various stages of rust damage...need advice

[Cody O Riellerson]

I started a thread on this over in the 70 Tech forums but it is more appropriate here. Basically I'm trying to patch some rust holes in my '85 BJ 70 and keep the decay at bay without getting in over my head or breaking the bank. In the pictures you can see the varying degrees of rust damage in different parts of the body. The most serious is on the rear wheel wells in the cargo area. You can see the hole in one photo. I'm would really appreciate some instruction on what materials to use. I've already gone at the rust areas with a wire brush and 80 grit. I was going to do another swipe with 150 or higher grit. I think I will need someone to weld patches in the holes for me. Can anyone give me a ballpark figure for what it would cost to have someone cut out the rust and weld in some patches? What prep work should I undertake?
This is my first DIY project on the old girl, so I apologize in advance for my total ignorance on these things.

Cheers

 

[bigbrowndog]

Picklex 20 is the best product to use to destroy rust. However do not paint over a rust convertor with an acid based primer, no etch primer or epoxy primer that contains acid or it will peel later on.

 

[Cody O Riellerson]

Thanks BBD,

These are the kinds of things I would never know! What other kinds of primer base are there that would work over a rust converter? Before applying the rust converter and primer I will need to clean the area...what should I use to clean the areas? Should I clean and apply rust converter and straight to primer, or should I clean it again before priming?

Cheers

 

[bigbrowndog]

You can paint straight over Picklex20, that is my understanding. Do not let the Picklex 20 stay on concrete where it spills or leaks onto the concrete or it will mark it. Go to Autobodystore Forum and they will give you the best advise as you guys have a wider scope of products to use than what we don't get in Oz. The owner Len is a good painter and will always answer any question plus all the blokes there help as well. Most of the paints and stuff come under dangerous goods act and cannot be mailed overseas. Helpful stuff there like this also,Spray Gun Adjustments Video

 

[Southeast Overland]

I have had excellent results using POR15. I put it on my Pig probably 3 years ago and it is still doing its thang.

Steps
1) Wire wheel all the rust out that you can. You can paint over rust with POR15 (P.aint O.ver R.ust) but I like to get as much out as possible.
2) Scrub clean with POR's degreaser called Marine Clean.
3) Prep surface with their rust neutralizer, I forget the name.
4) Put several coats of POR15 down.

POR has more steps than other products like RustBullet (I've used both) but I'm happier with POR due to how nice and flat it self levels and how it reacts to multiple coats. Rustbullet didn't like multiple coats as much.

POR doesn't topcoat well - so be careful about that - but it dries HARD.

For your first pic (floor pan) I would do the steps above.

For the second pic (wheel well) I would cut out the rusted through metal all the way back to good metal, get someone to weld in a patch, the POR over it. Seal the seams of the patch if needed too after the POR.

Check out my FJ55 build thread in my signature - lots of rust fixin' pics there.

 

[Cody O Riellerson]

Thanks eventhough, I read that thread for about 3 hours, I'm not at the part where you put on the durabak yet! I am going with POR15 and 2 coats of durabak. I haven't sanded off all the paint or removed all of the factory "sound deadener". Just a chunk where some kind of goop or another spilled through the carpet and melted a patch. Can I durabak over these areas as they are with a good clean? Or do I need to remove all the factory goo to get a decent result? The carpet and "vapor barrier" was also glued down with some sticky black crap... what is the best way too remove this without scratching the paint around it?
thanks for the info...

 

[Michael Hanson]

Sticky black mastic removal use dry ice and chisel. MIke

 

[toomanytoyzz]

Thanks eventhough, I read that thread for about 3 hours, I'm not at the part where you put on the durabak yet! I am going with POR15 and 2 coats of durabak. I haven't sanded off all the paint or removed all of the factory "sound deadener". Just a chunk where some kind of goop or another spilled through the carpet and melted a patch. Can I durabak over these areas as they are with a good clean? Or do I need to remove all the factory goo to get a decent result? The carpet and "vapor barrier" was also glued down with some sticky black crap... what is the best way too remove this without scratching the paint around it?
thanks for the info...

Honestly if you're using this method as a "band-aid" and plan on fixing it by cutting the rotted metal out and welding in new metal later on use as few coats/materials as possible. It's just going to more of a PITA to remove later on. Looking at the pics you may have some other issues going on in the seams. You can see sort of a rust ring above the seam sealer. Rust loves to start in between spot welds and work its way out. Pair that with flimsy toyota metal and you have yourself an oxidation party.

 

[Cody O Riellerson]

Hi Toomanytoyz,
It's not a total strip and repaint, but more than a bandaid. I'm getting the patches welded in on Saturday...then rust-converter and paint the sections that need it and (hopefully) durabak the whole floor to the top of the wheelwells. I just meant I don't want to remove all the little sections of deadener that come from the factory. If I can durabak straight over that stuff it would save me a lot or time.