rust proofing hat channels

aforests · Post by **aforests** » Wed Jan 27, 2016 2:51 pm

I am almost to the point of priming my m38 body, but am pondering what to use in the void support channels, especially the rear inside fender ones that had rusted portions of the body out. Although I patch welded all those areas, the channels on the underside of the body need to be sealed so when moisture shows up in the future it doesn't start to rot away again.

It's going to be hard to spray anything in those channels to get good coverage. Looking for ideas on what others have done.

4x4M38 · Post by **4x4M38** » Wed Jan 27, 2016 3:05 pm

Hi Aaron
Tons of info on hat channels by searching here. Be sure the hats have supports where the bolts go through if you don't put the wood back.

The consensus I've seen is if you are welding the hat channels back on spray them with weld through primer where you won't be able to access later. . The welds will go through and most of the primer will stay in place.

If you already have rust you'll need to treat with POR or something, then prime. Assuming you've already welded them on.

aforests · Post by **aforests** » Wed Jan 27, 2016 3:24 pm

Thanks Brian.

Most of my channels don't have wood anymore, so I was hoping there was a product out there that could be sprayed into them to prevent rust. Would need a long nozzle or tube to get the product in though...

aforests · Post by **aforests** » Wed Jan 27, 2016 3:29 pm

Found what I was looking for. Waxoyl or cavity wax. Had a guy one time tell me about it. Anyone used it before?

ruger45 · Post by **ruger45** » Wed Jan 27, 2016 8:50 pm

That's what my body guy just used on my windshield frame. I don't know if it works but he says it seals up all the spots the he burned the primer of when welding it back together.

OKCM38CDN · Post by **OKCM38CDN** » Wed Jan 27, 2016 9:39 pm

I was wondering what to use myself

I was thinking of spray foam the expanding type that comes in a can. Spray it into the channels then clean the excess up and go from there... it would fill the voids and be waterproof. You want to get some that sticks to the metal, some does not...

Post by **wesk** » Wed Jan 27, 2016 11:35 pm

If the channels are left with drain openings and no wood installed they will dry out after each wetting on their own. The reason most projects start with rusted hat channels is because the wood used to reinforce them held the moisture and accelerated the rusting process. But even then they still survived 50 + years. So if you weld proof primer their insides, leave drain openings, reinforce the bolt through holes with welded in bushings and DO NOT PUT wood in them they will last longer than 50+ years the next time.

If you still feel that must coat them inside with something then use what has been used to seal and rust proof fabric covered aircraft steel tubing since the 1920's. Linseed oil. You can thin it, spray it and it will dry and seal. Or you can rotate the tube while pouring it in each channel filling the channel and then letting what wants to drain out drain out.

DanS · Post by **DanS** » Thu Jan 28, 2016 7:09 am

The foam is a bad idea. It never completely bonds with the mating surfaces and will leave voids that moisture will inevitably find.

Dan

Xamon · Post by **Xamon** » Thu Jan 28, 2016 8:18 am

I have seen many places where people filled voids with expanding foam and they rot very fast and far worse than if they had just left it alone.

OKCM38CDN · Post by **OKCM38CDN** » Thu Jan 28, 2016 6:01 pm

Well so much for that idea

Have not done it so I am good to go...

Jeff_Lee · Post by **Jeff_Lee** » Thu Jan 28, 2016 7:08 pm

I am a big fan of using POR-15 in blind areas, like hat channels and frames...
POR-15 is readily available, easy to use, and really stops rust in it's tracks.

Wax-Oyl, and the like, are popular in England where it is damp. They use it on non-treated or undercoated frame and body cavities. I have found it to be messy, and in hot climates tends to bleed everywhere on a hot day. At best, it's protection lasts a couple of years so you need to re-apply regularly.

I used POR-15 on the new tub floor and on the complete hat channel, before re-welding to the tub. After welding, I used small pieces of upholstery foam rubber on the end of a coat hanger to fish up the hat channels. I saturated the foam in POR-15, and drew them through all the blind channels where possible. Did the same on the boxed portions of my sandblasted frame, too. You can thin the POR-15 a bit with their reducer, and it applies well on the foam... yes, it is messy - but worth it for the long term protection.

The POR-15 is hard as a rock after a couple of years and there is no signs of rust.

Claudio · Post by **Claudio** » Tue Jun 14, 2016 9:16 am

Hello guys, you probably have already found the solution for protecting the inner hat channels and other blind parts of the body, like the windshiled frame and fender reinforcements, but this is my hint: the product name is Tectyl and easily found in Ameirca as well. I've been using this in my MVs. By the way, when patching hat channels, all remaining wood must be removed.