un-deforming rubber parts

What happens when you open the door? Though at -31C you probably don't want to do that and the rubber will be rock hard anyway...

Time and warmth might let it return to it's orginal shape but how much deformation are we talking about in relation to the size of the weather strip?

In message , Jules Richardson writes

WD40

It just remains in the deformed state (and feels quite solid to the touch, although the rest of the strip is still pliable). I expect it's been subjected to this for years.

Well the strip is probably about 12mm uncompressed (i.e. door open) and squashes to 9-10mm with the door closed - expect in the region where the metal strip on the door interferes, which is "permanently" deformed down to about 5mm.

I've heard of castor oil helping to rejuivenate dried-out rubber, but I don't know if it (or anything else) is any use for something which has been deformed due to compression. It may be that replacement is the only option.

cheers

Jules

If you can get the part out. Cooking it up in hot water for half and hour or so helps.

A good idea providing the rubber is oil-resistant, such as nitrile. If it isn't, the door might will need to be re-sealed.

The oil and solvent in WD will cause the rubber to swell, and it might be enough to return it to its original profile (provided the outside temperature is warm enough). Gentle heat from a hair-drier might help the process, but it will take time and perhaps re-application.

I had a leaking garage roof where the felt had split; applying WD 40 a couple of times a year kept it watertight for some 10 years, until a new neighbour wanted his garage re-felted, and as they were attached we had both done at the same time.

I've heard of some using car brake fluid for the rubber surrounds on speakers to restore flexibility. Not tried it myself, but it's cheap enough to try. The ordinary, not silicone, stuff.

I'm not just a pretty face, you know

Brake fluid contains seal sweller; brush some on.