Ford Focus Sills & Rear Arch Replacement, Tips/Help Needed

[happypaul]

Hello guys,

I will soon be wanting to replace the Sills and Rear Arches (on both sides) on my MK1 Ford Focus Estate.

The sills are the originals and have clearly lost their will to live, and the rear arches and bubbling, so decided it would be best to do both, and not just the sills.

Did some poking around and the bottom of the rear inner arches that meet the sills (where all the crud and water sits) have given up, which has then led to helping the outer sills along their merry way to rust heaven.

Great Ford ideas having a daft material that soaks water used as the rear arch liners!, so will be going about tidying up any surface rust in that area anyway.

I plan on keeping the car for a couple of years yet as the rest of the car is actually quite solid and its a good cheap runner. But would prefer the easier method to fitting the rear arches, the sills don't seem to sound too hard. I have had experience welding before doing MOT patches and various other bits but never had to do a rear arch panel or full sill.


This method sound good?...

1. Cut off the outer sill, by removing the spot welds along the bottom lip, and cutting along the halfway line as the sills are fine up there, and saves removing the spot welds etc in the door shuts.
2. Cut off the outer rear arch.
3. Then repair any inner sill / inner arch bits (like the bottom of the inner arch where it meets the sill)
4. Fit new sill, cutting to size and butt welding along the halfway point where I cut, and plug weld on the bottom lip
5. Now fit the outer arch panel, getting to size etc... Should I step the edge on the original panel and plug weld the repair panel on (as this part is on the inside of the car, not getting **** wet all the time) and then a fair bit of filler work?
6. Or do I get the panel lines up, cut with a thin cutting disc, and butt weld the whole of the panel? tacking every now and then and keep going till its all welded up? Grinding it all back and fillering?

I will have access to a garage at work soon, and was hoping to be able to do a side in a day! As I need to drive the thing lol. Paint wise will be done at a later date so will just primer and stick some random paint on once the filler was complete!

Any help would be great!

Thanks in advance!

 

[cumbriasteve]

I used to do that sort of work years ago and the method I chose depended a lot on the actual car/shape/amount of damage etc, although I have no doubt some will have a set method.

I am sure good old youtube will have at least a couple of videos on the subject.

 

[happypaul]

Cheers for the reply.

You got me thinking about the shape of it now.
I already have the rear arch panels (2 of each side incase I needed to do inner repairs) and looking at the shape of them I think butt welding would be the way to go, even if the panels warped a fair bit on the arch it's quite a simple shape and could be easily rectified!

 

[rikrobson]

You want to keep as much original metal as possible. However the rot will be more extensive than you first imagine. The sills will be quite thin where the metal has been pressed out. This can make the middle of the sill hard to weld it its also thinned out due to the rot.

a replacement panel can be spot welded as per the original method of manufacture. A repair (part of a panel) needs to be seam weled all round for the MOT.

So technically you shouldn.t plug weld half and butt weld the other half. If the weld is ground down and covered with stone chip they will never know though