Welding Sills?

[mcmoonter]

Has anyone tried welding the sills on an XM. I understand they should be galvanized. What issues does this raise preparation wise? Mine are a bit 'crumbly' on the passenger side and perfect on the other side.

The car has proved reliable over the last couple of years so think it will be worth having a go at welding some repairs into the sills.

MC

[Andmcit]

A while ago I got persuaded into welding a door pillar hinge back on a Porsche 924 once and had a
pig of a time getting it to arc and weld with the MIG. The only way you stand a chance is to
thoroughly remove the coating protection on the surrounding good metal that you do want to weld
the repair onto - kind of defeating the whole set up really if you want it to be protected for a while
longer!

I have to do one small 4" patch on the nearside of the latest '95 s2 2.5 VSX I got on the forum here
and am seriously considering giving a fabricator the job for the modest money it will cost. I'd actually
pay a pro to do it for the sake of a highly visible repair that would be dressed back and made
unobtrusive.

Well, we'll see, watch this space as I need it done asap. The offside sill is perfect on this one too!

Andrew

This post has been edited by Andmcit on October 25, 2008 08:53 pm

[citroenxm]

Interesting question

BOTH my V6 cars need some welding, and I intend buying myself a welder....

The V6 12v needs the near side cill welding up, my own fault, and my 24v S1 needs the rear ends of the cills welding up...

YES, I think you need to grind back the galv covering to the plain steel, and the same on the car for your earthing point... Remember to disconnect battery..

I have a welder (MIG) on load to me from a friend, and have the urge to have a go on the 24v.. I have some cills cut out of another car so I got the correct shaped metal to weld in...

Incidentally, I had a Xantia in last week which needed the drivers front SEAT mount welding back up... I decided to drill out the spot welds, remove the mounting from a spare car and weld it back into the customers car... I sucessfull achived this DESPITE not removing the Galv covering...

Good luck
Rgds
Paul

[xmexclusive]

Hi All

CAUTION

The main reason for removing the galvanising prior to welding is that when you burn the galvanising off you get some pretty nasty fumes. Do not even consider grinding the finish off the steel without decent breathing protection.

On the question of XM rusting the need for weld repairs are more common than the publicity blurb would have us believe. Cills are very common problems particularly at the ends by the jacking points. The rear cross member at the back end of the subframe suffers as do the bumper fixings and front subframes have cropped up recently. I currently have a M reg 2.5 estate that looks great but underneath needs serious welding in 5 locations just to get it through the MOT this time. So much in fact that I am now considering a body shell swap.

John

This post has been edited by xmexclusive on October 25, 2008 09:53 pm

[citroenxm]

John,

Fumes when welding or grinding... to be honest, I wasn't aware of that, just the fact it may not weld very well...


Paul

[DoubleChevron]

I'm sure the galvanising is very thin, You shouldn't run into to many issues. If your first attempt at welding is going to be a coke can thin bit of galvanised XM, you really are setting yourself up for disappointment.

It is critical that you grind away the galvanising, the fact it's toxic aside, you will NOT get a weld to stick to it, it'll just splatter and pop showering you with red hot welding slag.... Even worst than rusty metal if you forget to turn the gas on.

Do NOT use gasless wire, it's hopeless for really thin stuff. What you want to do is cut the area out, "tack" the new section in, then slowly stitch it together, welding no more than 1/2" runs beads before moving to another area to allow the metal to cool. DO NOT try to seam weld it in in one shot, you will horrendously warp the area beyond repair. The problem with patching is you'll also end up with a patch that is bare metal on the rear side where you can't get to it. Spray some weld through primer over everything, then fill the sills with some lanolin based anti-rust treatment (lanoguard, fluid film etc....). I would seriously investigate using some panel adhesive correctly applied as opposed to welding if your not a good experienced welder !

Welding versus glueing :

http://www.autobody101.com/forums/viewtopi...?t=8093&start=0

seeya,
Shane L.

This post has been edited by DoubleChevron on October 26, 2008 12:44 am

[DerekW]

A couple of excellent pieces of advice there Shane.

Derek

[Andmcit]

And floorpan...

I thought I may as well have the car shaken down with an MOT to determine where I stand
with emissions, brakes and suspension joints etc and the worry I had with the sill is real and
in fact worse than first appeared which isn't too big a deal.

