As always, video below so you can see the extent of the issue.

Only rust I’ve found on the car thus far but kind of in a goofy spot.

Repairing rust holes where the backside of the panel is a accessible is one thing, but that’s not an option here so fiberglass+epoxy won’t do. Even just cleaning the spot will prove hard. Thoughts?

 

I'm not a bodywork or restoration expert, but considering the location and size it might be suited to a non-welded repair?
ALong the lines of grind it out with a Dremel tool & burr, vacuum all bits out until it's just shiny clean metal, use rust killer/por15 or similar in the cavity, then you could fill the hole with chemical metal or similar epoxy - I believe they're really good now & don't shrink.

 

It may look minor on the outside, but the inside will likely be a mess. Moisture got trapped there and rust ate its way thru.
The best solution is rolling on a new outer door skin. Body shops do them all the time, and SNG Barratt lists them for the XJS. There are some Youtube videos too. Short of that, cutting out the affected area, and getting all the rust out, and welding in new metal, coating the inside with Por15 or weld thru primer is a way, but likely more work than a new skin. Or buy a good used door from the Southwest.

 

I'm no body guy either, hope that will change and my comfort level will,,, blah blah blah...

That door card has to come off and if the repair is not a weld job, and I would say it doesn't have to be, I would really get in there with different grit sand papers on the end of a good sturdy putty knife and keep jamming it in there and moving it around pretty fiercely. Since there WILL be body filler, I would poke a couple more small holes on the outside and inject some rust killer into the little pocket, clean it out some more. Then pump some rust fighting primer or paint into the void, let dry, then some waxoil, or an equivalent... Then do the cosmetics...

 

Yes, It needs to be sorted properly. Filler is just a bodge. Get a new doorskin or part-doorskin and ensure that the internal door frame is properly sorted.

Good luck

Paul

 

No such thing as a non weld repair for corrosion that has penetrated the thickness of the material, surface stuff yes but that isn't surface. Anything else done to make things look pretty is stop gap, looks fine while the damage continues underneath - and it will because body filler is hygroscopic - it will absorb water, same applies to polyuester based resins and fibreglass etc.

As it stands that has come from the inside, it has to be fixed fron the inside or it needs to be cut out.

Before


Before

During - piece cut out shown

After - no filler used it isn't perfect but I've done the same to the front left 'fender' and that is but I've no pictures immediately to hand, I had to repair the bottom of that, replace the mounting bracket that had long since rotted off.

This blistering comes from below - on the underside



The top of the front left fender (wing to me)

The 'Ex' mounting bracket

All the surface stuff you see here caused blisters on the face of the wing - it had penetrated. All of it was cut out and replaced.

This is the best image I have of the repair to hand. Note that the inner fender has been similarly repaired.

This stuff isn't hard to do but it takes time to do well, and a bit of practice, but nothing to be afraid of. It can seem pretty alien setting about the job with a cutting disc but if a long term solution is needed that is the only way..



You need to stop looking at the face of the door but look inside - that hole is not so minor - it isn't crazy major but anything you do will be back inside a couple of years except worse - needs to be cut out and a patch put in its place.

 

Minor update:

I cut a small opening in the door around the hole (leaving one edge intact) and folded it over to have a better look.

There was a tiny bit more than what I initially saw but it certainly appears to be limited to that one small corner. If I cut any further, I would be intruding into the larger cavity where the window resides - and I already had a look down there. Tiny little specs of surface rust here and there. Was able to scrape those off and find solid metal underneath. Rust seems to be very limited in this case, and it’s no surprise - I’ve done all manner of things to this car over the last several months and found almost no rust anywhere. It’s been in Houston its entire life so that helps.

In the meantime I have inserted a small piece of a paper towel soaked in POR-15 rust dissolver into the area I cut (that stuff is incredible, by the way…did a great job on my fuel sump tank). I’ll let it soak overnight and provide an update tomorrow.

My hope is that it is as limited as it appears. At that point what I will probably attempt is seal all bare metal with epoxy primer and fill it with bondo…the opening I cut will be removed and that will give me clean access to the interior door sheet metal, on which I can apply the bondo. The gap between the interior and exterior door skin in his particular spot is maybe a centimeter, so very little body filler needed.




I’ll add this last thought: if this doesn’t work and that area fails, I can always replace the door skin at that point in time, but I see no reason why my method above wouldn’t work IF the rust is as minor as it appears, and I’m pretty confident it is. We’ll see tomorrow.

