Getting ready to weld new rear floor into this '86 245DL. Also will be inserting a long section of the first 8" in from the seam the floor makes with the DS rocker panel. (I bought a formed panel for this for about $55)

Need advice about the following:

1) This replacement panel duplicates various contours of the original floor exactly except the lip that will form the seam with the rocker panel does not have drain slots bent into it. (If you incpect closely, you'll see that these drains are 3/4" long bends in the lateral edge of your floor panel.)

Question: How can I put bends in this 90-degree bend in the edge of the replacement panel to replicate the "rocker" drain slots?

2) My floor was rotted front to rear along the first 4" just inside (medial) seam of the rocker panel. I cut out most of it but could not cut free the first 1/2" of the floor that forms the seam with the rocker panel, where it, too, bends downward. I could grind it off, I suppose. this would let me mate the original downward bend of the rocker panel with this mirrored flange of my replacement panel.

If I do try to mate these two 1/2" tall flanges, how should I weld them so they are fused completely and will not allow rust in this seam? Or, are these made water tight using a seam sealer? It appears the original joining is done with spot welding. But I can't tell how Volvo made the seam totally fused along its entire width and length.

Can/should the original spot welds be replicated? I was thinking about drilling holes through the flange ofthe replacement panel and imitating spot welds by merely applying filler into these "spots"

3) I am totally new to welding (and too dumb to be afraid NOT to try). So far in my reaceacrh I am told to use MIG welding. I have not yet decided between solid wire & gas shielding, or flux-core wire. Should I use short-circuiting methods, or more of a spatter or spray technique?

4) What guage metal am I working with in this floor pan? What does that mean for my welder settings? The welding unit will use 115V household current at either 100 or 200 amp service (depends where I plug it in).

5) Should I attempt butt joints for the edges of the large section of new floor material, or a slight overlap that is welded from above and/or below? if I overlap or seam anything (as in the case of the rocker panel vertical seam), how do I assure that the lap or seam is sealed against future corrosion? Those mating surfaces will be bare metal, and maybe not completeley welded together.

6) My replacement panel is painted. Do I need to remove the paint along the edges where I will weld it surrounding metal?

7) My replacement material for large, somewhat flat portions of the floor pan itself will be cut from panels of a discarded washing machine. (I am going for the "enamel Look"!) Any problems?

8) In addition to disconnecting the car's battery, is there anything else I need to do to prevent electrical damages from welding?