally be replaced but I don't have the wherewithal to do it myself and having it done by a body shop would likely cost a lot more than the car is worth).

Any ideas would be appreciated...

NoSmoke said:

Trouble is though, further inspection of the rocker panel at the back end showed a lot more rust with several rust-throughs.

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Is this car from back east?
I didn't think that they got that rusty out west.

Rust is always worse than it appears to be. There is a Mk4 Jetta at my wife's work that is full of that spray foam insulation...lol. You can see it in all of the holes. Looks like it was used to fill them a while ago and the car has rusted worse since.

I've never done it before, but I think it will work OK if all you're trying to do is fill the holes enough to apply some rockerguard rubber coating over top of it.

A friend of mine used to use that expanding foam spray to fill rotten rockers. He'd carve it with a knife once it dried so that the contour matched the car. Then, he would apply fiberglass and filler over top of it, and paint with a rattle can. It wouldn't win any car shows, but it made the car "hole-free" enough to pass MVI, which was all that mattered anyway.

Not from back east, bought and driven all it's life in Calgary. We don't use quite the amount of salt on the roads that's used in Ontario & Quebec for example but older cars do certainly rust - all the cars I have owned here have had rust problems after 10 years or so. I guess I'll have to move to Arizona... I also probably should have looked for the rust sooner and done a little more PM.

Anyhow, yeah, my idea was to fill the holes with foam and maybe put some filler & paint/rockerguard over it. I'm thinking filling the inside with foam might also help prevent future corrosion from inside but maybe it would only serve to trap water that would have otherwise drained or dried out(?). I'm not too concerned about appearances as the rust is all on the bottom of the panels so the repairs would not be normally visible.

Oh well, I bought a new set or tires a few days before I discovered the extent of the rust damage so it looks like I'm committed now for better or worse.

Filling the "inside?"

Foam is not a good idea because it holds moisture. I realize that you're likely talking about spray foam, but VW had shelled out a LOT of money for repairs for damage done by foam inserts on the tops of wheel wells (inside edges): they've also taken care of a lot of other rust, but this was biggie that they jumped on because it was a bad decision.

VW used wax oil on the inner rocker panels. I recently cut some rocker sections out of a parts car (PNW car- it was spotless) and could see that they didn't skimp on it (pretty slimy stuff). The rocker sections were for my Golf that I got from Minnesota; body shop put new end caps on with epoxy in order to not melt away (as it would via welding) the protective film.

There are "open" cell foams and "closed" cell. The open cell will absorb and retain moisture while the closed cell, such as expanded urethane foam insulation (which is what I used) should be OK in that respect (I hope), And virtually nothing will dissolve or interact with urethane foam after it cures (other than high temperatures) so it should be stable. It also sticks like sh*t to a blanket to almost everything which should serve to keep it in place.

We will see I guess - I know it's a mickey mouse solution and hopefully will last a year or two as I don't see the utility of putting a lot of effort and $ into a car that old (it might be different if I could do proper bodywork (and the bigger mechanical stuff) myself though).