 

A very apposite thread for me, as I have exactly the same problem as Mr Anderson in exactly the same place on exactly the same door. Here are the snaps:



These pics were taken before and during the clean up process. Now, not being too fussed about minor non-structural bodywork, I am thinking about doing a bodge unless Paul and Ben shame me into something proper.
After clean up all the loose and rusty metal, I have repeatedly treated the area with a 75% solution of phosphoric acid. This acid east rust, does not attack steel, and leaves a thin layer of some oxide or other of the acid over the metal. Phosphoric acid is the active ingredient in rust killers, but, of course, pathetically dilute in those you buy labelled as such. (I am actually at this point at the time of writing).
Today I intend to treat the entire area with Rust Bullet. Link here: https://www.rustbullet.com/automotive-applications/
This is a rust preventing thick compound and I have had great success with it and the acid treatment before applying, with no show through after 12 years in a similarly water trap area at the front of the rear wheelarch where it ajoins the sill.
My demon plan is, after the RB has cured, to use filler over the top of the RB coat (thus no worries about filler porosity) smooth and rattle can it - thus producing a repair that can only be spotted under 20 yards away!
What worries me about welding a patch in is that I shall so distort the skin surrounding the patch that I will end up with a guastly mess.
Any advice welcomed, Chaps!

 

I would recommend using something like POR 15 putty as a filler instead of bondo. POR doesn't absorb moisture like bondo will. I used the putty to repair part of a rusted rear wheel lip and it could not be told from the metal. Is it a bodge?, kinda, but it should last a pretty long time. I'd probably use a better replacement door for a better DIY repair. You're going to have to paint it anyway.

 

Totally possible, you need to manage heat and cannot weld thin materials like this as you would many others, you need to stitch weld, essentially lots of little spot welds, the joint also needs to be a butt joint not a lap joint, I tend to make the first patch out of cardboard, then cut out the steel to be inserted from new steel sheet and cut the hole to suit.

The area of the door shown by both is challenging, there isn't a lot of space in there, dirt gets trapped in there and does what dirt does especially in a closed space like a door. While I have a section open it gives space to work and you can clean it out, treat the area to a good dose of rust treatment - I use Aquasteel. I then spray on an etch primer followed by an epoxy zinc rich coating. I then grind back to get clean steel to weld to rinse and repeat. Sure some paint burns off it is unavoidable but in areas like this I'd have the door off and would flood the area first with aquasteel and then with a wax - in my case I use Dynax-50 - but something like POR is OK if you can get it thin enough - you need whatever you use to wick into the seams.

I am also not averse to using lead as a filler where needed but again you need to manage heat - health and safetey freeaks need not respond I am well aware of the risks.

One of the biggest challenges for many repairs here is that the joints and areas will contain salts from the stuff they treat roads with and it is extremely hard to remove effectively, it is corrosive and an oxidiser, even high pressure washing doesn't break its 'ionic' bond with steel so the best you can hope for is to keep oxygen and moisture away from it.

Phosphoric acid leaves a layer of Iron Phosphate behind but it is still porous and if sufficient rust isn't mechanically removed you end up encapsulating unmolested rust below it so thinning it and using a wetting agent isn't a bad idea - few drops of washing up liquid. Then don't get impatient and leave a few days in a well ventilated state - not always easy I know but important.

 

Thanks to everyone for the advice. I have ordered some marine grade epoxy putty, and am doing the Rust Bullet today. Will rattle can over the putty.
I completely agree with you Ben that cutting out the old stuff and stitching in new is the real fix; but as you mention, it is a door off job and I do not want to do that particular task right now, as Madame is in the UK and I need a helper. I have just redone all the tractor hydraulic system and my back, arms and hands are crying "enough".
So i will bodge it up as solidly as I can and see what happens over the next few months/years. When it reappears, I promise you and Paul I will do it properly!
Funny, one's psyche, anything mechanical I could not tolerate anything but the best fix; bodywork, not fussed. Takes all sorts I suppose...

 

Not in any way criticising, you know my weaknesses and OCD over such things, the things I've done are because I committed (or should be committed) to doing so, a job that could have taken an hour took a week - some times because I did it more than once - if a jobs worth doing and all that - like I said OCD which is probably why my simple weekend job has now taken two years.

Simply putting forward how I would approach which I understand isn't the only way.

I can 110% relate to that - I really can ....

 

Greg,

As you know better than anyone here, if you seek opinion, the danger is that you'll receive it! And of course, my opinion has extremely limited value anyway!

