Patch Material - need suggestions

[oz]

Greetings,
I've finally gotten comfortable with my MIG welder to take on the challenge of cleaning up/correcting some of the poor quality floor patches that were put on my car but I'm not sure what type or gauge steel to use.

I have just started this project and this is the first area I've looked at. The floor just in front of the rear torque boxes has been replaced with a thin gauge flat panel (tacked in above the existing panel). The remaining hole on the bottom has been sealed off with body filler. The original floor does not connect to the front of the torque box anymore - the hole is about as wide as the torque box (8" x 8"). I think I need to bridge the hole in the original floor to tie the torque box to the panel that actually carries weight.

What kind of steel should I get? What thickness (gauge)? I want to be able to bend it on a bench vice (to mimic the shape of the original floor) but still thick enough to do some good.

Suggestions?

THANKS!

 

[Fstbk]

Ya know you could just buy a replacement panel and cut parts from it to use...thats a cheap way to go?

 

[oz]

You know what - after I posted my thread I had the exact same thought... The light finally came on!

The floor appears to be a patchwork of flat stock shaped and welded from the inside to make the floor waterproof. For me to 'piecemeal the floor is going to take forever. I'm thinking I may stop at the hardware store on the way home and get a bunch of 3" cut off wheels for my air grinder...

I'd like to just get both full length footwell pieces but I think the tunnel has been patched too. Not sure how to get a whole floor in without cutting it in to 3 pieces... live and learn I guess.

THANKS.

 

[mtaqua]

best would be to get the actual piece. if it is small and or doesn't exist there are a couple online companies that sell sheet metal. it seemed it was cheaper and better than buying a body part and hacking it up. (Can get thicker gauge if necessary, not painted, flat, etc.--> better for me). I am away from home and don't have records, so I can't remember the company, but I think it was cold rolled, not sure on the gauge. I did get some thicker pieces for structural and thinner where I needed to make more bends. Also, best thing I found for removing metal was the sawzall, much quicker than the air cutter.

 

[dagenham]

I believe that a whole one piece floor is a tight fit but it will go in thru the side with all the windows either down or out. If its not that way then they go in through the windshield opening. You have to take the windshield out first though

 

[oz]

So far I've just been assessing what it needs. It looks like flat patches were put in the toe board forward of the front floor pan, along with the front and rear floor pan and perhaps the tunnel. It's quite a 'quilt' under there.

I'm tempted to do the whole floor. I know at least one of the Mustang magazines have done a floor replacement article before. Does anyone know where to find this (or other good) info on doing this job?

Thanks!

 

[stangman16]

I know at least one of the Mustang magazines have done a floor replacement article before. Does anyone know where to find this (or other good) info on doing this job?

Thanks!

Here's an online article: How To Replace Floorpans

 

[jackson0215]

Just a couple of quick notes about the floor pans, the stamp these for a range of years in the cars and just because it says 65 to 70 doesn't mean that it fits all of those years. One of the hardest pieces are the toe boards. I cut and fit 3 sets of these and finally took a hammer to the last one to finesse it into place. Some guys are buying the firewall with the toe board and cutting it down so it fits better.

 

[oz]

I finally got all the interior out and see that it's not as bad as I thought. It appears that the person that worked on it before DID use the proper replacement panels - everywhere except the rear left foot well. They replaced the front footwells and toe boards. The rear right footwell is solid. In the rear left footwell, they just put a large flat panel over the original piece to cover a hole and spot welded it around the perimeter. I'm wondering if the replacement panel was available when they did this repair (early '90's)...
I don't really care that much about asthetics but I see that where the pan meets the torque box, there's really nothing holding the two together as the (6" x 6") hole in the original pan starts at the torque box and goes forward from there.

I reviewed the Mustang Monthly article and it appears that they split the torque box before installing the rear footwell. Does the footwell sandwich between the two halves of the torque box or what?

Another question - whoever replaced the panels before pretty much used a small perimeter spot (bead) weld every 3" or so around the perimeter on the top side. There is very little welding of the panels on the bottom. Is this a concern? Should I add more weld to the underside if possible?

Also, it looks like they cut about an inch strip out across the tunnel at the front, about where the foot well and toe board meet, and replaced it. Can anyone think of a reason they'd do this - other than the obvious 'rust' answer? Nothing in the tunnel is even remotely rusty and it appears that the rest of the tunnel is original. The only thing I can think of is that taking it out may have aided in aligning the replacement front pans...?

And finally, while I have all the sheet metal exposed inside the car, is there anywhere that I should add additional bracing to help reduce the stress in the body? The reason I'm doing all this (patching and adding subframe connectors) is because I've got cracks in the paint at the top of the A-Pillars and on the rear valence between the tail lights which tell me there's too much stress in those areas.

THANKS!

 

[dagenham]

The cracks at the top of the a-pillar and also if it is a coupe in the lower rear corner of the quarter window are typical Mustang problems. The subframe connectors are a good idea. Two other pieces you can add is the monte carlo bar that goes between the shock towers and an export brace that goes from the shock towers to the firewall.
You could also add the convertible floor brace that goes from rocker to rocker that welds onto the seat risers.