While most of the bodywork on XPO was in good condition, away from the A-pillar, not everything was perfect. Some smaller welding repairs are needed. Aside from storage damage, a few key areas of corrosion needed to be tackled. One of these areas was the front wing, and while the wing is only cosmetic, the damage needed repair so the body panel could be safely secured to the car. Then, the rear exhaust hanger parted ways with the body, as is often the case with the BX. And finally, the front towing point, which is unique on the Citroën BX 16V, also needed a touch with the hot metal. Back out with the welder, it was time for more welding repairs.
Front Wing
The front driver’s XPO’s wing was hardly in the best of condition, having suffered some damage during its many years of storage. However, it seemed to be the original to the car and was generally a good paint match to the rest of the car.
Despite the big ding at the front of the wheel arch, I decided to keep the wing and carry out some repairs rather than try to find a new wing to paint.
A tab on the back of the Citroën BX wing should meet a bracket on the car, and the two are secured together with a bolt and captive nut.
In the case of XPO, both the bolt and the captive nut had dissolved. This is fairly common in the UK, and a result of the bolt head sitting in the wheel arch and continually bombarded by weather and salt.
In XPO’s case, the corrosion had crept out from the bolt and into the securing tab on the back of the wing. Rather than try to guess dimensions, the tab was carefully cut off the wing.
The remains of the tab were flattened out and traced onto some CAD paper.
The CAD template was then cut out, and the shape transferred into some steel sheet.
The new tab was offered up to the wing, and thanks to the CAD, the replacement metal was a perfect fit.
Rear Wing
I may have previously exaggerated how bad the rear exhaust hanger actually was. Despite the car’s mileage and history, the bracket was actually fully intact, but clearly not long for this world. It was clear to the eye that it would need replacing.
How much welding repair is needed?
The first step was to remove the exhaust hanger plate. The four spot welds were drilled out at the ‘reinforcement’ plate and removed with the hanger. Sure enough, when the plate was removed, the scale of the corrosion became apparent. Really, this was a poor design as the reinforcement plate is not sealed and traps moisture, resulting in the hideous corrosion normally seen on the Citroën BX.
Out with the old metal
Slowly, the bad metal was cut back to something more structurally sound. Unfortunately, the corrosion had tracked out of the inner wing panel and into the boot floor panel, although not too far. This did mean cutting away more of the inner wing than was strictly needed.
The boot floor was then built back up with new metal. To get a good fit, the inner wing will be spot/plug welded back to the boot floor panel, so it is important to get this small repair reasonably right.
Before starting this repair, I really should have paid more attention to my gas level, or lack of welding gas. These few cup fulls of Hobby Weld did not last very long at all!
Once a new bottle of Hobby Weld had been sourced, welding continued. A new reinforcement plate was made up, and the original hanger glued on, only after a jig was made to get the alignment right.
In with the new metal
WARNING: Look away if you’re offended by shocking welding!
Back under the arch, the inner wing was repaired, Then the exhaust hanger and reinforcement plate glued back in. I’m not really sure what went on with the welding here. I’m never great at verticals, but this was pretty shocking. Fortunately the mess did tidy up well, and will be buried under stone chip.
At the same time, I started to tackle the tail panel. Again, this is a common fail point and quite a bugger to repair, being tight on access. Beyond being super thin and buried in seam sealer, the shaped section is also one of the trains for the sunroof. Care if needed to make sure the sunroof drain water can exist the car quickly.
Much swearing and hole chasing later, and slowly, the holey panel turns into something a little more structural.
From the outside, the repair looks more acceptable. And for the record, yes, the wheel was off when I welded the other side.
The rot had crept from the tail panel into the rear reinforcement bar, so the repairs continued onwards and upwards.
All’s well that ends well
With some grinding back and a heavy dose of etch primer the back end is looking a little healthier. A few layers of paint should see the repair hold for the rest of the car’s life. At the same time all the cavities are treated as well.
Similar finishing stages take place on the inside, along with some Upol Grey Stripe brushable seam sealer. Of the many brands I’ve used over the years, this has become a firm favourite. The sealer brushes on really well and seems to take paint perfectly.
Citroën BX Tow Point
Back to the front of the car, and the last of the welding repairs could be completed. Here the unique Citroën BX 16V tow point needed some attention. Having seen a few 16V’s where the bracket has fallen off, it seemed a wise thing to check over.
Not surprisingly, the load spreading plate, which was welded in place, failed. This is a similar issue to the rear exhaust hanger, where the plate is tacked on but not sealed well and soon rots away. Fortunately, in this case, the panel behind is not too rotten.
After opening up the spreader, I decided I could cut back to some good metal and put in a replacement. This would avoid taking the whole towing eye off, and save a few hours trying to get the alignment right. Once the old metal was cut out, a replacement was made in 2mm steel and seam welded in place. Breaking my own rule of like for like, the load spreader was edge welded rather than spot welded. I’ve never liked the few spot welds being the only this holding the whole towing eye to the car.
Finally, both sides of the repair was given a heavy coating of Vapormatic primer/inhibitor. Enough was applied to ensure that any gaps between the load spreader and the body were well-filled. This is another repair that should outlast the car.
And thats all for this eposide. Next time, maybe we will see if the engine starts?
M
Nice to see progress.
Currently I’m doing a full restoration on a red 16V mk in the Netherlands.
Do you have any downloads for BX wiring, ECU info etc?
Hi Nisse, I don’t host any downloads here (yet). For BX 16Valve information, you can try BX16V.com, which has a lot of downloads for the BX 16v. You’ll need to create an account to access the downloads. M