Dealing with Rust

[IDC10]

How do I best deal with the light rust inside the cowl of my '68.
I really do not want to drill the spotwelds and pull it all apart.



Do I need to cut this metal out at the bottom of the windshield and weld in a new piece? Or should I take some rust neutralizer (like Loctite or phosphoric acid) to it?



I want to epoxy prime the firewall, re seam seal with a 2K sealer, then paint it in a single stage GM light green to roughly match the rest of the truck. I'll also take some epoxy primer around the windshield frame, seam seal and paint it in the GM white.



Strategy is to rock the faded paint and run a patina truck for awhile. I've rebuilt the entire chassis...just need a cab to go with it. I'm too lazy to do the rest of the bodywork for now, but wish to preserve the truck from further rust.

[cdub2010]

I had the inner cowl off my truck in a few hours, it was a good move since I had holes thru mine. If its solid, I would spray some metal etch phosphoric acid type solution to clean up the rust. If It thats now bad it is after 50 years, you might not have much to worry about going forward. Just dont leave it parked out in the back 40 for the next 50 years.

[lupo]

Most effective method for dealing with rust is to remove the paint and then treat it with a phosphoric acid solution. There are phosphoric acid rust removers with zinc that are effective especially in welded seams . It dissolves the rust and leaves his Zinc film. Panels treated like this they can stay indoors for a year without re rusting. Two coats of a aluminum pigmented permanent rust sealer Do not use black follow it up with any kind of primer you want over that and then your color. By utilizing a phosphoric acid solution and top coating with an airtight seal you have done everything humanely possible to prevent rust.

[IDC10]

Originally Posted by lupo

Most effective method for dealing with rust is to remove the paint and then treat it with a phosphoric acid solution. There are phosphoric acid rust removers with zinc that are effective especially in welded seams . It dissolves the rust and leaves his Zinc film. Panels treated like this they can stay indoors for a year without re rusting. Two coats of a aluminum pigmented permanent rust sealer Do not use black follow it up with any kind of primer you want over that and then your color. By utilizing a phosphoric acid solution and top coating with an airtight seal you have done everything humanely possible to prevent rust.

I have some SEM RUST SEAL. It brushes on white and turns into a black coating. I think I am going to just clean as best as I can then coat with rust seal and epoxy prime and paint.

I could cut the cowl apart for access and weld it back together, but I it's just surface rust and not rusted through. Hate to risk more harm than good.

[Foot Stomper]

Scuff it, wipe clean with a wax and grease remover then apply a good quality epoxy primer as per manufacturers directions and call it perfect. No other work required.

[franken]

I'm a proponent of (diluted) generic phosphoric acid available at any home store as a concrete etcher/cleaner.

Regarding post 3 and a zinc coating, no it doesn't. No magic zinc material appears with phosphoric acid.
Unless you immerse (or keep continuously wet) a piece of steel in P-acid (or whatever rust remover) for some time, you're just removing the top layer of rust. Sanding will show more rust.

I'm just trying to debunk some myths.

It is possible to get a pump and keep a surface wet the the surface with the acid for a time to remove rust, just don't let the acid get on concrete since it will dissolve concrete.

Most rust removers are phosphoric acid based but the brand names aren't cheap. You can pay for the name on the label or the product in the bottle.

[lupo]

The metal prep that I use has four ingredients and one of them is zinc. As for epoxy primer great for a body shop paint job . But that's what failed the first time When you do preservation work like I have for the last 40 years I use the most powerful industrial primers available. There are restoration shops that Prime the entire vehicle inside and out with the aluminum pigmented moisture cure and have for the last 20 years.

[HO455]

This is not a product I have used but the process looks like it may be good for what you want to do.

https://youtu.be/r1HfA6MIHuU

Then use a sprayer with a flexible wand to coat the voids. I have used a Chemicar sprayer to spray POR15 into voids with good results in the past.


http://www.chemicar.com/tools/underc...tproofing-gun/

[MP&C]

Originally Posted by lupo

As for epoxy primer great for a body shop paint job . But that's what failed the first time

Chevrolet did not use epoxy primer in 1968, so that is NOT what failed the first time. Perhaps you meant to say lacquer primer

[lupo]

Thank you for bringing that to my attention. Was that primer electrostatically applied at that time ?. I remember getting yelled at for grinding It Off. My mentor always said you'll never get her primer that good. I built the salt fog chamber from the internet I think I'll use three coats zinc phosphate epoxy versus the aluminum pigmented moisture cure to see how far they go . Should be interesting