Golf GTi Sill Replacement

Golf GTi Mk3 Restoration, Jan-2017

As you can see the outer sill needs attention…

Cutting back the outer sill revealed a lot of rust damage to inner structure:

But it didn’t take too long to clean it up and rebuild the inner structure with some fresh steel (cut from a scrap TR7 boot lid!). In the photo you can also see a clean joggled edge on the remaining upper part of the outer sill. As the upper part of the sill and doorstep was still sound I decided to leave this in place rather than go through the tedium of unpicking dozens of spot welds:

With the inner structure repaired the new outer sill (trimmed to suit the joggled joint) could be tacked into position. Some rivets were needed to hold in firmly flat to the mating edge:

Finally the new sill was seam welded along the upper join and plug welded at the bottom. The upper join was tack welded at reducing intervals until the space between each tack was down to about 40mm. Then I could pulse weld to fill in the gaps. Doing it this way reduces heat build-up and helps avoid buckling the panel:

The join will get finished with a further grind back and then a skim of filler. Some of the floor had had previous repairs using the well-known garage technique of “bodging”. i.e. There was fresh steel welded on top of old rusty steel, creating a moisture trap that accelerated the rusting process. This too had to be cut out:

The worst aspect of these sort of repairs is having to do upside down welding but at least it’s butt welded leaving less chance for moisture to lurk:

Filled & primed with epoxy paint, ready for finishing…

So that’s the driver’s side metalwork on the body all but complete, except to close in each end and drill some access holes where I can inject cavity wax at a later date. Now on with the passenger side.

Update: Decided to see how the car would look with the sills simply painted with stone chip rather than the sill covers / side skirts. Will leave it like this until I get the car on the road when I can have a better look…