Rust on tailgate.. what to do

Much to my dismay, my 96 Ex is showing its first signs of rust on the bottom edge of the tailgate. Right now it's just bubbling paint, but it won't be long before the paint breaks off and I have a nice 1" circle of rust starting. It seems like the rust is forming at the bottom edge where the hatch inner and outer pieces of metal come together. If lift the hatch and look at the bottom, there are a series of water drain holes. Apparently they aren't doing their job as well as they should. A couple tiny patches of rust are starting at other spots on the bottom edge as well. What are the options? With 127k miles I don't know how practical it is to throw a lot of money at the body. On the other hand, the truck is in really good shape and I would hate to spoil it by having the hatch rot away. Is there anything I can do short of replacing the entire thing? I know it could be sanded and painted but I don't expect that would stop it as there is obviously a weak point in the design of the hatch so that rust starts forming at this location. Thanks for any input!

Jason

 

[Brock94]

I've just kept after the rust on mine. On mine, the rust did not reach the outside of the hatch, but began to bubble up on the inside bottom edge-- I scraped with a screwdriver to get the loose paint and rust off, used a little piece of sand paper to get some more-- a coat of rust-converter, then a coat of paint from a rattle can-- it doesn't look perfect, but it isn't visible from the outside with the hatch closed anyway, and the rust has at least been slowed down a bit.

I was just patching stuff and hadn't though about fixing the cause. If you remove the inside trim from the hatch, maybe you can access the inside, lower portion and see if water is collecting in there-- then you could rust-convert and paint those areas and fill in with silicone or seam sealer so the water will run out. Hmmm, this is giving me ideas...

 

[F14CRAZY]

My technique (don't know its long term effectivness yet)

Remove the rust/crust. Wire brush on a drill works good. Get it all off. Leave the hard rubber filler goo as much as you can alone. WIpe with rag to make sure it's clean. Spray with a few coats of Rust O Leum "Rusty Metal Primer." Then a coat or two of rust o leum paint, pretty close in color to the body. Then a coat of Mar Hyde paintable rubber under coating compound. Let dry. Then spray paint the body color (I got mine computer matched. Since it's expensive and you can't see it from the outside, a close shade of rust o leum would probably work). Use a couple coats. Then, spray a couple coats of clear coat to seal it up.

There you go. Should be good e nuffer.

 

[F14CRAZY]

If you know of someone that can do it, you can substitute zine chromate in for the primer

 

[MONMIX]

That is a very popular location for rust.
From what I gather from your comments, you are not after long term results.

Basic law number one, rust never sleeps.
The quick easy is the sand the surface to bare metal, NO VISIBLE RUST, prime and paint.
There are better ways, that are more labor intensive and costly
and there are cheaper easier ways.
Your results will fall accordingly.

 

[Brock94]

I've had good results with rust converter instead of sanding everything perfectly. I realize that sanding it all off, using primer, base color and clear coat is the ideal, but it's a lot of work and often affects the surrounding "good" paint making the repair area larger. I know it's quick and dirty, but for me the point is to stop the rust at first appearance so it won't spread. Doing it my way won't result in a professional looking job, but I can be done with a spot in 5 minutes (excluding time waiting for stuff to dry). If I had to do it perfectly I'd probably never get around to it.

In addition to the hatch, my X had a few nicks in the exterior paint that were beginning to rust-- I hit those quickly with a brush on rust converter and brush-on rustoleum (my X is black, so matching is pretty easy). Not perfect, but hardly noticeable and I can rest assured that those spots aren't spreading.

 

[jayhawkexplorer]

Brock, I had the same problem on all 5 of the doors of my Ex. I wirewheeled and grinded them the best I could, then rust-preventer, primer, paint, clear coat over the areas. After a month, there's a small bit of orange color seeping through again. I think I'm just fighting a losing battle, I don't know if anything can really stop it anymore.

 

[F14CRAZY]

Brock, I had the same problem on all 5 of the doors of my Ex. I wirewheeled and grinded them the best I could, then rust-preventer, primer, paint, clear coat over the areas. After a month, there's a small bit of orange color seeping through again. I think I'm just fighting a losing battle, I don't know if anything can really stop it anymore.

Zinc chromate

 

[jayhawkexplorer]

What does it do that is different then a regular primer??

 

[Brock94]

Brock, I had the same problem on all 5 of the doors of my Ex. I wirewheeled and grinded them the best I could, then rust-preventer, primer, paint, clear coat over the areas. After a month, there's a small bit of orange color seeping through again. I think I'm just fighting a losing battle, I don't know if anything can really stop it anymore.

By "rust-preventer" do you mean rust-converter-- the stuff that changes the rust to a black color? I haven't had any problem with it rusting again after using this stuff-- I didn't wire-wheel either. Maybe you got so much of the rust off that the converter had nothing to convert. I think the instructions for that stuff say that there needs to be some rust for it to work right.

 

[jayhawkexplorer]

Yeah I used Rust Oleum rust converter. But the instructions say to get as much as you can off by sanding, etc. Which is what I did. I think my problem is that the rust is inside that bottom edge of the door where the sheet metal is folded up, so there's no real way to fix it besides cutting off that edge and welding in new metal.

 

[frickea86]

i'm also have this problem starting, i'm just keeping an eye on it for now...

 

[F14CRAZY]

Uh, zinc chromate has uh, zinc and chromium in it. It's the real deal. You gotta have a permit to buy it, so its gotta be the real deal

 

[jayhawkexplorer]

Haha..I can't exactly use it then. So I'll try asking some body shop guys I know at work about it.

 

[jayhawkexplorer]

That is a very popular location for rust.
From what I gather from your comments, you are not after long term results.

Basic law number one, rust never sleeps.
The quick easy is the sand the surface to bare metal, NO VISIBLE RUST, prime and paint.
There are better ways, that are more labor intensive and costly
and there are cheaper easier ways.
Your results will fall accordingly.

What would the better, more labor intensive and costly ways? Thanks Monmix.

 

[F14CRAZY]

Well, I'd like to know what a good solution to this small scale rust under doors and tailgates is. I've been having the same problem. Would paintable undercoating do any better?

 

[jayhawkexplorer]

I think you'd only be covering up a problem underneath and it would come back easily.

 

[F14CRAZY]

I was thinking it might help if used with sanding. priming and clear.

 

[MONMIX]

What would the better, more labor intensive and costly ways? Thanks Monmix.

I am not sure what you are trying to ask.

I mean, the BEST attack plan is to buy a new hatch.
Also the most costly. This may be the only option depending on how much rust is present and where.

Plan two would be to cut out and remove about two inches beyond the infected area, weld in new metal, shape, fill it with body filler, prime, paint.

For smaller rust areas there are treatments out there that claim to slow rust, some claim to stop rust but I don't trust such a claim.

Some times you can get away with a wire brush and some primer, but again the key is, if rust is there it will always be there and get worse.
If the rust is removed, then you have bought your self some time.

 

[jayhawkexplorer]

So I'd have to buy 5 new doors. Probably not worth the time/cost. That sucks, I guess I'll just have to wire wheel it down to bare metal, then do the rust preventer/paint/clear coat every 6 months or something. Not much else I can do I guess, but what about this zinc chromate stuff??