Advice on RUST under Gas Tank

[yoda-g3]

Just pulled my tank out due to a leak, and was not happy to find a good deal of surface rust on the floor boards. (Only a couple small spots went all the way through.) It looked like 5 pieces of cloth were used as padding under there. Nice big rust sponges... (Tank is getting replaced.)

I'm not worried about cosmetics here, I just want to stop the rust, not make things worse. I'm not up to a major 10 step perfect restoration process, but I also don't want a hole in my floor in 5 years. The rest of the rig is very rust free and I'll be leaving the hard top on 9 months out of the year. This won't see river crossings or mud bogs.

So will the heavy duty Rustoleum be good enough for what I need? Will it just trap the rust making things worse? I'm a nube when it comes to rust repair, that's why I bought one that's already been 90% restored...

Here are my pics after a lot of scrubbing with a metal brush, 220 grit sanding, and multiple cleanings of brake clean.

Link to PICS

Also what should I use to put back under the tank when I'm done? I'm assuming metal on metal is bad?

 

[samwise]

I have the same problem, and even though I wont be getting to it until summer, I am curious! Hope it turns out well for you and the pics are always good! I am sure someone in this great place will help! I am in spokane as well, the sun was nice while it lasted!

 

[MarcoPolo]

my tank is not a clay pigeon...

See if THIS helps

 

[yoda-g3]

Sorry I should clarify. I already have a new tank. I'm looking to repair the floor boards. That's what the pics are of.

 

[jeffj40]

I had the same problem except mine looked more like alpine lace rather than finlandia. Anyway, por-15 makes a fiberglass mat material that works pretty good. It works like fiberglass but instead of the resin you use por-15. Looks great and is hard as a rock. They sell a whole kit FLOOR PAN & TRUNK KIT-POR-15 Inc. .When I put my tank back in Ill probably cut strips of inner tube at the contact points that worked on my last 40.

If the metal is reasonably sound their epoxy putty works well too I filled a lot of small holes I missed during my resroration since I didnt want to weld anymore.

 

[Trollhole]

 

[Coolerman]

If you do the Rust Bullet, crawl under the truck and clean the bottom just like the top, then apply the Rust Bullet. If you don't, it will rust through again from the bottom quickly.

For the material between the tank and the floor, use several sections of an old water hose or heater hose about 4" long split length wise. Make SURE to strap the tank down firmly so you don't get wear on it from moving around.

 

[Colorado Boy-74-FJ40]

I put strips of split heater hose on the bottom and the top of the tank to hold it in place so it doesn't rattle and move around. When you bolt the cover over the tank it will sandwich the tank securely. As for the RB fiberglass stuff, let me know how that works. I just used a rust converting primer then shot bedliner over it. Mine wasn't rusted all the way through.

 

[jeffj40]

some pics....

 

[yoda-g3]

Thanks guys! I went ahead and ordered the Rust Bullet today. (Got the starter kit.) It means I won't have it done this weekend, but at least it'll be done right.

What sucks is that the underside is really hard to get to with how the exhaust and transfer case sits, and it has a good coating of grease on it. I might have to put that part of the project off until the summer...

Should I even worry about trying to fill the couple small holes that have eaten through? I was actually thinking of drilling a couple extra so there is more ways for moisture to escape.

 

[FF LC FREAK]

If you don't take care of the rust now (either cut it out or saturate it with a rust covernter and cover it with paint) then it will bear it's ugly head again soon. I'm fighting that battle right now. I figure, since I already have it stripped down this far, I might as well fix it right. I don't want to deal with it in another year or two. Rust sucks. There's no easy way around it.

If you are going to do a resto soon, wait. If not, fix it right while it's apart. Otherwise, you will be tearing into it again real soon to "fix" what you left the first time.

Good luck!

 

[yoda-g3]

If you don't take care of the rust now (either cut it out or saturate it with a rust covernter and cover it with paint) then it will bear it's ugly head again soon. I'm fighting that battle right now. I figure, since I already have it stripped down this far, I might as well fix it right. I don't want to deal with it in another year or two. Rust sucks. There's no easy way around it.

If you are going to do a resto soon, wait. If not, fix it right while it's apart. Otherwise, you will be tearing into it again real soon to "fix" what you left the first time.

Good luck!

Well a buddy of mine came by last night to give me his opinion and it looks like I'm going to suck it up and do it right. Going to bust out the sawzall and drill this weekend and clean it out right then tow it to his place to weld new pieces in.

What do you guys think of drilling additional holes in the corners to promote better drainage in the future? Or will that introduce more moisture from the underside?

 

[LC_Hamma]

I ran into the same problem My solution was to cut out the bottom part & sloping sides & leave enough at the top for the gas tank flange to rest on. Since I wanted rocker panel protection too, I just incorporated underbody skids that protrude from the frame up to the rockers, which protect the tank.