Replacing lower sill section on dodge dart / valiant coupe

We were slowly working our way over the car rubbing down each panel and checking that everything was perfect, the following drama unfolds from what i saw as a small crack in some unneccesary filler/bog on the underside of the left hand (that's the passenger side in australia!) sill (below the door) section, poked it with a screwdriver and about 10mm of filler/bog fell out, as we've done a lot of work on the car and left no more than 1-2mm of filler anywhere on it, this simply had to go, the fix was fairly obvious, obtain the sill from a donar car - fortunately the insides of these are galvenised when they were shipped over from the US - which meant there was an excellent chance the replacement section would be good as new - even tho it was almost 40 years old

The old section, had lots of filler on it to compensate for a poorly made patch that was not the original shape, but otherwise the steel was in ok condition.. on the outside..
.. however the inside view was not so nice, there had been no seam sealer/fishoil etc applied, however there had been rust converter added to this at one stage but it had dried up, you can see the original section and the patch

So the decision was made to do things properly and head down to Seaford valiant wreckers , they were really awesome help, the guy even lent me an extention cable out to the coupe i wanted to remove the section from, a reasonable price was settle upon and i started removing the sill
one VF coupe sitting ontop of a VF wagon, lovely, just the right working height for the part i want

The removal of that section took about 3 hours, carefully unpicking the whole lot with a spot-weld remover drillbit and then cutting the bottom of the bulkhead and rear sill section, tried to get as much of it as possible so i can always trim it down when i put it back on my coupe.
Oh my god! half the car is missing! - good time to give the innards a few coats of black rust proof gal paint, probably should have had the car sitting on a chassis jig at this stage, but this is a good quality yet backyard repair The replacement section was trimmed to some measurements of the existing panel of the car, then we cut the car to suit the patch, ensuring a nice close snug fit - which gives us a better result in the end, here you can see the part nicely spot welded back in (with the MIG set to high for good penetration and lots of wire feed), measure and cutting was good as the you can see where the two pieces need a good butt-weld to match

i got a really nice bead and excellent penetration along that join, required just a few seconds of grinding for a metal-finish quality result, the same was done on the front section - however the heat on the bottom edge of the outside seem to cause it to shrink as there was some existing stress in the steel due to me not lining up everything correctly, but this was tapped out by brute force with a hammer and tag welded onto it, it might not look pretty - but in the end having less filler is the goal. The weld runs across where the tag has been attached, you can barely tell it has been welded! lovely!
A dirty trick learnt from a good friend, weld on a tag of steel, and use a slide hammer to pull it out, or grip it with your sheeties (vicegrips for sheetsteel) and tap it out - dont smash it out, just keep force on it and keep tapping and the steel will move out on its own accord.

And the new section is in, the shitty bit on the right hand side of the sill is some more filler i found that fell out in the process, this will be dealt with next week, looks like it filler to cover up a patch that shrunk when it went in, front section has been lap-welded and needs a fine skim of filler to blend just right, will let the primer shrink back and take hold and come back to this another day

Final pictues of the repair, the area joining to the bulk head was smoothed out and important sheet steel join lines refined with a little filler to give that OEM look. This area had been porta-powered out since a minor accident crushed part of the sill so the lower part of the bulk head was not without imperfections.




No join lines underneith either! all nicely butt welded and grinded off, welding upside-down is not fun but it is possible.

And finally, the important part, the gap on the door (With the door already lined up to the body) is consistant and follows the shape perfectly.