The Stovebolt Site Forums The Shop Area Paint and Body Shop Inner cowl and kick panels

I am redoing the cab on a 1954 3600. The cab is excellent with no rust except the inner cowl and kick panel. I also have a 1954 4400 excellent cab except for the cowl and inner panel. Is there any way to prevent water from getting in to the cowl area after I make my sheet metal repairs? This seems to be a common problem with a lot of AD trucks.

Short answer is no, but it took about 30-40 years for the first panel to rust out, so new panels should last even longer under todays conditions. Your always going to get water through the side louver, and splash up from the tires. The biggest problem stems from the cowl filling up with dirt/dust and holding moisture. Once the panels have been replaced you could seal the entire area with undercoating, and plug the louvers to keep water out. Note if you want fresh air for heater, you can't plug louvers?

Roughie,

After you repair the panels and seal the seams at the floor, how do you think that water would get in?

- top cowl vent seal?
- poorly fitting top cowl vent hose?
- windshield leak?
- door seal leak?
- door-windows seals leak?
- ??

I think the rusted out floor corners are as much or more the blame to rusted metal on the outer side (stone chips and not so good original primer/paint leaving metal exposed to exterior water).

I wonder if water enters at the firewall where the top of the fender attaches. There is a small plate with rubber seals stapled to it. On most of the unrestored trucks I see the rubber seals are missing.

I think a good coat of epoxy primer and an improved drain hole would help more.
The cowls collect dust and dirt and pieces of limbs and that shifty stuff settles down then backs up in all those bottom areas holding moisture and more dirt. If its oak or some other acidic plant as it breaks down you got all the makings your gonna need.
It's not about the water getting in... Can it get back out?

When using an epoxy primer or rust inhibitor on a sealed area where welding is needed to seal up the area should I be concerned about the hidden areas that the weld burns off?

I'd try and get the welding finished then prep and paint. There are omni directional spray wands that can be used to get in hard to reach spots.
Self healing seam sealers would be a good option. Maybe prepaint the panel inside with the epoxy leaving a couple inches clear where you'll be welding then finish with the seam sealer.

Then there is weld-through primer. Its made for this purpose. Not sure if its what you need, but look into it anyway.

Rust never sleeps, but whatever method we try to keep it under control is infinitely better than what the factory did when originally built. I would recommend doing what is practical and be relieved that your work will last much longer than the original.

Thanks for the suggestions I agree that what ever we do as a repair will better than factory.

I've often wondered if something like this would work. Looks like a couple small purposefully placed holes and coat the inside.

internal frame coat