Opinions on inner cowl rust repir

[rechinca]

I have a small patch of rust in the overlap seem where the inner cowl and cab metals meet on the passenger side. I have already cut away some of it to start planning the repair. I have a bad feeling I will need to pull the inner cowl and replace that piece as a whole. Plus I think it will allow access to this area as a whole to better attack the rust under it. I also have a rust area on the LH side where the reinforcement is behind the inner cowl. Bought a piece to repair it from an original cab, but I am starting to think time and proper repair/rust abatement in the fresh air vent area will be the best plan. I have read a lot of the threads on cowl repair, just wanted to see if anyone else has done it recently and documented it.

[rechinca]

Also, in the first pic, it looks like the metal from the piece under the inner cowl never went all the way to the firewall. I pulled a huge pile of that wonderful factory seam sealer out from that same spot. I can’t tell if the hole is formed to the sealer. Or was it a straight line of metal that left a huge gap they hoped the sealer would just plug up. I reposted the pic here with a circle around the point in question.

[toolboxchev]

I had to do a search for this one, it goes pretty deep. There is a lot of work involved with some cabs. Ask me how I know, I have been battling rust for over 12 years now.

Someday I will get into mine, or find a solid cab. Some prefer the cost effective way of a good solid cab, yet there is quite a bit of research in finding one.

Check out this thread in its entirety: http://67-72chevytrucks.com/vboard/s...d.php?t=705214

[rechinca]

Toolbox, I have actually reference and read through tour thread MULTIPLE TIME for great documentation and places to look carefully into mine. I know I have more rust than I would like, but I think it will help me appreciate it more when I’m done. I have similar rust issues in places like yours, just not as bad. Although I feel like it will be death by 1000 needles fixing the small spots. That I have no where but but slopes driveway to do mine so it will get done bit by bit trying to keep it a driver as much as possible while I work on it. I am thinking I will pull the whole inner cowl to fix the issues under it and the overlapped metal. If I can get that done before the rainy season (hopefully by the end of October) then I can drive it over the winter and stockpile metal to do the kick panels, rockers and floors starting in the spring. The benefit of the arid Central Valley climate in the spring-fall.

[BigBird05]

I have just bought a front of dash, cowl, dash section out of a 68 C-10. Spent about five hours drilling out all of the spot welds to repair my truck that has the same rust problems. I can send you some pictures of all the separate parts if that would help.

[rechinca]

Originally Posted by BigBird05

I have just bought a front of dash, cowl, dash section out of a 68 C-10. Spent about five hours drilling out all of the spot welds to repair my truck that has the same rust problems. I can send you some pictures of all the separate parts if that would help.

That would be awesome! How many drill bits did you go through, or did you go the spot-weld cutter route?

[BigBird05]

When I try to upload the pictures I get invalid file, What does this mean and how do I get around it?

[Jason Banks]

I have been drilling some spot welds lately and have good luck first drilling a 1/8 hole right in the middle and then using the harbor freight spot weld cutter to finish it off.

[Jason Banks]

I have similar rust on a 68 that I'm working on. I'm still undecided, but I'll probably end up drilling out the spot welds on the outer cowl and taking it off to work on that area. I figured I would just cut out all of the overlap and butt weld the pieces together.

I'm not sure exactly where the hole you circled is, but it would not surprise me if they didn't just use that crappy foamy seam sealer on it.

[AussieinNC]

Originally Posted by BigBird05

When I try to upload the pictures I get invalid file, What does this mean and how do I get around it?

BigBird05...The screen shot attached will show you the accepted file types for the forum...

Accepted image formats are listed....most pics taken with say an iPhone are in .jpg format....which is acceptable....

If you have a Windows computer, use Paint program to open the pic you have, then save it using Save As option as a jpeg...

Hope this helps

[rechinca]

Originally Posted by Jason Banks

I have similar rust on a 68 that I'm working on. I'm still undecided, but I'll probably end up drilling out the spot welds on the outer cowl and taking it off to work on that area. I figured I would just cut out all of the overlap and butt weld the pieces together.

I'm not sure exactly where the hole you circled is, but it would not surprise me if they didn't just use that crappy foamy seam sealer on it.

It is looking down into the cowl on the passenger side right where the cab metal overlaps under the dash and the inner cowl come together. And yes it was where that crapping foam seam sealer was layered in amongst the seam. Not surprised that it rusted there, that gray foam is about as well thought out as using expanding foam. It just shrinks and collects water. Nearly 50 year old technology that by today’s standard is a “what the hell were they thinking” moment!

[rechinca]

So after working 96 hours from last Sunday through tonight, tomorrow I get a couple of hours to start the process of replacing the inner cowl. After getting a look down inside the fresh air vents, I decided that I want to treat that area so the surface rust doesn’t start becoming an issue later on. Plus the fact I would have to cut a section of the inner cowl out to replace some metal in that gutter area where the sections overlap. The same in the LH side where it rusted out at the fender mount/brace. I ordered up a Key Parts brand inner cowl from Jegs. I had a coupon and it shipped free via FedEx (boy seems they ate a lot of shipping on that box).

The plan is to remove the entire inner cowl, patch the underlying metal, then hit the whole area with Eastwood’s Platinum Encapsulator and paint it black. Then I will paint it with a gloss black and install the new inner cowl panel. I have 4 days off in a couple of weeks where I hope to have most/all of the work completed. Due to a long term Trans Am project hogging Up my garage space, I have to do all of this outside on the driveway...loads of fun!

[rechinca]

Got her opened up this week. Spent about half the day wrestling with spot welds. Used a couple of different tools: Blair Spot Weld cutter with pilot bit and a Dent Fix bit with their extender. Both worked well but man was it a challenge. Have a couple of places to fix where I over-penetrated, but all in all she is done. I am glad I decided to replace that whole inner cowl as I found some holes starting on the passenger side by the fresh air vents (going through to the outside) and one up under the RH fender mounts. Plus I now have much easier access to welding in the patch needed on the RH side instead of having to weld a patch in from under the dash.

Next question, what seam sealer to use at the top of the inner cowl and in the rain gutter at the base along the firewall? Any suggestions?

[rechinca]

A shot of the bare airbox channel.