However! Mr MOT man has also pointed out "Nearside front (floor) Suspension component
mounting prescribed area is excessively corroded [2.4.A.2]" which actually translated means
that the whole rolled base of the nearside engine bay bulkhead where it rolls round onto the
floor isn't there any more...

I thought these were supposed to be protected!?

I've scrapped a s2 already and this is a bit flaky and have heard s2's on the forum here
get crusty but I've never had an problems with s1's!

Time to crack out the MIG, or another s1!!

Andrew

This post has been edited by Andmcit on October 31, 2008 10:23 pm

[citroenxm]

Go on andrew! You know a S1 makes MORE sense!!!


Rgds
PAul

[Andmcit]

Damn right! My tentative excursions into s2'ness aren't totally without grief and whilst I can
forgive the buy it or it get's scrapped car, the other a FCSH one owner car with 76k miles has
thrown it own unique s2 quirks at me.

It'll be OK, I'm not having a go at S2's and I'm not at the Wolsely House end of the Xm food
chain either so all the odd never seen before stuff goes with the territory I guess.

But rusty Xm's? Didn't see that one coming...

even though I'd suspected they get crusty sooner. The one I threw away a few months back
was almost complete bodily* as nothing was worth keeping off it - totally riddled with scabby
rust although the 2.1TD auto engine/box were excellent so I kept them!!

Andrew

* I kept the front wings and grille!

[Andmcit]

Guess I'm going to need to take some scary pictures of a rotten bulkhead?

Another issue picked up was binding front brakes. Now the fair mileage the car has covered by me
recently would have bedded idle from standing brakes by now wouldn't it - I'm guessing lazy return
on the caliper springs for the handbrake mechanism?

Andrew

[xmexclusive]

Hi Andrew

From what I have seen I do not think there is any difference between the Mk1 and Mk2 XM in the rust stakes. All the cars and estates have virtually the same chassis, the same steel sections and the same treatment. Road salt rusting seems to affect the chassis projections for front and rear wings/bumpers and also gets at the underside particularly the area behind the fuel tank. Unprotected metal such as the front bumper "U" section and the spare wheel carrier also often suffer badly. Then there is the hidden rusting from the inside outwards from the made up sections. On one chassis cut up because it was bent beyond repair I found both the cills and also the front hollow section across behind the engine full of rust much to my surprise because the external paintwork was still good. In that case it seemed to have started from the seams where the thin plates are welded together so perhaps where the galvanising was damaged in the assembly process. I suspect that this latter problem will take out a number of otherwise good XM's as it is difficult to identify until it is too late to repair easily. One of the estates that has come in recently has similar chassis problems with currently 5 points of MOT failure rusting including your front cross panel problem. I am still pondering its future as it is a car I was intending to keep. If much has to be stripped for welding then it might be more sensible to move the bits to another chassis that is in better condition.

John

[Peter.N.]

I have not so far had any rust problems on my Mk2s although the MOT man did say that there were signs of corrosion on the red estate. You can protect the sills and surrounding area quite simply by removing a screw from each end of the plastic trims on top of the sill, below the doors and squirting the contents of an oil can into the holes. This only needs doing about once a year and takes very little time for the protection it gives. I can see under the car where the oil has been creeping into and out of the seams. I also use this treatment on any rusty areas I see when under the car.

I have a cheap MIG welder but I dont find it very good for welding thin metal either. I have though just bought a DC one, a proper heavy one with a transformer and fan cooling, it is so much better as the arc strikes much more easily enabling you to use less current, the only problem is that the lowest current of 25 amps is still to high to make a continuious weld without burning through the metal. I am going to try to find a way of reducing the current further. The welder unfortunatly is gasless but is of very good quality, it was reduced from about £350.00 to under a hundred.

Peter.N.

[robertxmb]

Andrew, if your brake problem is not where you suspect it to be, take a look at the doseur linkage under the scuttle panel. Seize linkage has been mentioned as a source of binding.

Robert.

[xmexclusive]

Hi Andrew

Give it some priority if it is bad as apart from the fuel cost it has been known to overheat and then long tern dry out and kill wheel bearings.

John

This post has been edited by xmexclusive on November 01, 2008 08:36 am