OK; Rust-proofing/Undercoating?

Undercoating-choices or skip it?

  • Westley's or similar

    Votes: 0 0.0%

  • Rust-Oleum Rubberized Undercoating or similar

    Votes: 24 32.4%

  • Permatex undercoating

    Votes: 3 4.1%

  • Spray-on bedliner

    Votes: 22 29.7%

  • Other (please be specific!)

    Votes: 5 6.8%

  • No undercoating at all-paint only

    Votes: 20 27.0%
  • Total voters
    74
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Captainkirk

Captainkirk

Old School Mopar Warrior
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Those of you who have been following my resto thread know what I've been up to....wire wheeled all the rust, applied Rust-Oleum 'Rust Reformer' and am in the process of applying Rust-Oleum oil-based enamel now. I was planning on applying spray-on undercoating over the enamel after it dries. So; several questions..
1) Which is the best bang for the buck? I've used Westley's before, it's OK and relatively cheap but stays tacky a while.
2) Rust-Oleum rubberized undercoating seems like a natural choice as well
3) Any other reasonably priced product out there? Cost is definitely a factor and would prefer to keep it at/under 10 bucks a can
4) I've read several threads warning NOT to use undercoating as rust can develop through pinholes, voids, etc and work unseen under the coating. Sounds kinda scary...
Most important is the factor that this car will not see snow/salt/rain again if I can possibly help it but one never knows. I would appreciate any comments and user feedback on products used and your experiences. For the record, I'm doing underside and trunk internals
 
If you are never going to drive it in the snow again why undercoat it? Paint will hold up just fine.If you undercoat it I would try the Rust Oleum brand.
 
I don't have an answer for you or even an opinion. But I will need to make the same decision soon. My goal is original factory appearance. What's your goal? Rust protection, sound deadening, appearance? Maybe you could rank order those and get better advice.
 
68383GTS said:
If you are never going to drive it in the snow again why undercoat it? Paint will hold up just fine.If you undercoat it I would try the Rust Oleum brand.
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Captainkirk said:
Paranoia....
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X2 and X4

Traditional (tar based?) undercoat adds considerable weight, and can come separated, leaving cracks and voids that gather dirt and moisture Mine is doing that is some places, and right at the moment I'm tearing the car down for paint. I'll hit the bottom with a pressure washer to knock some more of it off

Hell I barely drive mine in the rain, much less snow.
 
I would leave it Paint, as the Upper Midwest dampness will creep in any little crack, and creviss.

barracudadave67
 
This came up on another thread, might be of interest at this stage. It's about the most rust prone area of these cars. The OP mentioned how a fresh paint job can fail in the area where the trunk extension meets the rear quarter. It's very difficult to see if you have corrosion about to break through from the inside out in this area.

I think its the worst water trap on these cars. What I plan to do is slice it just above the lower horizontal attachment, bend it up so it can be inspected and sandblasted. Replace metal if necessary. Then weld shut again but leaving some sizeable drain holes. POR 15 with a swab. Polyurethane caulk beween drain holes so any moisture gets funnelled down the holes. Maybe a screwed on plastic shield to direct water off the rear tires away from the holes.

The lower rear area of the front fenders is another water trap.
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I used the dupli-color spray in bedliner in my ramcharger, the stuff is WAY better than any undercoating and is just over 9 bucks a can... did a floor pan in my valiant with it several years ago, the windshield leaks and while I was deployed it sat with water in it, NO rust. Pretty good bang for the buck... my two cents...
 
I'd put some sort of 2 part coating on there, what ever you choose, use a 2 part and or catalytically cured. For example POR15 is a moisture cured catalititc reaction and most bed liners are 2 or more part reaction based curing.
 
I did use Dinitrol on my car. its waxy stuff that newer dries completly. i have owned this car 3 years and so far its good nice black undercoat that dont get chiped if stone hits.

Best thing about this is that it dont trap water
 
Well, a couple posters on another forum mentioned that if bare metal starts to rust the paint will peel and bubble and you can simply take care of it, while rust can work hidden from view underneath undercoating. I would hesitantly tend to agree, although if not driven in snow or salt I think it might take decades for that to happen. Just wanna do this right, and NEVER HAVE TO DO IT AGAIN!
 
It depends on what your goals are. The best stock looking undercoating is sold by RestoRick. Following his instructions, you can achieve a factory look. If stock appearing isn't a concern, I don't think you can go wrong with bed liner. My Dart will be primer colored paint with body colored overspray on the underside.
 
burdar said:
It depends on what your goals are. The best stock looking undercoating is sold by RestoRick. Following his instructions, you can achieve a factory look. If stock appearing isn't a concern, I don't think you can go wrong with bed liner. My Dart will be primer colored paint with body colored overspray on the underside.
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My goal is not to have a concours resto. My goal is to never have to grind #%*@!! rust off the bottom of this thing ever, ever again. I do not intend to drive this in snow or salt, but one never knows what trail life takes.
It's primarily a show car/tarmac terror build, doesn't have to be PC.
 
mopardrt said:
X Infinity

All of rustoleum's products are the bees knees, great price and perform even better.
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They also stick to light rust like stink on s*it. Very little prep needed. Been a key ingredient in saving Edie's ***.
 
I like Rustoleum products and I like the roll-on Dupli-color bed liner (with chunks of rubber in it). I think these products are designed to remain flexible for a long time. The Dupli-color bed liner is designed to go on over paint.

The factory asphalt-based undercoating on my '68 GTX was cracked and falling off in places by the mid 1970s. I think very low temperatures make the stuff brittle when it ages, allowing moisture underneath when small cracks appear.
 
I was in the rustproofing business a couple lifetimes ago. At the time there were 2 main rustproofers, Dura-coat and Ziebart. Dura-coat had a zinc chromite solution that was the best on the market. Supposedly the zinc would bond to the metal via the chromite solution. The Ziebart was easy to get customers away from as they used a wax based solution. It usually took over an hour to clean the zeibart cars because of the necessary overspray. The Dura-coat if applied correctly had practically no overspray. I lived in Minnesota then, Now I live in AZ and have not given the subject a 2nd thought until now
 
Interesting results..damn near a three-way tie. Also very interesting that NOBODY picked Westley's or similar.....
 
Some food for thought;
Most cars that were undercoated back in the day have not experienced the rust issues that cars without did. I have picked up quite a few older cars and each one with undercoating has not had issues where the undercoating has been applied.
Another benefit is it cuts down on noise. You can use a product like Lizard Skin to cut down on noise and heat, but I am not sure how good it would be as a rust deterrent.
Andy
 
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