Technical Best exterior gasket material

I made some hard to find flat gaskets out of sheet rubber for my wiper bezels and external hood latches. After a few years, they are cracked and gummy around the edges. I thought it was EDPM that I bought, but beginning to wonder. The rubber has not been exposed to harsh chemicals, gasoline, oil etc. Actually the car has been in a garage.
What type material has worked best for making flay gaskets that weather well for you? Weathering is really my main concern.
TIA

 

I think old inner tube material would hold up pretty good. I have a bit of it if you want a piece to try. Hell, I'll even spring for the stamp!

 

I got a roll of this heavy duty matt that they use on horse stable floors. This makes excellent gasket material. But it is thick..

 

Go to a nearby rubber and seal house. You can buy sheets of neoprene in different thiroughshod. A yard will last a long time.. I keep 1/16 & 1/8 on hand all the time and it holds up well.

Wipe the sheet clean with some thinner or solvent, trace out your pattern on the sheet with a ball point pen. Get in some good light and it will show up kind of reddish. Use a pair of sharp surgical scissors and take your time. You can cut really smooth lines with practice and you can use sand paper to clean up any roughspots.

 

Mopars used a thin white foam type material starting in the 1960s...I sometimes find this material used as packing material. That would be a good one to try.

I just installed a new set of door handles on my Chevy II, they came with the thin rubber gaskets. I did not use them, as I don't recall Chevy ever having used a material like that on those parts. Probably for the reasons that you started this thread....they don't work.

I'd use a paper or plastic material, if I had to use a gasket. Mostly, if there is not something like that available, I use nothing at all.

 

Rubber roofing, used on flat roofs. It sits in the sun all day without breaking down.

Excellent to have a partial roll around the shop, find a local roofer and ask for a drop or end of a roll.

 

My 1965 impala had gaskets under the exterior door handles & the locks ,also the trunk lock...I remember one way that you could tell a repaint is if there was paint on the gaskets..

 

What material were they? It wasn't a soft rubber, was it?

 

Well, I thought the rubber sheet I cut them from was EDPM material, but the gasket poor performance now has me wondering if it really was. I bought the sheet based on EDPM quality for weathering, but it has been disappointing.

 

Ugh! I jut threw away a big s**** of it! Tks for the tip.

 

GM didn’t use paint gaskets under the door handles. But they did under the doors and trunk lock.
Probably more of a gasket than paint protection.

 

I've seen a thin plastic gasket under the locks....I don't know if they're properly reproduced?

 

You could probably use old plastic milk jugs or oil bottles.

 

This doesn't mention what material , but they are available here & numerous other sources. There's a felpro sheet gasket material mentioned often when searching " exterior automotive door handle gaskets". Or "1965 Chevy Impala door handle & lock gaskets".

 

that's an OER part number, which is what I got, and they're soft rubber, quite a bit thicker than they ought to be.

 

I remember bicycle inner tube thin but quite a bit stiffer ...

 

I've seen inner tubes crumble just sitting on a shelf in my shed....

 

In my trade , I would get old gas regulator diaphragms . They were thin stuff , rubber cord between the 2 layers . That stuff will last forever and a day .

 

I wasn't suggesting using inner tube , just using that material as a reference for thickness & feel , something many could relate to . ..

 

McMaster Carr has rubber sheet Material