If you can't reach the rust - what do you do?

P

PerryH

Hello.

I actually found this forum after performing a Google search for "POR15 sucks" as I was skeptical of the marketing. I think I found the right place to ask this. :)

I am restoring a (pretty solid so far) 1971 Pantera.

Presently I have the drain area under the cowl vents down to bare metal using a flexshaft dremel with flapdisk sanding wheels and wire brushes. I have cut my hands trying to get back in there as far as possible, but there are still places I cannot get to that have surface rust on them. I have a sandblaster, but that won't get in there far enough to get it all either. (Also, this is a monocoque chassis. The fenders do not come off. I would be blasting blindly on the underside of the front fenders so I could warp them from underneath if not careful with the abrasive selection and/or blast angle.)

This is just the cowl area for now, but later I'll be taking the undercoat off and there are frame rails where I will have a similar problem.

I have read enough here to see that the agreed upon answer is to blast everything down to bare metal, then coat with epoxy primer.

Fair enough, but what do you do in places where a sandblaster will not reach? Just shoot it with epoxy and coat with cavity wax? Or phosphoric acid to convert the surface rust first?

In the case of the cowl I do have the luxury of this being a water passage such that if I needed to rinse of Ospho or a similar product, the water would go out through the factory drain tubes (which are metal and I will clean the insides of using a cylindrical wire brush). Painting those will be a paint soaked sponge on a string after pouring a bit of paint down the tubes first.
 
Waiting to see if someone else says jig it up, cut it off, blast it and weld it back together if there is that much concern.
 
Assume cutting bodywork is not on the table.

The surface rust is not particularly concerning - definitely not enough to cut into a straight Pantera. If I had any reason to think it was structural, cutting would happen, but I do not. It is just surface rust that I want to prevent (or maximally retard) from turning into something worse.
 
I have, but I got some less than satisfying responses.

One guy said he plans to use LizardSkin insulation spray. Another guy recommended Rustoleum and Flex Seal.

Another more workable suggested solution was to paint as best I could and then cover it with chassis wax (which I presume is the same as cavity wax?)
 
Here are a couple. First what it looks like in most of it. Then in the second you can see some of the rust I can't reach. This is under the driver's side fender. The other side is similar.

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20190601_164715.jpg
20190601_164715.jpg
 
Maybe Ospho applied with a shutz gun with a 360 degree wand attached. Let it sit overnight, then reapply Ospho and rinse thoroughly with distilled water in shutz gun while Ospho still wet. Dry thoroughly with air hose, leaf blower, heat gun, whatever you have, and apply epoxy with shutz gun with wand in cavities, regular or touch up gun for reachable areas. Not sure what the Ospho will do to the gun but should be fine
 
must .....hijack. more pics!! im a fan of any car with a cleveland but the pantera....call me nuts but id take one over a ferrari or lambo any day.
are ya using SPI products? if not, i strongly encourage you looking into using them.
 
What's that size opening?

I used a 1 inch pc pipe and duck taped it to a wet vac hose and was able to get the hose into places I could not previously and suck out the crap. I would consider this same set up in the same spots with sandblasting up closer. I have yet tried it, it might fail, but I'm thinking.
 
Its between the panels, so nothing you are going to do mechanically will get it all. If you want to trust Ospho, maybe you plug the drain hole and fill the cavity with it, let is sit for a few hours,, catch it in a bucket and then continue to flush the area with ospho til it gets rinsed away.

Other than that, Eastwood has a new product they call Platinum out. Dont know who's it used to be or what it is copied from, but its just a one part product. But you wont end up with the bare metal most epoxies want. I picked up a can and sprayed it and it dried really hard overnight when it was proably 50 in the shop. Surprisingly hard. (from Goon) Gay porn hard. More of hard and slick than just hard.

But to me, that just questions how anything on top of it is going to stick, and its platinum, or silver so you would probably not look right unless it was top coated.
 
To me this is exactly what Ospho is for. Areas that you cannot get into. I would try fixing a sponge or cloth to a wire coat hanger and soak that rusted area real good. Might take a couple of coats before it converts all the rust (turns black). Then apply one more coat and while still wet use the sponge technique with soapy water to wash it as best you can. Rinse with a hose and immediate blow dry with compressed air.

You will probably end up applying the epoxy primer and (if you chose to) paint the same way in those areas.
 
I have, but I got some less than satisfying responses.

One guy said he plans to use LizardSkin insulation spray. Another guy recommended Rustoleum and Flex Seal.

Another more workable suggested solution was to paint as best I could and then cover it with chassis wax (which I presume is the same as cavity wax?)

Please don't do any of those, that's a nice car.
 
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