Rubber windscreen trim deteriorating

[damolong]

My father has a Jaguar XK. He's just washed it and noticed that the rubber seal around the front and rear windscreen appears to be deteriorating - whilst it looks OK and there's no sign of any leaks, if you rub it, even gently, you get black marks on your fingers.

Rather than replacing the seals which I suspect is a big job, I was wondering if there was any kind of coating/sealant that could be applied with a fine brush that might 'seal' the rubber?

Any ideas appreciated.

[PositronicRay]

damolong said:

My father has a Jaguar XK. He's just washed it and noticed that the rubber seal around the front and rear windscreen appears to be deteriorating - whilst it looks OK and there's no sign of any leaks, if you rub it, even gently, you get black marks on your fingers.

Rather than replacing the seals which I suspect is a big job, I was wondering if there was any kind of coating/sealant that could be applied with a fine brush that might 'seal' the rubber?

Any ideas appreciated.

Clean it well 1st, the black stuff may just be dirt. Then apply gummi pflege, you may need a few applications.

[damolong]

PositronicRay said:

Clean it well 1st, the black stuff may just be dirt. Then apply gummi pflege, you may need a few applications.

It's definitely not dirt, it's pure black. Thanks for the gummi pflege recommendation.

[Demelitia]

I’ve found gummipfleger to be ‘ok’ on exterior rubber, still excellent on the interior stuff like door seals etc.
I’ve switched to Carpro Perl for exterior rubber, and generally will try to do a few quite strongly mixed applications.
It dilutes with water for different surfaces and requirement.