Sealant to Assist Existing Rubber Seals on Lights

Do you know the constituents of petroleum jelly and whether any of them will damage rubber? In general petroleum products damage rubber (neoprene is an exception) but I don't know what petroleum jelly is made from.

I don't know the chemical breakdown, my guess is that you wouldn't want to leave petroleum jelly in prolonged contact with rubber. The rubber will soften and swell.

Definitely don't want to use it with latex.

http://en.wikipedia.org/wiki/Petroleum_jelly

As I said, the existing seals aren't that bad - I'm not looking to replace them - just help them.

As previous suggestion, silicone sealant, or cut sheet EPDM to make auxilliary gaskets/seals (available as pond liner from a pond specialist near you) or old car innertube. Modern cars seem to have a sort of expanded foam sheet seal which is quite thick to take up any missmatch in the components.
Del

Here's what I'd do.

Place the gaskets on a cookie sheet or other flat surface, unrestrained, and warm them up to about 65 °C for a couple of hours. This will help allow the rubber to return to it's original shape.

Then I'd use a thin layer of lubricant, silicone or petroleum jelly. Silicone adhesive will make disassembly more difficult.

If the gaskets are symmetrical, you might consider reversing them.

Good luck.

You don't think petroleum jelly would harm the paintwork? It's a new paint job.

Yes. It might. I'd use just a minimal amount so that none can migrate onto the paint.

I have a black sticky substance called "3M trim Adhesive" which is usually used to hold boot lid rubber etc in place. I'm think a thin smear of that either side of the seals?

I have used the following under similar restoration work. Till recently I was running a 1965 Ambassador car & had to adopt such modifications.

The old rubber seals may appear to be OK, but they would have become hard & brittle; May also have hair cracks.

Alt 1: Use a silicone sealent, transparent one, which is used for sealing cracks in buildings etc.,

Alt 2: Use the teflon tape used for plumbing joints.

YS,
JNB.

The seals are almost certainly EPDM rubber which cannot tolerate exposure to any petroleum based product. DO NOT use Petroleum jelly on it unless you plan on replacing the seals next week.

Use Silicone grease such as Dow 111 instead. It will never harden, should not harm your paint, and will not wash out of the joint. It is also reasonably chemically inert and should not damage the plastic parts either. And it will not melt and flow out of the joint on a really hot day the way petroleum jelly would.

The down side to products like DC 111 is that it renders any surface it comes in contact with unpaintable. Toluene is about the only solvent that will effectively remove it.

Cheers.

Silicone rubber caulk will work well. It is relatively inexpensive, clear (so it will not be obvious) and weathers well

Dear Sir: Take a SPRAY CAN of WD40 & spray on all sealing rubber, If you got enough on anywhere, just wipe it along the seal. WD40 causes a restored to new look & affect to most flexible materials. Call me:" Just an old friend from the Back Shop."

Don't use WD-40 on rubber!!! It contains oil that will severely damage the rubber. Check the instructions on the can and the manufacturer's website.

I agree. Use WD 40 only after determining that it will not degrade the rubber.

The cracks might not appear right away, so be careful.

just boil the seals for a few minutes to reshape and install, if you see any signs of leak then try a small amount of hylomar sealant, it is a soft non hardening sealant used in rolls royce turbines and other stuff, I once used it to seal a under water camera housing I made out of polycarbonate, it allowed the cap end to be removable and reset with just a slight resmearing of sealant,

Sinc
Mitch ret peugeot mech

God no not on a restoration. I'm Glad your using original parts when you can. If you ever plan on showing it that may make a difference. (Concourse judges typically look for things like period correct fasteners, parts, and evidence of disassembly.)

The seals work in compression so as long as they are clean and not dried out and stiff or over compressed they should work fine if you are still worried then any parts store or auto body shop should be able to supply you with weather strip adhesives. I've seen two types those that dry clear or black. (your preference) I would suggest using it sparingly as you wont want a lot of goop to clean up so your buds don't see it.

Good luck with your build.

What kind of car? You'ld be surprised at what's available today if you haven't looked or researched in a while. Year One in Georgia and there are many others.

The car is a 1965 Humber Vogue - sold in the USA as a Singer Vogue.

Making new seals from EPDM actually wouldn't be that difficult. They are a pretty simple shape. That said, the old seals have been treated with glycerin and are in good condition - I'm just concerned about water getting in under them.

Thanks everyone for the advice. I think I'll go the thin smear of trim adhesive - just enough to make me feel like I have done something.