Replacing The Outer Sills - Follow Up

I finally finished replacing the sealing strip around the front door. These strips crimp the outer black rubber door seal to the door frame.

Rusty sealing strip....... 

Water creeps up inside these unseen. Don't let anyone tell you they have a rust-free DS if they haven't replaced these!

It was the UK Citroen car Club's 'D rally last weekend and I took the opportunity to order one of the front door sealing strips from Citroen Classics. They are a very awkward shape to post but Citroen Classics usually have a stall of parts for sale at the rally and will bring along parts ordered and paid for in advance. It was too good a chance to miss.

The crimping strips have a 'W' profile to grip the rubber seals outside the doors and the trim inside the cabin. 

The crimping strip is '1' in this drawing

Removing the old section.......

Cutting through the spot welds

...........revealed quite a horror story!

Not what I wanted to see!

Though it turned out it was only really the thin metal crimping strip - the bit I was replacing - that had rotted away. Crumbling pieces of old old dried seam sealant made it look worse than it was and the ridge of the chassis, that the channel fixes-to, was actually in quite good shape once it was cleaned up. 

Even though the strip I'd brought was shaped for the curve of the front door frame, some significant fettling was still needed to get them to fit the curve.

The patch doesn't quite follow the curve

Because the metal needs to be soft enough to be crimped, it's quite thin. Many DIY car hobbyists rely on MIG plug welding. The problem with thin strips are that they are difficult to plug weld with a MIG without burning through. There are modern automotive adhesives that could be used instead but, with the patch needing help to follow the curve of the door frame I wasn't convinced an adhesive would hold it and decided I would spot weld it - just as I had done with the other sections. 

Paint stripped off and ready to weld

I started welding at the top and forced the strip onto the seam as I went along. It was never going to follow the curve 100%, but I was pleased with the result. I plug welded the bottom part where it sits on the outer sill and it was every bit as tricky as I'de been told - especially for a welding novice like me. However i got there in the end and, with this past piece done, I'm one step nearer to painting the front half of the car!

Replacing The Outer Sills

I'm building up to painting the engine bay so that I can put the engine back in plus replace many, many other parts removed along the way.  

Patiently waiting for paint

In the first instance I was planning to paint as far back as, and including, the 'A' posts. I would include the scuttle but not the roof, and I would paint the 'A' posts but not the sills/ door openings. Including the 'A' posts meant including the area where the rubber door seal fits. That had been removed when I removed the outer sills back in May 2020. You can read about that HERE. The upshot of all this was that I needed to finish that sill replacement job before I could do the painting I planned.

I'd cut the new pieces to size.......

I'd replaced the mounts that hold the spring bar. You can read about that HERE.

I re-used the mounts off the parts I removed

And had primed and painted the parts.

Inner faces primed and painted

With the underside and sills of the car stripped and painted (you can read about that HERE) it was finally time to finish the job!

I'd bought a spot welder for some of the repair work and decided to planned to use it for this job - rather than plug welding.  I started by cleaning the surface of the sills on the car.

Preparation before welding

There are pros and cons with spot welding. Once you are set up, the welding is quicker and there is no plug weld head to grind down. However there is more prep......For the electrical conductivity needed to spot welding two flat pieces together, both sides of the two pieces need to be clean, shiny and free from rust and paint. In my case that meant cleaning all the underseal and paint from the underneath edge of the sill lip. All four surfaces got a spray of weld-through primer and finally I was ready.

The parts were carefully lined up to the two vertical ends......

All lined up. Spot welder at the ready

.........and then spot-welded along the top.

Spot welds along the top edge

The spot welds were quick to do and looked neat. Unfortunately, of the four panels I'd bought, the pair of front panels already had holes in them for plug welding. So as well as spot welding them, I also had to plug-weld and grind the holes.

Spot weld and plug weld holes!

The next job was to weld up the vertical and bottom edges. I started with a few tacks and then filled the gaps in.

I took the opportunity to replace the rubber holders in the bottom of the 'C' posts and on the 'B' posts. The 'wings' on these rust and the rubbers fall off. Getting the old ones off is not easy. I found one of the 'C' post ends was quite rusty  - because the bottom of the post was silted up with mud and muck. 

Muck from inside the 'C' post 

What was left wasn't strong enough to weld a new seal holder to. You can buy replacement sections for the bottoms of the posts but I didn't have one and didn't really need to replace it all. I just cut out the bad bits. At least it meant i could drill through the other welds from the inside - leaving the outside intact.

Repairing the 'C' Post

It was all tidied up (I made sure the seal holder fitted inside).......

.........The seal holder was fitted.........

..........And I used the spot welder again.

To cut out the old sills, I needed to butcher the lower section of the channel that hold the door seal rubbers around the door frame.

Door seal holder on a 'B' post

These channels have a 'W' profile with the two arms of the 'W' crimping onto the black rubber outer door seal, and the interior door frame trim.

The crimping strip is part '1' in this drawing.

I'd bought a couple of straight sections when I bought the new sills and now put them to work. 

Door seal channels - ready to go

I was able to spot weld these where they fit over the seam on the posts, but plug welded them to the new sill sections as access was limited. This wasn't easy. the strips are thin steel and very difficult to weld without burning through.

Welding in a door seal channel

There is a section of strip around the leading edge of of one of the front doors that looks very suspect. I wanted to replace that too, but it is on a curve and my straight sections can't be used there. 

Rusty crimping strip on a front door

You can buy replacements that include this area - but it's part of a strip that goes most of the way around a door aperture - waking it expensive and awkward (and costly) to post. It will have to wait for the moment. Another delay to painting the engine bay. Will I ever start!?