My take on Cab tub rot

[Wayne64]

When I purchased my M37B1 in around 2008 it already had extensive rot in most of the sheet metal. Part of the problem is the salt used on the roads and what probably made it worse was the last owner, a rich know nothing, who used it on the beach at his house. Which happened to be on the Great South Bay SALT WATER! He also had a canvas top that was both ripped and leaked like a sieve. Bottom line is the truck was always hit with water from below (salt) and rain from above. I'm going to post two photos of my cab, then two of my replacement tub with arrows where I think drain holes should be drilled. I would like opinions please.

Front tub rot


Rear tub rot


Front drain locations


Rear drain locations

[Cal_Gary]

I would think if you cut out the rot, prep and use a rust inhibitor, that drain holes wouldn't be needed (but I don't know how you intend to use your M, Wayne). I will say this: my original cab was rotted like yours times 50, therefore not worth saving, so I swapped in another cab (thanks Kurt Hirte!).
Gary

[Wayne64]

What I didn't show was how my drivers side A pillar is no longer tied into the bottom of the tub. The rot is so bad that you have to slam the drivers door to force the sagging tub back apart. No matter how I prep or don't prep the replacement tub it will out last me, that is not why I was thinking of the drain holes. If this is a typical problem why not try to improve on the design? Eventually there will be a shortage of decent cabs for the restorers of the future. My truck never sees a garage and I do work it. My M37 will not see a show either and I gave up, long ago, being a purist on my builds.

[Cal_Gary]

I hear you Wayne,
Mine won't be a 100 point winner either but I modify those things that don't readily show as "field mods".
Gary

[refit1701]

I thought of putting drains there too, when my cab is finished. All four of the bottom plates are gone on my cab.

I will probably drill a small hole and then flare it down towards the ground. We used to do this on old Mustangs.

[Wayne64]

I thought of putting drains there too, when my cab is finished. All four of the bottom plates are gone on my cab.

I will probably drill a small hole and then flare it down towards the ground. We used to do this on old Mustangs.

My thoughts as well on the flared hole. Now that you brought up the mustangs; When I did a repair, on my sons 65, in the cowl area where it leaked into the cabin I coated the whole area with asphaltum after welding in the patches. Never leaked again and that may be an extra step in the cowl vent drain area of the M37.

[refit1701]

There's not much room in that cowl vent channel for too much asphalt sealer. I think that a good coating of epoxy sealer/primer, followed by paint will do ok.

You know they sell the entire cowl vent area for mustangs now? When I started out it was custom work. I wish someone would make the cowl channel for our trucks.

[Wayne64]

You know they sell the entire cowl vent area for mustangs now? When I started out it was custom work. I wish someone would make the cowl channel for our trucks.[/quote]

Being a major stainless steel fan, if the piece gets made L304 or better. I know if I had to make one it would be out of S.S. or even sectioned copper tube silver brazed. But thats just me, quite crazy

[k8icu]

You call that rust! Hah! I laugh at your rust...

A cab can be fixed even in the worse of conditions

Before




After



Still working on it, but it can be done.
I agree with the holes for the drainage. I'm thinking of shooting rustproofing up there after I get it done. I plan on rustproofing the bottom of the cab also.

[poor rich]

On the subject of rust proofing, I haven't paid much attention to it but the only rust proofing I've seen is sprayed on tar.
What do you guys think of spray on bed liner used as under coating? It would be tuff as hell.
Rich

[Wayne64]

On the subject of rust proofing, I haven't paid much attention to it but the only rust proofing I've seen is sprayed on tar.
What do you guys think of spray on bed liner used as under coating? It would be tuff as hell.
Rich

I would like to hear everyones opinion on this also. I brought my replacement tub home today and peeled some undercoat off the underside. What I found was perfect original paint. Unlike when I was much younger if a car had been undercoated (tar and the selling point for the dealers was sound deadening) there was more rot due to the undercoating holding moisture above it. My F150 has Line-X on the bed and that sure is durable.