Body work question

I own a unibody car, (1991 Isuzu Impulse) I need to replace the rocker panels on both the driver and passenger side of the car, I have talked with a couple different shops and was quoted $1200 to have the rockers replaced and a rear floor pan replaced (jackstand slipped and crushed the floor) that is a little steep for what I am able to afford right now, so I would like to try replacing the panels myself...

Now my question is: -How hard is it to replace rocker panels? -Now being a structural member of the car; is there anything that I have to be cautious about when replacing the panels? -And is it possible to repair the rocker panel if there are a few sections to replace? -Or is there anyone in the Central Ohio area that would be willing to do the work on the side for some cash?

Any help would be greatly appreciated!! This car has been sitting for 2 years because of the body issues, I really would like to try to get these figured out...

If it is just the outer rockers, it is pretty straight forward. What is your skill level at welding and do you have a mig? If the structure is seriously compromised, it would best be done by someone experienced and properly equipped.

rockers might not be as structural as you think. Usually there are "cosmetic" with the real support behind them. Should just be a matter of cutting and welding them up.

As for the floor being crushed..as long as it is not punctured or rusty.. I would just pound it back into some resemblance of normal shape and leave it at that

The rocker "skin" is one thing, the entire panel may well be another. I am intimately familiar with the rocker panels on my '66 chevy II, and I can state that they are most definitely "structural".

I'd be willing to go out on a limb and say that in many if not most cars, the rocker panel is one of the most significant structural members in the car.

This decision should be completely based on if you trust your welding skills.

Can you even get replacement panels for that car? If the shop has to make them from scratch then the price isn't that far out of line.

Before you commit to anything, climb under the car with a screwdriver and see how many holes you can punch/scrape/chip in the inner panels. There are several layers,and for the car to function properly, it needs them all.

second- do you own a mig welder, and do you know how to use it?

Just do like they do on Jeep Cherokees, cut out the outer rocker and weld a piece of square tube in there.

Rock sliders ftw!

http://www.madxj.com/MADXJ/technical/technicalfiles/ARrockerPanels/RockerPanels.htm

I feel that my skill level is pretty good, I have used mostly arc welders though, I do have access to a mig welder but no gas though... I figure keep the amperage down and take my time that I should be set... There actually is not any replacement rockers available for the car, however the Geo Storm shares quite a bit of sheet metal with the Impulse... Yeah, I do need to get under the car more to check out the rust more, I did notice everything between the frame rails is very clean, so I am hoping to get this rust fixed this summer so that I can drive the car for the first time in 2.5 years... How do you guys feel about undercoating? once I get the rust taken care of; I think I want to use some undercoating to help prevent the rust from coming back... Especially when I am planning on keeping this rare car for quite a long time...

One thing we learned from our '09 Challenge build is that body work's real easy if you've never done it before.

Under coating quite often will cause a panel to rust. Be aware that most rust comes from the inside.

I would like to slow the process of rust if I could, I have heard good things about undercoating, I would like to try POR-15 sometime also... see if that helps also...

I am planning on having all of the subframes powdercoated also...

POR-15 has worked well for me in the past. A 110 mig is ideal for this job. If the part is relatively simple, it may be time to invest in a press break.

The offroader in me is not a fan of powdercoating - especially in the rustbelt or on components that can get chipped. One small chip, rust forms underneath the coating and it flakes off in chunks. A spray bomb epoxy or hammered finish seem to hold up pretty well to getting beat on by rocks and trees and touch ups are a rattle can away. OTOH, the undercoating was what was holding the floor together on my mg - it has its uses.

1988RedT2 wrote: The rocker "skin" is one thing, the entire panel may well be another. I am intimately familiar with the rocker panels on my '66 chevy II, and I can state that they are most definitely "structural". I'd be willing to go out on a limb and say that in many if not most cars, the rocker panel is one of the most significant structural members in the car.

Truth. The rocker is generally two basically C shaped sections with a vertical web between them.

This makes an extremely strong member in every direction. If you cut this apart for repair, you really need to know what you are doing. i recently had to repair a set of rockers on a '65 Spitfire which had been poorly repaired by a DPO. When you sat in the car, you couldn't open the doors.

would it work if I were to drill out the spot welds and weld an entire piece back in? I will get some pictures here soon for you guys to see...

I think this is a job that can be done at home. If you are at all concerned the rocker is structural, you first need to find a way to support the car properly, and try to take the loads off of the rocker. Jackstands are your friend here, as usual.

Remember to remove the rusty bits and clean everything properly before going in to patch/repair. Something else nice to have is access to a sheet metal brake for making bends, but 2x4's and clamps can be made to work.

Your comment regarding welding is a bit worrying however: using flux cored wire on thin metal SUCKS! I have tried on dozens of different machines and have yet to find one that will do an acceptable job on 20 gauge steel using flux cored wire. To me gas shielded is the only way to go for this.

Final thoughts are: are you sure it's only the rockers going? In my experience I've done too many rust repair jobs that looked simple from the beginning and ended up near nightmares. Once you start cutting there is no going back, and you may find more damage than you'd previously thought.

I have been up under the car a few times, and it looks pretty clean, I will have to do the screw driver test here soon to see if it is worse than what I had thought... I do have access to a Gas Mig Welder; but I have to rent it from a local place... My father is good with welding so that does not bother me... I hope and pray that the rust is not a ton worse than what I had thought...

In reply to 4eyes:

I've coated bare cast iron keels on sailboats with POR-15. It is great stuff. But, follow the directions, be thorough, and it should work well for undercoating. As stated above, though, if the corrosion starts from the inside of the vehicle, then you'll have a problem. Think trunk rust, and you have the idea.

freaking canoe