Treating Underside Surfaces

[pschlosser]

How should I go about soaking the rusty underside of my Barracuda roof with a liquid rust treatment product?

In a thread by @don selleck he is showing us his AAR restoration project where he turned me on to a rust treatment product called Eastwood After Blast. I've used a similar product many times. I get the best results soaking the rusty item(s) in a tub of the product until the rust is gone. Now, you can paint it or spray it on areas that are too large or impractical to soak, but it takes much longer, and requires repeated application to get good results.

It's impractical for me to rotisserie this car at this time. But I would sure like to treat the rust that's up there. I can use a paint brush and/or spray bottle, but I have a couple of concerns:

1. In my experience, I will have to reapply the product many times, before the job is through. By many, we may be talking 30 applications or more.
2. If I apply too much product, it may run down the metal, and behind the outer support structures at the edge of the roof, and attack the factory primer, and also pose a challenge to later rinse and neutralize.

There's gotta be an easier way. One thought I have is to use paper towels, soaked in solution, and then pressed flat onto the roof where I presume it will stick for a while. I may be able to use a sprayer to remoisten the towels as the job progresses. But it may still run and ooze down behind the edge supports.

So what do you guys think? Y'all got any idears?

 

[don selleck]

you need to sand and remove as much as possible, afterblast is a metal etching for adhesion promotion and leave a zinc coating. you got alot of sanding to do first. then use a spray bottle to apply it, a little goes a long way, and remember its acid is will f---k you and other things up. eastwood sells it. there site has directions and reviews. then I would get a rattle can of primer.

 

[gran coupe john]

You probably won't like this, but I used this on the underside of roof. Used this on the 61 f100 frame. Has held up well.

 

[pschlosser]

You probably won't like this, but I used this on the underside of roof. Used this on the 61 f100 frame. Has held up well.

I hear ya. If it bothers me so much, why not just hide it? I've looked at those Rust Reformer products and I'm just not so sure I want to go there. The rust on the roof in the picture is not at all severe. Over the last 5 years, I've been using rust removal products on many things around the shop. So I think I know which product I want to use and how good the results might be.

I recently bought a headliner, and it got me thinking, "I'd sure like to get that rust treated before throwing a headliner back up there." But as I said in the OP, I'm not sure how to pull it off. At least, I have in mind to soak it, for several hours or days. Until I let go of that, I'm trying to work it out. Flipping the car over would sure do the trick, though!

 

[gran coupe john]

Better drain all the fluids lol. Sure you will figure it out.

 

[don selleck]

I would just scrap it back and use some etching primer, if you wanted you could spray bottle some of the after blast first, lightly and put some rags etc. on the floor to catch it. let it dry good maybe warm it up slightly with a heat gun to dry it thoroughly. but i would physically remove as much as possible prior to any coating.

 

[Xcudame]

Zooming in on your photo, it really doesn't look too bad. I say sand it well and spray the Rust Reformer on it. That acid from Eastwood would be pretty unsafe applying overhead I would think.

 

[don selleck]

I agree

 

[cuda joe]

save yourself the headaches use rust converter

 

[Challenger RTA]

If it bothers me so much, why not just hide it?

If your not satisfied with the results. It will still bug you.
I would pull the seats, cover the carpet with a tarp. Cover Dash rear shelf and back panels. the same. You could leave the doors open and drape something over them.
Then I would go at it with a palm sander with 100 or 80 grit. See what works,I don't see it taking a sheet or more.
I always like a metal prep afterwards. I SEM Rust Mort. Use a squeeze sprayer. Roll,brush or spay bomb primer and pant.
If you it's bugging you know it will be bugging you later if not done to you satisfaction.
Been there done that twice and it done twice as nice. Yeah no one is going to know it but you. Sometimes I over think tings too instead of getting it done.

 

[don selleck]

sounds like a good plan to me, removing the majority and stopping the rust. then on to the next area that needs addressing, always several of those in these old cars.

 

[Challenger RTA]

Had to find it in the basement, brought it in from the garage. This is what I use and like the results. Sem about $40 but wort it. About $20 for the Evapo rust.
Oh yeah the SEM burns when you get it in a cut.

 

[pschlosser]

I've got several good recommendations, here.

all good stuff, guys. thank you.

 

[terrywalker]

I used what has been recommended in previous posts on the roof of a Challenger I'm doing. I used 220 grit paper to remove the rust. I then wiped all dust off with a tac clothe. Using a brush, I applied SEM Rust Mort and let it dry. I then used a bucket of clean water and with a wet rag wiped all surfaces covered with RustMort. I repeated the water wipe down a couple of times and let dry. This leaves a gray colored surface that can be painted. I sprayed a red Professional Rustoleum Enamel that is close to the color I'm painting the car. It turned out great.
Terry W.

 

[don selleck]

was just looking at the eastwood site, they make a rust dissolving gel, might be your answer? $18 a quart on sale now till tomorrow

 

[gzig5]

I used what has been recommended in previous posts on the roof of a Challenger I'm doing. I used 220 grit paper to remove the rust. I then wiped all dust off with a tac clothe. Using a brush, I applied SEM Rust Mort and let it dry. I then used a bucket of clean water and with a wet rag wiped all surfaces covered with RustMort. I repeated the water wipe down a couple of times and let dry. This leaves a gray colored surface that can be painted. I sprayed a red Professional Rustoleum Enamel that is close to the color I'm painting the car. It turned out great.
Terry W.

View attachment 133647

I assume the water wipe down is to remove the Rust Mort that hasn't reacted so it doesn't affect the paint?
I've been using Ospho on my car and while I haven't applied much paint/primer yet, that is a step I've been contemplating. I was also going to use the Eastwood internal frame coating with the tube to apply it down into the A-pillars and enclosed roof support structure. Roof is off so I can get to most of the surfaces. Wish they would have dipped the cars all the way under in the primer tank 55 years ago. Lot of that inner structure would weather time better with a coat of something rather than raw steel.

 

[Xcudame]

I know rust is a serious issue with our cars, but we forget back then, they didn't want to car to last 50+ years! They wanted us to buy a new vehicle every seven years or so. And there are so great tips here how to deal with rust. I'm actually amazed at how many Mopars are still around. Percentage wise, I'm guessing we're doing better than GM and Ford.

My opinion, feel free to disagree, the main thing is to seal off the rust. Without oxygen, there is no rust. Anything you treat the metal with and coat it with (paint) is going to allow these cars to exist longer than us, our children and grandchildren.

 

[Juan Veldez]

I used Por15 on everything that was rusty and would be covered/unseen. Probably similar to the Rust-oleum product as it creates a bullet proof finish as it binds with the rust.