Body Rust Repair Questions

[kelvinator3001]

Looking to address the body rust my 88 FJ62 has. But I've got some questions first. Here's the main thing: how do you tackle rust when you aren't planning to do a full repaint in the near future? What's the best way to color match the spots that I clean up? Or are you just stuck with splotches of primer?

Is the sequence: sand, ospho, primer?

I don't have a garage, when sanding down and before finishing treating the trust will I need to keep it covered with a car cover to protect from the rain?

Any recommendations for treating the level of rust I've got in the areas that I do?

Here's the rust I've got on the doors around the windows:

 

[kelvinator3001]

This looks to be the worst of it. Bottom right rear passenger. Looks like it's coming from rain that's gotten inside the doors. Other than getting new weatherproofing, what should I treat the inside of the doors with once I clean up the rust?

 

[kelvinator3001]

Hatch has small bubbles. Sand it down and treat?

 

[kelvinator3001]

Gutters pretty much look like this all around. This was obviously repainted at one point. But did the PO just not address the rust? Or can rust creep in like this, coming up from under th paint if it was not there previously?

 

[kelvinator3001]

Last but not least, how should I treat exposed metal like this that hasnt started rusting yet?

 

[cps432]

It’s worse than it looks under the paint. It would be a waste of time and money to half ass it right now and have to do it all again later.

 

[kelvinator3001]

It’s worse than it looks under the paint. It would be a waste of time and money to half ass it right now and have to do it all again later.

Yeah, guess that's my question. How can I do it properly without going as far a full repaint? Does addressing this kind of rust require that extreme of a full repaint?

 

[SteveH]

You have a repaint, and a variety of problems, as you noted.

• The last photo are paint chips that could be touched up. The gray underneath is just the primer.
• The rain gutter paint must be completely chipped/peeled out to evaluate how much more rust is underneath. I would treat the rust with a rust converter compound, the carefully re-caulk the gutters with automotive seam sealer before repainting.
• The door frames will require the chrome to come off and be completely sanded to bare metal, primed and repainted. There is more rust under the chrome trim. You may have to remove the glass and rubber seals to get access.
• The door with hole - remove the inside trim panel, vacuum out all the crud, weld in a small metal patch, paint the door, and then literally smear the inside of the door (bottom channel area) with axle grease. You want all those seams immersed in grease - but only AFTER all resto work.
• The hatch appears to have bubbles in the paint, which is likely rust underneath. The entire hatch really needs to be sanded and refinished.

This truck has sat outside and moisture/rain/condensate is creeping under the paint in many areas. To really stop this in its tracks is a large amount of work and then the truck should (ideally) be parked under cover or in a garage. I don't know of a 'quick and dirty' way to fix the problems you show, sort of just smearing grease on everything except the face of the rear hatch (and wiping off the excess) until you totally repaint the truck.

The essence of stopping rust is totally sealing the steel surface outside (with paint) and inside (with a soft petroleum product). There is no great way to fix your set of problems without an extensive amount of work.

 

[cps432]

I have similar rust issues and I am not even going to bother with it until I have time and money to do it all the right way which will probably require me to buy a second vehicle... gets expensive quick... I also need to replace all the weather stripping and that will lead to carpet which will lead to floor repairs which will lead to sound dampening which will lead to dash restoration etc etc... lol

 

[g-man]

Wait for warmer weather and address it when you are getting ready to repaint the entire vehicle. Rust is like a scab. Once it scabs over the rust itself will slow down further rust. The worse thing you can do is remove the rust and the paint and expose it to more weather. Primer is porous and doesn't offer much protection.

 

[MoaByte]

I ground some rust off the front valance and in a pinch hit it with frosty plasti-dip. It lasted over a year before I peeled it off, primed it and hit it with some paint. I didn't expect it to work very well, but it bought me time.

 

[kelvinator3001]

I have similar rust issues and I am not even going to bother with it until I have time and money to do it all the right way which will probably require me to buy a second vehicle... gets expensive quick... I also need to replace all the weather stripping and that will lead to carpet which will lead to floor repairs which will lead to sound dampening which will lead to dash restoration etc etc... lol

as it always does haha

 

[cps432]

as it always does haha

That’s why I’m starting to think about parking the cruiser, get a little 4 banger pickup, and learn to weld. I know that once I start tearing into the rust I’ll just want to rebuild the whole damn truck. So, might as well, hu?

 

[MoaByte]

That’s why I’m starting to think about parking the cruiser, get a little 4 banger pickup, and learn to weld. I know that once I start tearing into the rust I’ll just want to rebuild the whole damn truck. So, might as well, hu?

Welding the floor sucks. Good place to start though as it will not be seen when you get the carpet back in.

 

[kelvinator3001]

Wait for warmer weather and address it when you are getting ready to repaint the entire vehicle. Rust is like a scab. Once it scabs over the rust itself will slow down further rust. The worse thing you can do is remove the rust and the paint and expose it to more weather. Primer is porous and doesn't offer much protection.

That's really interesting. Never heard that analogy, but makes sense. So don't dig in to anything before I'm ready for a complete repaint? Even the gutters? Right now the main thing is just keeping moisture off by getting a cover and potentially greasing the rusted areas?

 

[cps432]

Welding the floor sucks. Good place to start though as it will not be seen when you get the carpet back in.

I pray I don’t need to do much. I know there’s some rust around the wheel wells but from under the truck I don’t see much of anything. Fingers crossed!

 

[MarkBC]

That rust is worse than it looks. Thank the PO for covering over with paint. The problem is it rusts from the inside and in the cracks, so addressing it on the outside won't last. You need to get inside the door and cut out that bad metal and weld in new stuff. Then clean it up and spray on the inside with a rust converting paint like Eastwood frame saver. Then once that has hardened up after a few weeks, spray in some rust inhibitor. Be careful with axle grease as it can plug up the drain holes which will cause water to fill up tthe door or whatever pocket it's in.

This will be a lot of work. In the meantime I'd spray rust inhibitor on all those areas which will basically stop it from progressing further. Also, your roof gutter leaks need attention ASAP. You can't let the rain continue to seep down there. Make that your number one priority. Unfortunately depending on how far it has gone, you will likely need to remove the headliner.

 

[kelvinator3001]

That rust is worse than it looks. Thank the PO for covering over with paint. The problem is it rusts from the inside and in the cracks, so addressing it on the outside won't last. You need to get inside the door and cut out that bad metal and weld in new stuff. Then clean it up and spray on the inside with a rust converting paint like Eastwood frame saver. Then once that has hardened up after a few weeks, spray in some rust inhibitor. Be careful with axle grease as it can plug up the drain holes which will cause water to fill up tthe door or whatever pocket it's in.

This will be a lot of work. In the meantime I'd spray rust inhibitor on all those areas which will basically stop it from progressing further. Also, your roof gutter leaks need attention ASAP. You can't let the rain continue to seep down there. Make that your number one priority. Unfortunately depending on how far it has gone, you will likely need to remove the headliner.

Rust inhibitor recommendation? Assuming it only works on exposed rust (ie not on the hatch bubbles)?

 

[MarkBC]

Right you'd have to chip off the paint from the rust which I would recommend doing, except for maybe the roof gutters because that will let in more rain. Fluid Film is good.

 

[MarkBC]

Even the new Grenadier has a BMW engine. How much plastic is on that.