Unfortunately, I need to swap out the driver's side fender on my XJR. Some minor rust started developing right at the start of the pandemic (which I immediately hit with rust killing primer and touch up paint,) and has been progressing from behind the fender ever since. I really have not had the spare cash to deal with it properly, and now it is really bad. So I went ahead and bought a PED paint code replacement fender off of eBay. It has faded paint at the top, but it is rust and dent free. Ideally, I would love to have the damaged section cut off of the old fender, and the same section from the donor fender spliced on. That way, I could maintain the correct VIN number on my fender. However, I believe that will be out of my price range, and I don't have enough welding skills to do it myself.

So, back to the original reason for this post. As I understand it, there is some kind of heavy duty sealant applied under the top mounting flange of the fender. A forum post that I read said to cut it, but they didn't mention what type of knife to use. And a video I watched on YouTube didn't mention the sealant at all. Should I go with a standard utility blade, or one of those long and semi-flexible snap blade knives? I'm probably overthinking this, but I don't want to screw it up! Also, would it help to hit the sealant with a heat gun first, or will that just make a mess? Finally, should I buy some kind of body sealant to put on the 'new' fender, or just forget about it?

Thanks in advance

 

As no one else replied to you so far, I'll have a go - guessing...:

Since I did not have to have my X308 fender removed yet, I have to trust your description that there is some kind of heavy duty sealant to be found underneath your anthracite coloured (=PED) fender... you asked, if it helps to heat it up (=use a heat gun). There is one way to find out: Use a heat gun, If it helped, it's the same gunk you find behind the interior door trim attaching the liner to the metal panel and which is also used on X-Type and S-Type to hold the headlights together and to seal them. I can't think of any harm it does, attempting to heat it up. And if heating it up does not help, the stuff one finds on the underbody of a car is normally "underbody paint / rubber paint" and I would think that this could be used as protection under a fender as well. If it was there originally, it's a good idea to apply it. And if it wasn't there originally, but you have it due to a PO (previous owner) having applied this, it might be a good idea in your country (we kind of don't know rust on cars in Australia).

About your faded paint on the ebay fender: I only just today finished spray painting half my latest X-Type (I kind of rescued that poor feline from the PO!).
The whole roof was faded, i.e. sun damaged, i.e. the clear coat came off already for the biggest part, but on that roof I have done pure magic: I spend a lot of time removing the final bits of clear coat off the roof with razor blades without damaging the base coat (= actual paint). And today I sprayed clear coat over it - properly.
Other than that, repaint the fender completely with primer, base coat, then clear coat - in which case it really would not have mattered at all, which colour the new fender came with...

About your VIN number, which - according to your post seems to be on the old fender, which would mean, that there is a wrong VIN number on the new fender...
I'd suggest that even if you had the skills to cut out the old number and insert into the new fender, this might be illegal. My suggestion: Before you swap the fenders, go to to that authority in your country, which is allowed to meddle with VIN numbers, show them the old and new fender, show them your paperwork and and have them "stamp out" (=invalidate) the VIN stamped into the new fender and have them stamp the correct (=old) VIN number into the new fender and have them supply you with the documentation.

 

I would strongly recommend more thought about the VIN number on the fender, as Peter suggested. If you ever sell the car, especially if it goes out of state, a law enforcement inspection will likely be required in the new state prior to registration, and it will cause a problem for the buyer, which will ricochet back to you as the seller.

A workaround might be to consider keeping the old fender on hand. That will give you the option to someday cut and weld the fenders like you mentioned (to save the VIN). Or if you do sell the vehicle, you could let the potential buyer know about the issue and you would have the old fender to go with the car. Even if you sell it in-state, the next owner may try to sell it out-of-state, and the VIN issue may still end up coming back to you to help resolve it. Just some thoughts for you.

 

@Johnny B.: When I replied last night, I was relying on the information in your question being correct - but I actually wondered a bit as to why any manufacturer would place a VIN number onto the fender... - Because, obviously, after every fender bender you would face a big problem with the VIN number...

Are you sure there is a VIN number on your fender? Can you send a picture? I just had a look at my X308 - there is no VIN number on the fender, which I can see...

 

On USA models, there should be a VIN label on the door:



There is also a number of Anti-Theft Labels (I think Johnny B refers to these, on top of the fender):



Otherwise, the stamped VIN is at the battery:

 

swap and touch up the fender. On a 22 year old Jaguar there should be little new rust if you forget to caulk the body parts (pull off the old fender, most of the old dried out caulk will come with it, scrape off any remaining, bolt up the new fender -- caulk if your OCD is bad). Nobody tracks VIN numbers on replacement body parts (if in doubt, walk down the street to your closest body shop and ask them!). It's an old car, take the line of least resistance to keep it going.

Now if this car was being preserved for car shows, have the old fender repaired and professionally painted . . . IMHO.