Floor pan replacement

[Msbaugh440]

Will I be able to get a full floor pan in through one of the doors? Am I better off getting something below which has the front and rear all in one piece (this was on classic industries website), or getting the separate panels from AMD?

[Msbaugh440]

Here's the AMD options. I'm guessing I would have to butt weld the two rear foot well panels together, and then lap the front and combined two rear panels together.

[anlauto]

I highly doubt, or would be extremely surprized if Classic Industries sells the three pieces welded together like that. The picture is wrong or they're just showing how they go together.
However, I've been wrong before.

[70 Challenger Lover]

They probably don't come together. The factory designed the rear foot wells to over lap each other in the middle and also at the front main floor panel. There won't be any butt welding if you do entire pieces like that.

I think putting in just a front should go in by itself but I only patched a couple areas of mine so someone else will want to verify this.

[jimynick]

"I bought a nice Blair spot weld cutter and an air chisel so that should hopefully get me started."- good for you! You can buy short, double ended 1/8" drill bits and I'd drill a dimple in the middle of the spot welds to keep that Blair cutter from catching an edge and skipping all over. They also sell some neat 1/2" belt grinders these days and they're the hot set up currently to grind through the upper layer only. A few Clecos will come in handy when laying out your replacement panels. I replaced the front floor and firewall on mine and used a bonding adhesive as a seam sealer which will give you adhesion and waterproofing in one bite. Good luck and, if you haven't already discovered it, don't be too surprised if you find even more rot the deeper you get into it. 

[aussiemark]

I went under the car and drilled holes to mark the cross members then just cut it all out with a cut off disc and was left with strips of floor spot welded to the cross members, inner rockers and floor supports/outer seat mounts. Then mark all the spot welds and carefully grind them down and pull the remaining strips off. I also don't think that Classic industries floor pan comes like that because it will not fit in the car, the full front floor just fits as it is.

[Msbaugh440]

Awesome! Thanks for the help guys! I bet you're right, I'm going to end up with a full restoration by the time I tear this apart!!! Lord Knows id love to fully media blast and re-build it, but it would be 5 years before I'd be driving it again and would probably be the end of my marriage!

I already know that my trunk pan needs to be replaced and one of the trunk extensions has rust... I just don't want to destroy the paint job (it looks great but is obviously hiding some bad stuff underneath). It's an all original body that's only had minor work and a re-paint, never been fully restored. Other than it's a slant 6 that I've put a 440 in!

I just got into body work, I'm no expert, but I recently fixed a lot of rot in an older Cummins truck and feel pretty confident in my welding/fabrication skills.  We'll see where this goes, maybe I should start a restoration thread...

[Msbaugh440]

"I bought a nice Blair spot weld cutter and an air chisel so that should hopefully get me started."- good for you! You can buy short, double ended 1/8" drill bits and I'd drill a dimple in the middle of the spot welds to keep that Blair cutter from catching an edge and skipping all over. They also sell some neat 1/2" belt grinders these days and they're the hot set up currently to grind through the upper layer only. A few Clecos will come in handy when laying out your replacement panels. I replaced the front floor and firewall on mine and used a bonding adhesive as a seam sealer which will give you adhesion and waterproofing in one bite. Good luck and, if you haven't already discovered it, don't be too surprised if you find even more rot the deeper you get into it. 

Those belt sanders look awesome! I've got to have one! Any brand you recommend?

[jimynick]

The industrial ones are stupid priced, but Harbour Freight has one for $38 that seems to have a bunch of good reviews, so who knows? Buy a good supply of belts when you get one as they won't likely be available at Home Depot. 60 and 80 grit would likely do it. 

[aussiemark]

I found the belt sander useless belt kept tearing and flinging off, the spot weld drill bit was the best way.

[70 Challenger Lover]

I found the belt sander useless belt kept tearing and flinging off, the spot weld drill bit was the best way.

I personally found the angle grinder to be very effective. They are $10 on sale at Harbor Freight so you can lean into it and give it the abuse. If the top panel is being replaced, I try to drill with a standard 3/8" bit but only deep enough to touch the panel underneath. Then a cold chisel usually pops it free. Never had great luck with spot weld cutters. I alternate between drill and grinder depending on available space. Someone else mentioned a good idea that I also use. Trim away all metal leaving only the areas that have welds. Easier to work with and provides more room. As you start down a strip of spot welds, use a cut off wheel (fits on a second $10 grinder) to remove strips already freed. I also cut in between every two welds so I can use pliers to twist the piece loose in addition to cold chiseling. Once you find your groove, it's dirty work but you can remove a floor or an upper cowl in an hour or two.

[RUNCHARGER]

I feather them with an angle grinder or zip wheel on it's side as well. I try to grind it paper thin without touching the base metal and then pry the remains off. It's whatever the individual feels most comfortable with for sure. I usually air chisel the big chunks away first so I can finnese what's left.

[70 Challenger Lover]

Your method is probably ideal since you don't disturb the base metal. If I can accomplish that I'm happy as I just take an angle sander to it afterward and clean it all up.