The Stovebolt Site Forums The Shop Area Paint and Body Shop Cab corner rust prevention

Hi All,

For some fortunate reason, I have very solid cab corners on Gramp's 51 P/U. I would like to keep them that way. I stuffed the sandblast nozzle down into that dark abyss behind the seat and am satisfied that I have cleaned the area very well. My concern is getting a new coating in there and getting as much coverage as possible.

It would seem that spraying would be less than desirable due to air vortex issues. Since the area behind the seat will have an undercoating for the final finish I do not care about the quality of the finish I apply. I just want the metal to be as protected as possible. I'm leaning toward a rag stuffed down in there with epoxy primer on it. Has anyone else tried this method?

Thanks

On my 46 I used a very wet brush and let the primer run into the cracks. Let that sit for a week then repeated with exterior color coat. Then filled with urethane spray foam. Then sealed the top and cab back skin to floor pan with urethane auto crack,gutter calking. Then I primed and painted the cab interior. Then I used two different sealers when I installed the rear window.

Thanks GW. Sounds like a permanent fix.

If it's solid after 60 years why are you worried about it? You
planning on living another 60 years?
There wasn't all that much paint in there even when it came from
the factory. The secret to the longevity of those cab corners
is that the drains have been kept open and no one stuffed old
rags, mud, extra socks, left hand gloves and what'all down
there that could hold moisture.
I would just use a 1" brush dipped in the paint cup right before
you shoot the inside and swish it around in there. Taint all
that tight or deep of a pocket.

Denny Graham
Sandwich, IL

Thanks Denny. My plans are to give the truck to my 13 y.o. daughter when she gets her drivers license so yeah, I plan on it lasting another 60 years. It was originally a California truck but is now a Colorado truck that will be a daily driver and we use mag chloride here - if you ask me, too much now that people have forgotten how to slow down when driving in inclement weather.

Keeping the drains open does seem like the most logical thing to do.

Thanks

Anything that will absorb water, be that a rag, dirt, spray foam?, is a recipe for promoting future rust. Abrade and clean the metal thoroughly, paint with epoxy, seam seal any lapped or pinch welded joints, and top coat if desired. Keep clean and dry in the future.

Make sure the "weep hole" (drain hole) on each cab corner is not blocked.

I live in the Northwest and it will be a daily driver. Rains here a tad. I think the real issue is the rear windows will leak. I would like to see some data that says spray foam holds moisture. In my case it's sealed but I am not convinced it would cause moisture to be trapped.

The spray foam used by GM behind the rear quarter panel on my 70 Nova held moisture, until it eventually leaked out through the gaping rusted-out hole.

clean it the best you can then put a hevy coat of por 15 it will seal and hold off the future rust

the foam won't hold moisture within itself, but it will trap any condensation caused by the temperature difference between it and the metal because it's not a tight "barrier coat" on the metal like paint is ... it's also flammable, up here insurance folks really don't like foam insulation in RVs

Bill

We have done what leonard suggests on the two cabs we are working on now. At prime-time, we roughed-up the POR and sprayed on epoxy primer.

Thanks Leonard - I've never used por 15 as it seems to be a hassle to use. At least from what I've read about when doing a large project. This seems like a small enough deal that I will give it a try to see what the outcome is.

Thanks Tim. Coating with epoxy primer would have been my next question.

I had a 1951 truck bought for parts, that had the corners filled with cement..... Of course they were already rusted out in the bottoms. I guess it was a fast fix for a problem. LOL
Biggest thing is moisture and dirt that collect in the corners. Even the outside of the gas tank probably sweats with changes in the weather.

John

http://www.lizardskin.com/

I haven't tried this yet but it seems to be a big hit on the car shows on TV. Sound deadening, heat dissipation and noise control. I thought of spraying this in the cab corners, behind the gas tank, the floorboards, etc etc.

If I'm not mistaken the sound deadeners are basically a mixture of glass or ceramic spheres suspended ina heavy weight paint to increase density of the dried material and thus reduce vibration. If hollow spheres are used it would have an insulating quality as well.
So a good heavy weight paint (like say a can of titanium white traffic line paint available at your local FLBBS) and a gal of spheres might be the DIY alternative.
I liked it (the DIY alternative) in my case because if I want to take any off it comes off with reasonable ease. IMO to many guys think a repair has to mean forever and ignore the next poor fool who has to get past the 'repair' to fix whats under/behind it. (Which is a big reason I stay away from the POR products... )

Putting specific sound deadeners aside, my original thought was:

1 - sandblast
2 - epoxy primer
3 - coat with bedliner product (for sound as well as durability - the entire floorboard area and back of cab may have this as well - yes I would keep the weep-hole clean)

The POR 15 seemed harmless enough for such a small area.

So my question to CASO is - given the hidden-ish nature of this area, what is the downside of using POR 15 there? Is there a genuine issue with this stuff or is it generally not needed when I have already blasted the snot out of this area?

Thanks for the help.

If its bare blasted metal then why are you even thinking about POR?
POR is a Moisture Cured Urethane. MCU's are typicaly used for Bridge's.
MCU's are not a flexable as Epoxy Primers making cracking from repeated stress flex more likely.

MCU's are made to adhere to and cover up rust and keep it from spreading.
Epoxy Primers are designed to protect bare metal.

Use the right product for the job at hand....

Here's an alternative to the lizard skin. Basically micro spheres mixed in with the paint to give it real tiny air pockets for sound deadening and insulation. Real tiny.... Comes in 2 qt container


http://www.mcmaster.com/#micro-spheres/=pfpqkj

Robert, would you choose solid or hollow micro sphere's for the sound deadening or insulation values?
As I recall when I did my research on it I chose the hollow spheres for their insulating quality but picked the heaviest can of paint I could find in the clearance shelf at the Box.
Just curious what your thought are for recipes.

My guess would be the hollow spheres would be better in insulation and sound deadening. I think you can safely mix these in the primer that was planned, and topcoat, if needed. Based on the size of these, I don't think there will be an issue of the surface looking rough, so possible spheres mixed in the topcoat within the cab as well, for additional benefit.