Rust Repair And Restoration - Floorpan Replacement

Once all the bad metal was gone, we began prepping the area for the new parts to be welded in. The students sandblasted the remains of the floor and sprayed the perimeter with a zinc-rich weld-through primer. They also punched (or drilled in some areas) holes to plug-weld the metal in place.
Once all the bad metal was gone, we began prepping the area for the new parts to be welded
To get a final fitment before welding it in, we dropped the new panel in place, holding it with vise grips or sheetmetal screws, in the case of our floors. The new panel probably won't fit exactly, so be prepared to do some bodywork. Here, Omar Martinez hammered a section of the new floor to fit the contours of the transmission tunnel.
To get a final fitment before welding it in, we dropped the new panel in place, holding it
Stubborn sections are merely an opportunity to break out our old friend the acetylene torch. Nothing softens metal in a hurry the way a 6,000-degree flame does. Heated up and hammered into place, the new floor soon fit like a glove.
Stubborn sections are merely an opportunity to break out our old friend the acetylene torc

After verifying fitment, the students tacked where the sheetmetal screws had been.
After tack-welding, they proceeded to stitch-weld the panel in, closing up the entire gap between the old and new metal. Basically, stitch-welding is a string of tack welds stacked up one after another. This technique is preferable to a single, continuous weld bead because it puts less heat into the panel, reducing the chances of warpage.
After tack-welding, they proceeded to stitch-weld the panel in, closing up the entire gap
Jason "Mighty Mouse" Tapapia then ground the welds smooth and the floor was ready for finish work. Since this panel will be hidden under the carpet, we only covered the welds with seam sealer. If this were part of the exterior of the car, we'd have gone over the weld with a coat of filler.
Jason "Mighty Mouse" Tapapia then ground the welds smooth and the floor was ready for fini

Finally, the students welded in the seat braces and installed the floorpan drain plugs. The braces were welded in, but the plugs were glued in with seam sealer.
Finally, the students welded in the seat braces and installed the floorpan drain plugs. Th
Though it was mentioned earlier, here's another example of why you should take the time to always check what is behind or under the area you are working on. When fitting the floor, we inadvertently punctured one of the transmission cooler lines with a sheetmetal screw and dumped about a gallon of ATF on the floor within seconds of starting the car.
Though it was mentioned earlier, here's another example of why you should take the time to