Need some more body advice and opinions

[idiocrates]

The tub I'm working on has been worked on before....that's no surprise.....but apparently the PO had no access to a mig welder because here's how he made his repairs...
[url=http://www.flickr.com/photos/22032 ... .jpg[/img]
rt_rear_tub_1 by idiocrates, on Flickr
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I guess brazing was easier then welding? Or maybe he only had a torch and no welder? Whatever. My question is......these fixes are all over the tub.....some are smooth....most are roughly puddled....some have holes through them....they're all over the place in both location and quality.....would you leave these repairs in place and simply bondo over them as they did.....or cut them out and weld in a new patch? Just fyi....I have a mig welder with gas shileding....and a couple of copper bars (actually buss bars but they work well)....clecos....and I'm getting some of the square panel holders. Any opinions would be appreciated.....thanks.

[53a1]

That's no big deal.

Mine had tons of various holes I had to fill. Get a gas/flux mig welder from Harbor Freight (or better if you can). Make sure you get the one that has the lower amps. I don't use gas for holes because I grind them down. For holes 1/4 or over make a little plug out sheet metal with snips. Use copper cap from Home Depot as a backing for filling holes. Clean the bondo out of those holes with a round file before filling. Set welder to lowest setting and feed. Stitch weld until the plug is sealed or hole is filled. Grind flat and skim it with bondo if not quite flat or pin holes still present.

[idiocrates]

Okay....so if you were looking at this situation in one spot.....would it be easier to clean out and fill each hole separately.....or cut a patch and matching hole in the tub that eliminates all the holes and weld the patch in place? I guess I'm asking which would be the better (stronger..not necessarily easier) repair? And, while we're on this.....is there any sort of prescribed order to repair things? I am going to replace the front floors, the rear floor, hat channels, and probalby do the 6" below door strips on both sides. The wheel wells need some work too but near as I can tell the instrument panel insert is okay. wish I qualified for TARP funding....I'd just buy a new tub!!

[53a1]

I would just do the holes. Patching a section is much harder than filling several small holes. You are going to have your work cut out for you replacing all that metal. I would look for a new tub but they are hard to find in decent condition if your not in the south west.

[jam51m38cdn]

No matter which way you go there are some things you need to know about brass, it`s difficult to get a good adhesion to bondo or paint. You have to ruff it up with #36 grit or better yet sand blast the brass, if you don`t and get all the flux off, your bondo will pop or lift right where the smallest spot is. So make sure the brass is roughed up. Jim

[idiocrates]

That's probably just exactly what happened to the PO's bondo repairs....a lot of these spots the bondo was so thick it had popped loose from the metal and/or had cracked and rust was living and thriving behind the stuff. I'm thinking my best option may yet be to use a patching method that removes most if not all of the brass. Thanks for the good advice.

[oilleaker1]

If you haven't already figured it out, a mig welder will simply blow the brass up into white crap and ruin your welding when it hits brass. If the brass repair is solid with no holes, I'd leave it. If the panel is all screwed up and full of holes, replace the whole panel. Bondo is not water proof. In water prone areas, use the fine cut fiberglass filler. It is like bondo, but water resistant. If it is local or a small area of damage in a large panel, cut it out and make a repair piece out of the same gauge metal. Then spot weld it a little at a time to not warp or overheat it. Grind those spots before the next set of spots. Do a little at a time until it's all butt- welded together and nice. Easy as cake, nice as pie! John

[TomM]

30 years ago I only had a torch and I was bubba to my GPW. There is a lot of braze on the tub and apologize for doing it but mig welders were not available for kids yet.
There have been no problems with paint and bondo adhesion in the past 30 years and one repaint. I did blast the tub after doing all repairs so it had a lot of teeth.

But another thing to look for is that braze in the hands of a kid bubba means a lot of heat and a lot of warping so run your hands over those areas and work them back into shape with a hammar and dolly.

Tom

[BullRun]

Also, if you MIG weld use a #14 shield in your welding helmet as the arc from a MIG is at the highest end of brightness in welding processes.

You don't even have to look at the weld while stitch welding just position the tip and zapp! ,while wearing your helmet of course. Also use a cartridge respirator or better yet an air fed welders respirator that encloses the welders face. The 3M Airstream Welding Helmet AH9 is an example of this style of welders helmet. The reason for this is MIG welding, especially with argon shielding gas creates a cloud of ozone in the welding environment that can sometimes cause an allergic reaction characterized by itchy and sore eyes if your eyes are not enclosed within the facepiece. It's not fun. Another option is an extraction unit that will suck up the welding fumes at the source and redirect the fumes away from your work area.

And, if you MIG weld it is worth every penny to get set up for shielded welding with an argon bottle or some other shielding gas. The flux core wire is usually filled with impurities which cause it to excessively smoke and the welds rust almost immediately.

Another excellent investment is a rotisserie which is just a giant welders jig that will save an untold number of back injuries and sprains.

Yellow ink welders markers are also extremely useful for writing notes on the jeep body while you work on it.

Go to a professional welders supply and they will set you up with the right equipment and advice.