Rear floor pan replacement question

[66gt350]

On the wife's 65 coupe, I finally got around to yanking out the carpet to see how bad the floor rot on the rear passenger side was. I knew that there was some rot, when we bought it and the PO gave us a rear floor pan replacement piece. It appears that the quarter window was either left down or leaked at some point.

It appears that the new floor pan is for a convertible, since the tab is bent down and her's is bent up. Here's the new pan:

It's hard to see but it's not down all the way, since the front pan seam would go under the seat riser.

The question I have is should I cut out the floor to match the new floor pan, but that would involve removing the seat riser. Or should I just cut out the bottom of the floor and new pan, and weld just that in?

thanks

 

[mustangstofear]

Just drill the spot welds on the seat riser from the top and draw a straight line from underneath,then butt weld. Like my dad use to say. thats no hill for a climber. Rich.

 

[70_Fastback]

Have you inspected the passenger side floor pan and toe board? That area is prone to rust as well from a leaking cowl vent, etc.

If has any rust, etc - I would remove the seat riser and replace the entire side with a one-piece full floor pan.

 

[66gt350]

The rest of the floor looks good...minus a little bit of just surface rust, which I'll probably just clean up and paint. But the toe area under the heater core looks good. the only swiss cheese is that rear section. If I pull up the seat riser, what is that sealer that is gooped between the tunnel and the riser?

 

[apollard]

I'd clean up all those pans before making your decision. Mine looked like surface rust, and felt pretty firm. A good stiff wire brush in the drill, and they showed pinholes and were not a firm - downright thin feeling.

 

[daveSanborn]

If I pull up the seat riser, what is that sealer that is gooped between the tunnel and the riser?

General automotive seam sealer.

 

[66gt350]

thanks Dave. This weekend, I cut out the old floor and welded in the new partial rear floor pan. I decided to only cut out what was bad, so I didn't have to remove the seat riser.

I guess my next stupid question is: why is there seam sealer there? What is it sealing? I guess that I just don't see a need for seam sealer there...

 

[Midlife]

thanks Dave. This weekend, I cut out the old floor and welded in the new partial rear floor pan. I decided to only cut out what was bad, so I didn't have to remove the seat riser.

I guess my next stupid question is: why is there seam sealer there? What is it sealing? I guess that I just don't see a need for seam sealer there...

The seat riser was welded to the tunnel, but only in spots. Seam sealer was applied to keep moisture from getting into the spaces, causing rust and eventually weakening the weld spots. Normally, Ford applied seam sealer where ever two pieces of metal mated[nb]Get your mind out of the gutter![/nb] to one another.

 

[66gt350]

I guess they must have been running low the day they worked on the wife's car. There's only seam sealer on the tunnel, not the front and back or outer side. Or is it that those side had a tighter fit than the tunnel?

And if it wasn't for the gutter, my mind would have no place to go!!! :lol