How much is too much rust?

[scottsdale1977]

HI all!  I'm a fairly new member/month long lurker.

 

I bought a 90 Comanche (4.0/5 spd/2wd unfortunately) off a buddy from work for petty cheap to fix the mechanical stuff and use as a cheap daily driver.  The body is pretty much shot, which doesn't bother me that much.  As I told the guy, as long as the frame is solid I"m not worried. (It does appear to be.. there's surface rust but no cracks/holes that shouldn't be there) but after going to brush some surface rust off the floor board and pounding on it a bit I was able to put my hand through.  Judging from what I see underneath and under the rubber flooring (as much as I could pull back) the rust goes up to the tunnel and then it's pretty clean.  I was planning on have someone weld rockers and just grind the rest of the body rust off and re-coat it with rustoleum.  I've never welded anything in my life, so wasn't planning on floors.  I don't mind grinding away/cutting out the bad stuff, which appears to stock at the frame rail.  A guy at the part store said he might be able to, he'd have to see it first.  I'd had to just sell it for parts as it has fairly low miles (70k) but at the same time could be in for a nightmare.  

 

What are your guys/gals thoughts?

 

thanks!  

 

 

 

 

[Big Dan]

The floor boards rusted out are pretty normal for most folks. The first welding I ever did was with the floor. Watch a lot of videos, do some reading and you'll be fine.

[Eagle]

Very typical, and not really that difficult to repair. But ... it does require welding to do it right.

[scottsdale1977]

Thanks for the responses/sorry for the delay.  I was in a minor car accident last weekend (someone backed into me at the gas station), so it was a hectic week.

 

I've got a few leads on people who can weld (professionally) and are reasonable with pricing, so I'll probably go from there.

Big Dan, thanks for the confidence boost!  Did you practice on anything first (ie: scrap/junk metal) or just go to town with your floor pans?  :)  

[Big Dan]

In hind sight, I should have practiced, but no I didn't. I just learned what I could and went at it. You'll start to figure it out as you go. It's not like you can really mess up your floor pan any more than it already is.

[scottsdale1977]

Haha, good point! I just hope I don't sink too much into a truck that's not worth it (stil contemplating selling it for parts).

[87Chief]

For practicing (if you want to) go to jflf.org and go to project kits and get the metal project kit for like $7.50. good size pieces of metal to practice beads on. If it's the floor pan and youw ant to go cheap, get a harbor frieght 90 amp flux core welder. I have one and use it often, it's pretty nice, but I'm thinking about getting the mig170 from them.

 

Like you said, look up some videos and stuff first and you'll be fine.

[Megadan]

With thin sheet like a floor pan you shouldn't really be running beads.  Spot welding the perimeter in alternating locations to prevent heat buildup and warping is the method you should generally use when working with sheet metal.  If you do run any sort of bead, keep it at 1 inch or shorter, and still change locations to opposite areas to prevent overheating the metal.  It's more tedious this way, but you get better results.

[scottsdale1977]

For practicing (if you want to) go to jflf.org and go to project kits and get the metal project kit for like $7.50. good size pieces of metal to practice beads on. If it's the floor pan and youw ant to go cheap, get a harbor frieght 90 amp flux core welder. I have one and use it often, it's pretty nice, but I'm thinking about getting the mig170 from them.

 

Like you said, look up some videos and stuff first and you'll be fine.

 

Thanks for the tip!  & Youtube is wonderful for learning almost anything.  

 

 

With thin sheet like a floor pan you shouldn't really be running beads.  Spot welding the perimeter in alternating locations to prevent heat buildup and warping is the method you should generally use when working with sheet metal.  If you do run any sort of bead, keep it at 1 inch or shorter, and still change locations to opposite areas to prevent overheating the metal.  It's more tedious this way, but you get better results.

 

If I'm thinking correctly, spot welding is where you drill holes and weld at those points?  

 

 

Thanks again for all the input guys; appreciate it! 

[Megadan]

In this instance there would be no holes.  You would essentially weld a spot between the two panel edges to connect them together.  if you search youtube for vids on welding sheet you will see lots of people use this method 

[1989 comanche mj]

That is not as bad as mine.  Before you do any cutting get replacement pans and set them on top.  Draw around them with a marker, and cut the rusted metal away leaving a good border for the new ones to overlap.  It is a lot of fitting cutting and hammering to get it right.  Once you get them to fit ok, you can hold them down with self drilling screws and have someone else weld them in.  All the labor is in the fitting, the welding part is quick.   You spot weld which is put your mig tip right near the seam then weld until you get a bead that holds both parts together.  Do these about 8 inches apart, and switch spots, you don't want to build up heat, thin metal warps.   then go around again and put more spots in between.  I am happy if I get a spot weld about every 4 or 5 inches.

 

 

Spot welding can be through a drilled hole, or a hole clear through.   It can also be done with a spot welder, it looks like a big vice grip unit, it clamps the metal together and runs current through both sides to melt the metal together.  This is the way most of the jeep body is built.  I put my pans in with self drilling screws.  Once I get the perimeter spot welded, I will pull out the screws one at a time then stick the mig wire right in the center to fill the hole and weld both pieces together.

[scottsdale1977]

That is not as bad as mine.  Before you do any cutting get replacement pans and set them on top.  Draw around them with a marker, and cut the rusted metal away leaving a good border for the new ones to overlap.  It is a lot of fitting cutting and hammering to get it right.  Once you get them to fit ok, you can hold them down with self drilling screws and have someone else weld them in.  All the labor is in the fitting, the welding part is quick.   You spot weld which is put your mig tip right near the seam then weld until you get a bead that holds both parts together.  Do these about 8 inches apart, and switch spots, you don't want to build up heat, thin metal warps.   then go around again and put more spots in between.  I am happy if I get a spot weld about every 4 or 5 inches.

 

 

Spot welding can be through a drilled hole, or a hole clear through.   It can also be done with a spot welder, it looks like a big vice grip unit, it clamps the metal together and runs current through both sides to melt the metal together.  This is the way most of the jeep body is built.  I put my pans in with self drilling screws.  Once I get the perimeter spot welded, I will pull out the screws one at a time then stick the mig wire right in the center to fill the hole and weld both pieces together.

 

Interesting.. thanks for the info!  My father did body work for a living but I unfortunately never learned it, other than helping sand, so I've never welded anything before.  Though maybe I will do like you said and just get it in place temporarily and have someone with experience weld it in.