Metal work help!!!!!

Having a problem installing a new floor pan and need help. As you can see in the attached pics, I got 90% of the pan beat into shape and welded into place. Using 18ga cold roll steel, the existing metal around the pan seems to be 20ga. On the side next to the tunnel I have a gap of 1/4"-1/2" from the new metal to the old metal. Even using a 5 lb hammer I can't get the metal to flush up so I can tack weld it. Can/should I get a torch and heat the area then pound it into place, or is there a better way. I know nothing about body work and shrinking and stretching metal, except the terms.

Also, using the MIG with .030 alloy wire and no gas - having problems with it burning through. Turned the wire speed up and it helped some, but the old metal burns easily.

From what I can see in the photos, you did not clean the metal very good. It needs to be bare.

I used .025 wire on mine, with mixed gas, but also used a whole bunch of clamps, vise grips, welding pliers, and pipe pole clamps to hold metal into place just before arcing it. Did not need heat, for it distorted things too much. Someone hacked the wheel wells, and I layed a electrical conduit on to the inside, curving it bit by bit to fit the wheel well lip.

I would dump the one wire system, and go to thinner wire and mixed gas.


Wm.

Thanks for the suggestion, will help with the burn through issues.

I am still looking for suggestion on how to get the new metal pan to form to the tunnel. I just bought a MAPP gas rig, planning on heating up the pan and beating it into submission.

put some slits in the new metal then draw it down with self drilling screws, weld the seam and slits up and then remove the screws and plug weld the holes shut

I know nothing about it but maybe the old addage "when all else fails, get a bigger hammer" will work for this situation. Lookin pretty good though from a never done it viewer.

Is your problem a gap between where the metal is to short or is the problem in the overlap area the metal will not lay flat and when you hit the metal it springs and won't bend flat? Hard to tell by the pics.

Thanks Deb, I have never done it either. My son-in-law had the MIG and had done some frame/suspension welding but never sheet metal. It is certainly better than the Fred Flintstone hole that was there before. The jute padding and rust were the only things between the passenger and the road. Now a 250 lb man can jump on it and it barely flexs. Sure wish someone would start making rear pans for 67s, although I guess I don't need one now.
I am going to try the suggestion on slits, screws, etc from one post and the smaller wire from another post. Then time to use Mar-Hyde One Step, FE's 800EZ top and bottom on all the seams and top off with bed liner.

65sbstang,

It is your second description. I can't get it flat against the tunnel so I can spot weld it into place. There is about an 1 1/2" overlap of new metal over the tunnel and I need the entire overlap to lay flat so it can be tacked on both sides for strength. I am not too worried about small gaps between welds, I am assuming the 800EZ seam sealer will keep out any water.

It would be nice if the welds were like a bead and acted like a seam seal also, but that doesn't seem possible with our MIG experiece so far. We seem destined to be dirt dobbers and tack here and there until there are little messes everywhere. But, so far it is holding.

The flux core welder makes it more difficult and messier, get the metal clean clean and start you're arc on the heavier metal and sneak over the edge to the thinner stuff all short bursts. Then you should go back and fill in between you're tacks again short bursts till welded solid. As for closing the gaps as others a have said, self tapping screws to help pull it together, slottting and maybe find someway to pry against the metal to close the gap and tack it.

Mike

Every time you place a weld that metal is SHRINKING... Hat shrinks metal and you should have hit ALL 4 corners then all 4 sides with tacks before doing a complete side like you've done.

Is your NEW pan FLAT adn 1/4" away from teh hump or is teh pan curved up so there is room for a inside adn outside weld?

It looks like it's curved. If so, just flatten it out and forget double seaming that weld to the hump and give it a single.


I also use .030 Wire and no gas, it does fine if you up the speed a bit, and stitch in small spots in different places repeatedly... Allowing cooling and slag removal with a wire brush between. That .030 flux core non gas wire leaves a bit of slag behind.