How much to cut?

[CEgg11]

Hi all..

72 240, doing floor repair. I bought the car with the area under the seat completely shot, fiberglassed over, every wrong thing you can imagine. The front floorboard looked good.

After removing the rubberized coating, I noticed what I would call pinholes in the floor, up where the passenger's left foot might rest. I have a new full length floorboard ready to go.

So...do I cut the whole thing out, or just weld/POR15 the little holes, and put new metal in the back? thoughts?

Thanks!

[cbuczesk]

If there are pin holes then that area of the floor is already thin. Replace the whole thing and then you won't have to worry about fixing that area later. It's a much cleaner job that way too. You can weld it in at the factory seams on 3 of the 4 sides.

Chuck

[CEgg11]

Agree. Will be easier too, because I wont have to fashion/form metal as much. Will cut it tonight, weld it up tomorrow!

I can weld, but this is the most extensive work I've done. The advice I've gotten is to spot weld every inch or so, and then weld up the gaps between the spots, alternating sides to keep the metal cool. Any other tips? I've seen a guy screw the floor down, then replace the screws with spots, then weld the seams up, but I don't see the need to do that.

[cbuczesk]

The best/easiest way is to get a new floor from Zedd Findings in Canada. I use clamps to hold the floor in place while I weld. I use plug welds on the rocker side, front and rear. I'll lap weld at the trans tunnel. Oh, and plug weld to the frame rail and seat mounts.

Chuck

[CEgg11]

I am working to remove the old seat mounts from the old floor. Other than hammering them out with an air chisel, any other ideas? Those buggers are in there.

[cbuczesk]

Just drill out the spot welds. After you install the new floor you can plug weld using those holes. It's always better to weld onto new metal anyway.

Chuck

[Patcon]

I use a die grinder with a cut off wheel or a grinder with a 4" disk to grind out the spot welds. I grind on the welds from the piece of metal I am removing which leaves the metal I want undamaged and clean. Then on the seat brackets or any other place I need to make plug welds I use a Harbor freight punch tool to make holes or a plasma cutter if they are in the middle of the panel. Spot weld cutters will work if you take your time and use good bits. I am just getting too old to be willing to take that long to drill out so many welds.

[CEgg11]

I drilled/grinded the welds, and I am getting ready to cut out the rest of the floor tomorrow night. Does the front rail/brace need to come out, or can it just go in under the rail? I am attaching pics.

[CEgg11]

Those pics are horrible. Apologies

[grannyknot]

If by "front rail/brace" you mean the front seat support which sits about midway on the floor pan, then yes you can leave it in as long as you grind off the welds on the bottom of it. You can run a couple of self tapping screws through the bottom flange of that seat support and into your new floor pan so you can get a good weld then remove the screws and fill with weld.

[cbuczesk]

Rather than using screws to draw the seat mount and floor together put a factory jack and a block of wood under the floor to push the floor into the seat mount. If there's still a gap you can tap the seat mount down toward the floor since the jack/wood will be bracing the floor. That way there are less holes to weld and grind. :-)

Chuck

[grannyknot]

Rather than using screws to draw the seat mount and floor together put a factory jack and a block of wood under the floor to push the floor into the seat mount. If there's still a gap you can tap the seat mount down toward the floor since the jack/wood will be bracing the floor. That way there are less holes to weld and grind. :-)

Chuck

Your right of course, I was picturing my Z body on it's side on the rotisserie. CEgg11 is probably doing this with wheels on the ground.