Rubber seal cracking

[Sandy Gibson]

Anyone know of a treatment to stop rubber seal deteriorating.

Ive got an original Spitfire Mk3 steel hardtop and the rubber seal is cracking slightly.  It’s not leaking and I am reluctant to attempt a replacement as the glass is unobtainable and I don’t want to risk breakage.

Ive got an old tube of windscreen mastic that might help but I wonder if anyone has used something better?

[johny]

Im afraid it depends on the quality of the rubber and to some extent exposure to the elements. Saying that Ive heard of suntan cream being used to reduce UV damage or maybe theres some commercial alternative...

Also seals can look pretty horrible (Ive got a couple of examples) but still not leak especially if mastic was used👍

[trigolf]

You could try Armor Oil? It's an American product designed for plastic and rubber trim and supposedly protects trim from UV exposure. I've used it on my Golf rubber trim and think it works, providing the rubber is in good nick to start with. Obviously it won't restore trim but should help stop it ageing any more from UV. 

[DanMi]

certainly don't disturb that seal unless you have no choice, as I believe that the correct profile is no longer available

[Sandy Gibson]

Think I’ll try and fill the gaps with some windscreen sealant and keep the rot at bay for a bit longer.

It doesn’t leak and normally don’t go out in the rain so should at least look a bit better.

[Colin Lindsay]

There are a few products like Meguairs rubber Rejuvenator or PJ1 rubber treatment that claim to 'penetrate and rejuvenate' rubber seals, but I've no experience if they do more than just shine.

[Morgana]

I think almost any kind of bizarre seal is available from the likes of Woolies Trim, Seals+Direct, Phoenix Trim and many others. I've recently bought a tub of Lanocare lanolin grease which is remarkably waterproof and not noxious like petrochemical greases. As it's safe on rubber and nice on the hands, I'd be tempted to rub some on there and at least fill the cracks a bit with something flexible and removable.

Ultimately, UV degradation will destroy it. If you can see the way it seals, I'm sure even if the original seal profile is not available, something else will do. I'm trying to sort a leak in the gearbox tunnel cover and despite various 'kits' being available, all it needs is something compressible enough to fill the wonky gap. I've also had success with Seals+Direct products where they advise sticking two profiles together if you can't find exactly what you want.

[Paul H]

8 hours ago, Morgana said:

I think almost any kind of bizarre seal is available from the likes of Woolies Trim, Seals+Direct, Phoenix Trim and many others. I've recently bought a tub of Lanocare lanolin grease which is remarkably waterproof and not noxious like petrochemical greases. As it's safe on rubber and nice on the hands, I'd be tempted to rub some on there and at least fill the cracks a bit with something flexible and removable.

Ultimately, UV degradation will destroy it. If you can see the way it seals, I'm sure even if the original seal profile is not available, something else will do. I'm trying to sort a leak in the gearbox tunnel cover and despite various 'kits' being available, all it needs is something compressible enough to fill the wonky gap. I've also had success with Seals+Direct products where they advise sticking two profiles together if you can't find exactly what you want.

I had similar issues with fitting / sealing my gearbox cover in my Vitesse . I made hardboard gaskets to fit the gearbox cover and another for the floor and the firewall . I held these in place with sealant and then fitted rivnuts . One one gasket I glued a section of inner tube . The hardboard gaskets were oversize as my fibreglass gearbox cover didn’t fit . 
Paul