Day three and it’s time to tackle the right hand sill, which has clearly had some pretty poor repairs in the past. As I had a complete genuine replacement sill for this side (part # 76412-K1330), I elected to do this job the hard way and fit the entire panel in one piece. The original sill panel extends up inside the rear quarter and around the lower ‘A’ post, where it’s integrated with the other panels making up those structures. Where the upper seams are welded, there are a total of three layers. At the rear, inside the rear quarter, the sill, inner sill and rear inner side panel (where the window lifter is mounted) are all joined as one with the sill panel being the outer one of the three layers. At the front end, the inner A post and inner sill panels sandwich the outer sill between them at the seam, making the sill quite hard to remove. Removing and replacing the full sill requires a fair bit of care and patience, as you have to pick apart a fair amount of the cars structure around these areas, but it is possible with time and some care.
First of all, as with any panel removal the first thing I do is identify the location of all the spot-welds with a paint marker. I remove the bulk of the sill panel first by drilling out the spot welds along the top, cutting it away around the pillars and along the bottom edge, leaving the bottom seam in place. Due to rust, it’s not usually possible to identify the position of the spot welds along the bottom seam so it’s easier to unpick this seam later using and air chisel and spot-weld drill. As is often the case, as soon as I bent the sill down out of the way I found it to be full of soggy rust flakes. The previous rust preventative clearly hadn’t worked all that well. As can be seen in the picture below right, the old cavity wax has covered the inner sill quite thoroughly but as it’s on top of the original panel primer, the rust has simply spread under the paint rendering the wax useless. This is why I prefer to use cavity wax and underseal straight onto bare metal, rather than painting the surfaces first.
After removing the main bulk of the sill panel, it was time to try to extract the parts hidden inside the rear quarter and ‘A’ post. With a full sill structure, it takes a little effort to identify the relevant spot welds at the upper ends and locate all of them. Inside the rear quarter it is necessary to drill through two layers before you get to the sill itself. Rather than using a spot-weld drill, an ordinary bit can be used, as the holes can be run right through the sills mounting lip, as it will be discarded anyway. The holes drilled though the two inner layers can be later used to re-attach the new sill with plug welds. To make sure I got the spot welds drilled out cleanly I used a 10mm bit. At the front end, inside the ‘A’ post, the sill lip is the center layer so a spot weld drill should be used as the third layer is best left un-drilled. Once all the welds are drilled out, it’s going to take some effort with a chisel and maybe a little more drilling here and there, plus a bit of levering to actually extract the final parts of the sill. Patience is needed here, as it can be hard to get the remaining parts out and you need to try and not cause too much damage to surrounding metal.
Having extracted all of the original sill it was time to asses the inner sill and see what repairs were needed, before the new outer sill could be fitted. Fortunately for me, only a small two inch long section of the inner sill at the rear end, two small bits on the bottom of the lip and the lower front edge need attention. The lower front edge proved to be the hardest part, as I needed to fabricate a slightly complicated panel in order for the repair to be invisible from the inside. To do so meant hand forming the stepped lower lip, a round bead and raised section around the hole from flat sheet. I employed my small metal folder, a vice and some hammers and dollies to make the piece, which was then flush welded in. Welding it from the outside meant the weld didn’t require grinding flat and from the inside the repair would be very neat. Once sanded, sealed and painted on the inside, this repair won’t be visible.
Once the inner sill was repaired, the outer sill could be fitted. As always the mounting flanges were ground back to bare metal and holes made along them for plug welding. The joggler tool I use also has a handy built in hole punch, which is designed for this purpose. It’s quite easy to get the sill up into position and its location can be judged from the placement of holes and tabs, which are used to align the panels in the factory. Once aligned it was clamped in place and the welding could begin.
Having got the sill fitted, all that’s left to do is grind back the welds and complete the repairs to the sill ends. The rear sill closing panel will be dealt with when the wheel arch is repaired. The front end needed a minor repair to the lower front corner of the A-post. Fortunately, I found a complete new A-post and pillar assembly (part # 76200-K1330) a few years ago, so rather than try to fabricate the piece myself, I could simply cut it from this panel. The panel was very surface rusty, so I soaked the repair piece I’d cut in brick cleaner overnight to clean it back to bare metal.
The next area to be tacked is the rear of the sill and the rear wheel arch.