false spots & copper plate

Now that the inner sill has been replaced the next step was to put the new outer one on with the joyous knowledge that there would be no preparatory work needed whatsoever - apart from sanding the primer of the faces to be welded and drilling holes for any plug welds. Which is no problem at all. There is always a 'but' however..........

When the spot welds were drilled out of the A and B posts (to separate the last remains of the old outer sill living under the A & B posts and the large bracing-bar welded between them) the parts would not come out. I had used to normal method of locating the spots (which is to rub sandpaper over the area and the welds show as recesses with paint still in them) then centre punched them and cut round them with the spot weld remover. This resulted in the familiar holes but with freash air beind them and the panel still hanging from the actual welds just towards the bottom of each hole so I had to chisel most of them away.

When the new outer sill was offered up the holes which you would normal plug weld through to it were mostly floating above the panel and all there was to weld was fresh air. I therefore used a trick to fill the holes: you can clamp a piece of copper behind the hole and fill it with weld then the copper plate can be drawn away as the weld does not adhere to it.

A post showing spotweld-cutter holes filled in with weld leaving only bottom open to plug weld through

same again with B post. dimples above square plate are ghosts of spotwelds which held series3 inertia reel bracket to sill. oblong plate is copy of series 2 inertia reel mounting point (see '3 into 2 does go' post)

Anyway, after this, the outer sill was welded on but we'll skip that just now and go over to the drivers side to show how the above problem can be avoided. What to look for on these particular ares are bumps directly below the nomal spot weld dimples and centrepunch them instead for drilling out. I can only guess that different shaped spot weld arms were used to reach these areas and they have left 'red herring' dimples above the actual welds. I had repaired the inner sill on the RHS before the LHS but only the bottom 4" or so therefore there was no bracing put in place (as the top of the inner sill kept the B post in place). This gave better access to the A & B post spots from underneath and I drilling them out was quite simple.

RHS A post from below showing drilled out spot weld areas. the 3 at front were done with normal drill bit (there are another 3 of these on the door shut face of the A post) and those at top with a spot weld cutter which leaves a bigger hole. note good condition of inner sill (painted red)

RHS B post showing paint filled dimples which are not the spotwelds! wish I'd realised this before drilling out the A post spots. note repaired bottom edge of inner sill

shot from below. remains of outer sill at RHS B post with actual spot welds clearly visible

rear end of RHS B post showing spot welds drilled out significantly below misleading dimples

front end of RHS B post showing same. also location of twin spots on horizontal face plus two where B post meets outer sill top fange which sits in front on inner sill top flange