floor pans

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Tadams

Tadams

Tadams
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I have purchased a new welder and started cutting out the floor pans
any advice for a. Total rookie. I have watched videos and been reading articles. My plans include taking the old pans to practice on. I will have to find the proper primer to use before welding, . After welding, and sealing the seams, will epoxy primer suffice or should I apply a coat of paint before placing a sound and heat barrier. Hope to have this complete in the next couple of weeks. I thought when I retired I would have plenty of time
Doesn't work that way.
 
good heavy welding gloves and an auto darkening helmet! you already got the practice panel thing figured.. you DO have plenty of time - to work on your projects! LOL
 
Lol
I went back to work part time. 2 days a week. Somehow it has turned into 3 days this week
off till Monday which means mow the lawn and then the honey do list begins.
If you are married then you understand
 
I have the helmet and gloves as well.
 
When you weld to the the cross members, drill holes from the top thru the new sheet metal and weld the hole closed, of course over the cross member you are welding too. Dont weld from the bottom with a stitch weld. Metal needs to be as clean as you can get it. Around the edges, just weld a little at a time and go back as it cools off.
 
Thanks everyone. Hope to finish removing the floor pans tomorrow and get everything cleaned up. May have some time Friday to do more. Saturday I have plans to go to Farmington drags and Mopar show.
 
Yup as they say drill through the pans not the crossmembers. Thay way when you weld though the hole you apply more heat to the xmember burning a spot in easier.
 
And that is when my second child was conceived. Lol
 
Easiest is a full pan that goes all the way to the frame rails. Hardest is cutting away part and fitting the new metal to the hole w/ no gaps so you can butt-weld them, especially on the curved tranny tunnel. I did the later, and actually got them butted well after ~10 passes. But, only my 3rd time w/ the cheap HF no-gas flux wire welder, and I got more than a few burn-thru holes. Holding a copper spoon on the backside didn't help much, and hard to do so (magnets). I had to add steel wire filler in places to repair. If I did again, I would overlap ~1/8", making the fitting much easier and also avoid burn-thrus. Nobody will see it under the carpet and I couldn't clean up the underside well anyway above the tranny x-member where you can't access.

Other hints - clean rust and paint the front frame rails and cross-member while they are exposed. I sprayed, then ran a rag soaked in primer (Rust Destroyer) thru them several times. Use "weld-thru" primer anywhere metal will be trapped after welding. High-zinc spray at hardware stores works.
 
Thanks Bill. I'm excited to get this part complete. I will practice on the old pan I'm taking out before I jump on the real thing. I started to go to Harbor tools, but was advised to get a better welder. After I'm finished I'll put it on Craigslist and recoup some funds, unless I have so much fun I want to do another project.
 
I think TIG is less likely to burn-thru. It is more delicate, like soldering on steroids (use both hands). I read the Chinese TIG/Plasma setups work well and are compact, but still pricey (~$350). The biggest problem w/ the baseline HF flux-wire welder is that it only has 2 power settings (min/max, plus wire-feed speed). On min, I have butt-welded exhaust pipes and 1.25" EMT tubing w/ no burn-thrus, but even a little gap gets burn-thru started, and hard to not have some gaps if trying to patch a large section. The trick is to hit it with little "spot weld" bursts, instead of trying to run a continuous bead. Use a drill wire-brush between each re-start. That also gives less warping. The gas flux-wire welders give less spitting. The HF welder has paid for itself many times by doing frame repairs and such. I saw bluing on the opposite side of 3/8" steel when welding tow brackets, so gives good penetration on "max", all from $90 and a 120 VAC outlet.
 
Yep, my plan was to sell it after I finish this project, but who knows. I've thought of a couple of other things I could build. And then again, it is another tool for my cramped garage
 
Pouring rain today will put things on hold. The car is in my garage, but cutting the floor pan is just too noisy. Hope tomorrow will be a better day. Will work on another part of the car today
 
I did the fill welds to the rails and overlapped the edges on mine. be sure to allow enough material when you trim it. if you just sit it in place it will be too small when pushed down. i drew a line with sharpie, take back out to see how much overlap. I then set a cinder block on it to keep it tight till I had a few welds holding to the rails. after done I used neoprene roof caulk underneath and seam sealer inside
 
I have a HF welder and found out use .30 wire for sheetmetal on low setting works pretty well.
 
Thanks for the info
I had planned to roll the car outside this morning and finish cutting the floor out. That would give me the time to clean everything and mark the replacement pans. But with the pouring rain, that project will have to wait for another day.
 
What size holes do you guys suggest to drill through the pans.
chryslerfat said:
Yup as they say drill through the pans not the crossmembers. Thay way when you weld though the hole you apply more heat to the xmember burning a spot in easier.
Click to expand...
 
I did 5/16. also, when you test fit it - get a look underneath to see if you have good frame contact. then draw outline of the rails on the new pan with sharpie so you don't drill any 'air' holes.
 
Use weld through primer between all joints. If you don't it will rust in the seams. NAPA sells weld through primer. Or any body shop supply store. Eastwood does if you shop online.
 
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