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How to treat bare metal in tough spaces

Cudachuck

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I have my cuda blasted and was wondering what is the best way to treat places like between the roofskin and roof structures? The car is on a rotisserie if that might make the treatment process easier.Thanks
 

LLLFarm

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Ospho all day. Spray it on, dry for about 24 hours, wipe off the residue and paint. Concrete and metal prep from HD and Lowes is about the same thing for less than half the $$$.
 

Rich Followell

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You may have to remove more metal a get all the corrosion. there are many products that may help but none can match pure labor and quality commercial grade products

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gzig5

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Ospho is thin and will run in between the panels. Forms a pretty hard black surface that after a quick wipe down takes primer well. I do recommend priming and painting anywhere you can get to after using it. I've been using it on my son's Tacoma frame and if not painted, the part may continue to rust a few weeks after treatment. I've heard good things about Corroseal for frame rust but it is a gel and still should be painted afterwards. The easiest way is to dip the car to clean it and then dip again in primer but that is not a cheap effort.

@Rich Followell
Props on your roof structure effort. That had to take some patience. Mine looks about like that but it's still attached to the rest of the car. Any chance I could get some pics and measurements on the position of the center cross bar? Mine was removed for the installation of a flip up sun roof back in the day. I found a replacement and would like to make sure it goes back where it should.
 

Adam

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Yes, paint after the rust treatment is thoroughly dry. Also, for light rust you can use etching primer, however some top coat paints will react poorly.
 

Rich Followell

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Ospho is thin and will run in between the panels. Forms a pretty hard black surface that after a quick wipe down takes primer well. I do recommend priming and painting anywhere you can get to after using it. I've been using it on my son's Tacoma frame and if not painted, the part may continue to rust a few weeks after treatment. I've heard good things about Corroseal for frame rust but it is a gel and still should be painted afterwards. The easiest way is to dip the car to clean it and then dip again in primer but that is not a cheap effort.

@Rich Followell
Props on your roof structure effort. That had to take some patience. Mine looks about like that but it's still attached to the rest of the car. Any chance I could get some pics and measurements on the position of the center cross bar? Mine was removed for the installation of a flip up sun roof back in the day. I found a replacement and would like to make sure it goes back where it should.
Well I looked at it before taking measurements and realize there is no need to. On the inside of the roof pillars roughly near center you will find a flat spot with three raised bumps this was for the factory workers to locate the part perfectly every time. One on the bottom and one on each side. you should also be able to find marks from the removal of the original part.
 

Adam

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How hard was it to get the whole roof skin off and was it still usable or did you replace?
Why would you remove and reuse the roof skin? I did a roof skin on my 71 Challenger, it had many dents and was very rusty underneath. It was not too bad of a job because you get to stand up next to the car and have great access.

You need an American made spot weld cutter bit… don’t bother with the Chinese bits, trust me; get the ones that look like a flat end drill bit, not the ones with little saw teeth.

You need to take out the windshield and back windows, and all the side drip rail trim and window channel stuff. Use an abrasive disc to remove the petrified seam sealer from the rain gutter and expose the spot welds. Use an abrasive disc, or other means to expose the roof to 1/4 panel seam. (Although you could cut and weld elsewhere). Use the spot weld cutter bits to drill halfway through the spot welds along the rain gutter and along the top of the window openings. You do not want to drill all the way through. Cut the 1/4s from the rear window opening to the rain gutter, or remove the factory welds, and the roof panel should be removable. I did mine in an afternoon.

While my roof structure was exposed I cleaned, used Ospho, and painted it.

On my AMD replacement roof panel I punched holes every couple of inches along the front and rear window openings for plug welds; along the rain gutters I used body panel adhesive after prepping the surfaces.

Do not forget to install new window trim clips! And new seam sealer in the rain gutters.

Link to my album; pics 125 to 135: Challenger
 
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Rich Followell

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The roof skin was removed, repaired, and will be reused. it was very difficult there are about 125 spot welds that penetrate as many as three layers. in our case when the car was built the tips on the factory spot welder were already quiet worn and produced peanut shaped welds the resulting in the about three times the normal time it should have taken. I recommend reuse of the original roof when ever possible at least you know it fits you simply line it up with the old holes clamp it weld it and or glue it!
 
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