I've always had a real problem with bodging up sheet metal repairs with filler. I think I still bear the scars as a 14-year old being allowed to try and fix the rust bubbles in the windscreen scuttle on my Mum's Mini. I became expert(!) at rubbing down the rust, getting the profile perfect with the filler, priming and top-coating with spray cans.... and then watching it bubble back through 6 weeks later! It made me decide then that a panel made of metal should only be repaired with metal!

Also, as you well know, all UK XJSs will eventually rot in the bottom corners of the door because of water ingress into the inner door shell. So the idea of sticking bondo / filler etc in there to fix it can only ever be a cosmetic temporary fix that will come back worse. Maybe those of you in warmer dryer climates don't have that problem, but as an ex-pat, you well know the horror of the flange between doorskin and shell on an XJS door and the rust that lies hidden within. So sadly I can never really endorse filler in the bottom of an XJS door!

If I told you I'd fixed a stripped thread with some blu-tac or super-glue and hoped the bolt might stay in there, instead of using a helicoil or recutting the thread, you'd roll your eyes behind the keyboard and do your usual courteous response of politely suggesting I might want to reconsider that approach!

Whatever you do, I'm sure it will look great, and the exemplary mechanical maintenance of your car will forever prevail!

Good luck to you & MrAndersonGCC and send us your pics! Who knows, I may change and become a filler / bondo afficianado?!

Paul

 

I have to agree with Paul but if I guess you have to weigh up the cost, final finish and expected length of time you expect it to last and how long you keep the car for. I had no choice as I'm doing a resto but it may be easier than you think to get a good result. You need a welder though. Here are my doors being processed.

 

Paul
I am under no illusions about what, eventually I shall have to do! But Rust Bullet on top of phosphoric acid treated steel, really can stop breakthroughs for several years; whether it will in this uniquely vulnerable area, I am less confident...
Worst case, more hard work! I really do appreciate your and Ben's advice, and I can assure you, when it has, like a subterranean fire, kicked my subconscious to provoke me into action, I shall be on here for detailed welding and preparation advice.
Herewith shameful and guilt-ridden R. B. first coat application pics (the marine grade epoxy putty is on its way from the Land of the Free):

 

A couple things I'll add:

1. Paul, I really appreciate your posts - very informative. You mentioned that because Bondo is porous the rust will return - but if I am sealing all bare metal in the area with epoxy primer first, then what would it matter if the bondo retained a small amount of moisture on occasion? It's not making any contact with bare metal itself, and the epoxy primer shouldn't mind the moisture. That said - I think I'll also be ordering some POR-15 epoxy putty to use instead - stuff looks very good, and I've no reason to doubt anything POR-15 says about their products. https://por15.com/products/epoxy-putty

2. I have used Rust Bullet before, but only in places where that's the only coating. Even epoxy primer's ability to bond over rust reformer paints is up in the air. I'm prepping the car for a repaint, so I won't be using any rust reformer paint.

 

All paint is porous to an extent, do not underestimate the capabilities for moisture to penetrate seemingly impenetrable boundaries - in much the same way that fuel can escape through rubber hoses - and they ALL do this to an extent. There are a number of camps on the best ways, I use a thinned acid etch as a foundation. I've used epoxies and also zinc rich but even they failed on an old Shogun I had - don't launch boats with any car you care about - sea water will destroy anything.

You don't even need the car to be out in rain, temperature variation will see to it that moisture appears as if by magic - like the condensation that forms on the car - even galvanising has a lifespan and that depends on exposure. The doors on my SV8 are galvanised - they are all corroded through and they're only 14 years old.

 

That is a disgrace, Ben. My 19 year old Ford pickup and my 14 year old Mondeo have no corrosion on them at all. What are these modern Jaguars made of?

 

I agree - I do wonder if the reason so many UK cars rust out isn't just the colder temps and the salted roads that follow, but maybe the air in the UK has a higher concentration of salt since it's an island?

Houston is a coastal city, but it's quite rare to see rusted vehicles around here...my old backup car, a 2002 Saturn my dad bought new, shows no signs of rust on the steel frame despite having 260,000 miles on it.

 

Designed to a price point I guess but not to last. I posted in the XF forums on it but most seem unconcerned - though they should be because it isn't if what will happen will - it is when, in the next year or two a lot are going to wish they had taken notice because the cause can be resolved.

Basically Jaguar applied an anti vibration material to the inside of the door that absorbs moisture, it then holds that moisture against the galvanised surface indefinitely since there is very little airflow to dry the door internals out thoroughly.

You know this is happening because the outer face of the door starts to blister - the cure - get that soundproofing off and get the damn things treated.

X250 Door Corrosion