Patching/replacing vehicle floor pans?

[MushCreek]

I'm replacing the rusted out floors in my '72 F-250. I bought the individual pans, and cut out the old, and am welding in the new. The question is this- Do I have to have weld bead all around, 100%? Because of the thin metal, I'm just doing zillions of tiny beads. I'd say I'm at 60% filled in. Do I need to get all of it, or can I just cover it in seam sealer and call it done? It's plenty strong at this point. I'm not building a show truck, just a driver.

 

[driftpin]

I'm no expert on this, but I think an eventual continuous bead is what you'd want to end-up with. It should be stronger, and less-prone to leakage over time.

 

[mepstein]

We do this daily on vintage Porsches. Basically weld 1” at a time until it’s connected. Only an inch at a time in different places to let the metal cool and not warp.

 

[unslow1]

Do whatever you want. On some of my daily driver's I never bothered to weld them at all. Just laying the new one over the old with silicone between them lasted many years. Toss in a few self-drilling screws and call it a day. Now on my toys they are completely welded all the way around. I also live in the rust belt and have had to replace pieces on nearly every vehicle I've owned.

 

[chris142]

There's millions of those bumpside ford's around still. Would it be easier to replace the whole cab?

 

[MushCreek]

Sure, for $1000 or so- if you can find one with solid floors. By the time I go out West to bring one home, it's not worth it. Bumps have gotten stupid expensive recently, as have their parts. Mepstein- How are you doing a 1" bead? Mine just burns through if I do more than a little dot. I tried connecting the dots, but can't get my machine Lincoln MIG) low enough for a continuous weld.

 

[Monza Harry]

Sure, for $1000 or so- ...
Mepstein- How are you doing a 1" bead? Mine just burns through if I do more than a little dot. I tried connecting the dots, but can't get my machine Lincoln MIG) low enough for a continuous weld.

What size wire? Smallest you can find for the thin stuff usually. [0.023"] I haven't done a wack of sheet metal but the M.O. of the guys posting it all do it [mostly] 1 dot at a time, heat control is even more than everything on thin stuff. Harry

 

[MushCreek]

All I've got for wire is .030. The smaller stuff would be better, no doubt.

 

[SteveH-CO]

I have done lots of sheet metal work with .030 wire and a Millermatic 175. I will sheepishly admit that I never bothered to try welding on the lowest setting (1 of 10) and when I did, it left nice little welds with no burn-through. I could have saved a lot of time over the years by experimenting with my welder and learning this. I would try to weld all the way around the panel, but certainly if you seal it well and paint the bottom (or grease it), it will likely last longer than you'll care.

 

[dcg9381]

Do whatever you want. On some of my daily driver's I never bothered to weld them at all. Just laying the new one over the old with silicone between them lasted many years.

I bought a used polaris. I found part of a stop sign screwed into the floor boards.

OP, there is a tool for creating an "offset" in the old panel to drop the new panel in. I've done it with **** welds - basically spot welds all the way around, grind, then add sealant. It's not welded continuously, but I'm sure some people do it that way.

 

[isb cornbinder]

I replaced the floor in my '40 Ford with a Bob Drake reproduction floor. I measured the car and welded in cross braces to hold the body straight. The doors never fit properly from the factory, so I jacked the floor apart about a centimeter before welding in the new floor. I have a pneumatic panel punch with a flanging offset combination. I remeasured the body and made a few corrections. The welding started as plug welds at the punched holes in the reproduction floor. When I finished the welding around the circumference, the longest welds were never more than a few centimeters long. I used 3M seam sealer from the bottom. I did not apply seam sealer from the top, so any water entry could dry.
This car body was a total rust free and accident free rare one. I did replace the floor because of OEM press cracking and a little surface pitting around the diver's foot area.. The cracking was the most concerning, for me. The floor was just under $1,000cdn.
The doors close with two firm clicks. The alignment is an even centimeter all of the way around. Time: about 4 days or 40 hours.

 

[Jim greengo]

Do whatever you want. On some of my daily driver's I never bothered to weld them at all. Just laying the new one over the old with silicone between them lasted many years. Toss in a few self-drilling screws and call it a day. Now on my toys they are completely welded all the way around. I also live in the rust belt and have had to replace pieces on nearly every vehicle I've owned.

Ah the good old days of $50 beaters! Hahaha

 

[MushCreek]

I have a flanging tool to do overlapping repairs. I don't like the idea of overlapping, as it creates a space for water to sit. This is **** welding, and some of the gaps are rather large, despite taking great pains for a 'perfect' fit. I'm not a body guy, that's for sure. I need to improve my skills going forward into visible body work, and I figured the floors would be the best place to start.

 

[phred]

As a driver a series of tacks on both sides will be sufficient. If you look carefully must cars are spot welded together anyway. Even the structural sections of unibody cars are not solidly welded. I’m replacing the pans in my 66 f100. Since it too will be a driver i am flanging the panels, over lapping 1/2”. Coating everything with weld through primer and tacking both sides 1/2 apart. Seam seal and a foot coat of paint an it will be good for another 57 years.

 

[MP&C]

I need to improve my skills going forward into visible body work, and I figured the floors would be the best place to start.

That’s what I always say, use those floor pans to practice **** welds so when you have to do someplace where it counts, you’re schooled up.

 

[MP&C]

I replaced the floor in my '40 Ford with a Bob Drake reproduction floor. I measured the car and welded in cross braces to hold the body straight. The doors never fit properly from the factory, so I jacked the floor apart about a centimeter before welding in the new floor. I have a pneumatic panel punch with a flanging offset combination. I remeasured the body and made a few corrections. The welding started as plug welds at the punched holes in the reproduction floor. When I finished the welding around the circumference, the longest welds were never more than a few centimeters long. I used 3M seam sealer from the bottom. I did not apply seam sealer from the top, so any water entry could dry.
This car body was a total rust free and accident free rare one. I did replace the floor because of OEM press cracking and a little surface pitting around the diver's foot area.. The cracking was the most concerning, for me. The floor was just under $1,000cdn.
The doors close with two firm clicks. The alignment is an even centimeter all of the way around. Time: about 4 days or 40 hours.

As much as I tried, I couldn’t make out what you were using for door handles. Picture was a bit blurry.

 

[isb cornbinder]

bob drake 1940 ford door handles - Google Search

The outside handles are OEM reproduction. The inside handles are Billet Specialties, annodised black. The grab handles are BMW 750. I hope this helps.

 

[MP&C]

Was in reference to this door handle.

You can see how it’s hard to make out in the picture.

 

[The Cobbler]

I watch Fitzees Fabrication and used to watch Bad Chad ( since unsubscribed) on You Tube & they both weld everything in solid . 1 peck at a time to avoid overheating

 

[Bert_]

Was in reference to this door handle.

You can see how it’s hard to make out in the picture.

I spent a while trying to make it out also.