Newbie body man and body filler

What happens if I take my time and s***ch weld it and end up with oil canning? In this case what would I have done wrong and does the hammer and dolly bring the panel back to normal?

 

Whenever you weld, you will get distortion. You can control the amount of it, a little, by tacking, and s***ching, letting the metal cool enough between s***ches. Not real sure about forced cooling, I'm not sure it helps, from my own experience.
You "can" correct any problems that welding causes, by hammer and dolly work. But you HAVE to be good at it...at least on a panel with little shape, or curvature. A beginner is going to have a tough time of it! Even pro's do sometimes!

 

Go find you an old hood or fender that has the same compound curve that you need. Look in the s**** pile at a local body shop. Cut the patch out just slightly larger than the mess you have now. Hold it over your previous repair, and scribe a line all the way around it with a sharp awl. Cut the scribe line as perfect as you can with a good pair of snips. Use the **** clamps as described above. Tack each corner first, and then move slowly around the patch and make small tack welds. Do it slowly, and don't overheat the panel. Take breaks, and if the panel sinks anywhere, bump it out flush before welding any more. You won't need to hammer on dolly anything, if you do it right. Take your time, do it right, and you won't need a whole bucket of mud to fix it when you are done. Don't "s***ch" anything, use small tacks and move to the other gap in between tacks, letteing things cool in between tacks. Keep making tacks till they all touch to form one weld...

 

You are at the start of a build correct? Why start off with a bad repair? If the waves in that panel show up that well in a pic it has to be fairly bad. A lot of guys think they can do their own body work because it is cheaper. In the long run after you buy all the tools and materials doing one job will not recoup your money if done correctly.

That said I would cut out what you have there. Hammer and dolly the edges of the remaining panel. Lay a sheet of your cut to size panel over the opening. Scribe around the panel. Carefully use a cut of wheel to cut out the overlapped panel. Then get yourself some panel clamps. The metal will conform to the slight contour of the cab if clamps are used. Again go around and make sure that the orig metal and the replacement are flat and aligned to each other.

If you only have a mig that is fine. That panel should take at least an hour to weld allowing proper time between spots and short sticthes to cool so not to warp again.

The chances of getting a mig weld 100% perfect is not gonna happen. Heck to all the bondo haters it is very difficult to get tig or gas welded seams perfect on a large panel. Remember grinding also creates heat and should also take about as much time as welding. Make your welds flat with full penetration not just laying on top.

Wire brush you seams after working as flat as you can with hammer and dolly. The gl*** based products are water proof and less prone to crack and that is why they are used over welds. If you stick with one product there should be no bad interactions.

Guys love to say that they 100% use no filler and that every seam they do is 100% worked flat and complete. Then there is the lead debate. Lead is stronger but also has it's limitations. Show me a paint job that goes from lead to primer to color with no filler to feather or fill imperfections on a large panel that is what would be considered today as perfect.

There are million dollar cars that have plastic on them that will last just as long as lead if applied correctly. There is nothing wrong with using plastic correctly and if they had the technology in the 50's they would have used it.

 

Harbor Freight does not have the sheet metal clamps on their website the only place to get them is in the store. And they are called sheet metal clamps.

 

Thank you to all that have replied and made suggestions. I will cut out the new piece and will start over. I only hope there is enough straight material on the sides to work with, but I think I can make it work. I knew this panel was going to be a challenge and it has been a source of frustration for me. The rest of the cab looks great as I have bumped the dents out to the best of my ability and will need very little filler to finish it. As I said earlier, I hate body filler. I tend to be a perfectionist when it comes to stuff like this and I hate knowing that there has been a repair there. However, I can't easily find 1937 truck cabs everyday that re at least in this good of condition.

I'm still a little confused about how long to wait between welds. On the previous two panels I tacked it in one spot and then moved to a spot on the other side and then jumped around. My question is, how many tacks do I make before I let it cool?<o></o>
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Let the tacks cool until you can touch them with your bare hand. On a panel that size you will be able to do quite a bit while they cool but sometimes you may need to just leave it for a while to let things cool off before you keep going. Don't be in a hurry!

 

Hey,

Got a couple questions..... What are you grinding this repair with? Not a cut-off disc, I hope! Cut-off discs produce alot of heat, and their use is for, well cutting, not grinding! A grinder, eletcric or air powered, and a production disc, 24 or 36 grit resin backed, I'd reach for a 7'' or 9'', but the momma's boy 4.5'' size, that's become so popular will work. Remember, smaller grinder discs run at a higher speed than bigger sized ones, and thus run hotter. If your grinding work is turning the metal blue, you're overheating the metal, and this leads to more warpage.

What are you welding this up with? the smaller.023 mig wire works well for sheetmetal work, as it requires less amps to melt, thus less heat & warpage. The .023 is great for rust repaired sections that are really thin prior to repairing.

Do not use sections of fenders/hoods or deck lids from late model automobiles as these panels may contain HSLA (high strength low alloy) steels, and you don't need that problem compounding your welding job.

The welding panel clamps are okey, but in a pinch, zip (selftapping) sheetmetal screws, with a cleat of metal to bridge the panel from behind, will work. Once the panel is tacked, every inch, or so remove the screws and weld up the holes.

Remember, many small tack welds , each made once the panel is cool to the touch, will yield a fairly straight low/no crowned panel when the welding is completed. Get in a hurry, run hot beads close together, and you'll get what ya have there! My money say's ya won't make this mistake, again, any time soon!

S****ey Devils C.C.
"Spending A Nation Into Generational Debt Is Not An Act Of Comp***ion!"

 

I am using a hobart 135 with .023" wire and it works great for me.

I ground down the previous welds with a 4.5" 80 grit flap disc. It takes of less and the only major heat is from the sparks. I dont let the panel turn blue. Is a grinding disc better to use for this? I only used the cut-off disc for its intended purpose and I dont like using them. I had one explode in my face the other day. Safety first....

In regards to using sheet metal screws and and metal behind the panel. Are you saying to **** the panel in the cab hole and put the sheet metal screw in the gap with the piece of metal behind it or is the screw in the panel itself? Sorry I don't quite understand what you mean.

I could just get the sheet metal clamps, but i'm unsure what they look like. If I go to the Harbor here in Green Bay, they wont understand what I want. If I knew what they looked like I could find them myself.

 

HERE