The other day I went to replace the tire on my spare (it still had the original Pirelli, and I had a better/newer used one to replace it with) and found the trunk full of standing water. I managed to trace the leak down to this body seam that's coming apart, letting in rain:



What's the proper way to repair this? Do I just jam a bunch of body filler in there? I can see the pinch is bolted together from the inside, so those could be loosened to allow access to the inside of the seam. I also see where it extends to under the rear window rubber surround, so I'll have to take care to seal all the way into there. The RH side seam looks to be headed the same way, didn't let water in when I dumped some on there, but I'm sure it will begin to leak soon.

 

Keep in mind, if you just found it, its been like this for awhile. Be sure to inspect that seam at night using a flashlight...a friend would be helpful as you check from inside and out. I don't know what kind of seam sealer Jaguar uses, but check with Eastwood, they have many body panel products.

 

Bought some of the Eastwood black seam sealer, hoping I can get away without having to repaint it much. I'll probably end up scraping out whatever was in there before, honestly looks like body filler but I hadn't poked too hard at it yet. Shone a light from the inside and couldn't see any light poking out, but I could definitely feel water coming in at the seam when feeling by hand and pouring water over it.

It's definitely been like this for a little while, I could see where the water had been standing before, and the whole spare wheel area was damp, started to get some rust spots... Of course, due to the slant in the driveway, where the water was most likely to pool was under the battery tray where I can't see it. Turned the car around for it to no longer pool under there, and got some rubberized rust encapsulator (also from Eastwood) to help cover the trouble areas in the trunk, and maybe promote a bit of extra sound deadening.

 

Take a hair dryer to that seem to dry it out. Even if you don't have any rain for awhile, that seem can still hold moisture. I would definitely try to apply the sealant from the inside, but also, you can tape off the seam on top and apply from that side as well. Do your cleanup (a damp towel should work) with the tape still applied so when you pull it up you don't get edges sticking up. Basically just like caulking a countertop if you've done that. The taping may take some time, but when you compare it to trying to clean off the residue without it...trust me, its well worth it....time and patience wise.

Eastwood usually has a video on applying such things as well...if not a YouTube vid or two.

 

That’s a tricky problem you have there. If it were mine I would probably try to remove that panel (unless it’s welded in place) and clean up the side areas where the water leaked through because it could be rusty and if you don’t stop rust now it’ll just spread. Then since your car is black maybe just apply some black seam sealer to the top side (like highhorse suggested) in hopes that it isn’t too obviously noticeable.

Also I would remove that rubberized undercoating soon and address that rust properly, I’ve seen many times where the rust just continues to grow underneath the rubberized undercoating and then one day a big chunk will pop off and there will be rusty metal that you can just about poke through. So i’d remove that stuff and take a wire wheel to the rust and clean the area up with a paint prep solution and scuff pad and then hit it with some quality direct to metal spray paint.

As for seam sealer, I believe Eastwood would be a solid choice as would Lord Fusor, and 3m. Those are all pretty good products.