Death-Rays and Car Interiors

[Raforty]

Disintegrator rays date back in science fiction to 1928 with the publication of the first Buck Rogers novel (he entered comic strips the next year). These death-ray weapons would dis-associate all material objects into their component atoms.

Your Toyota’s not likely to encounter a disintegrator gun attack, but the same damage a hostile spaceman could do in a second is done in slow motion over a period of years. And it’s done by the sun.

The ultraviolet rays do the most damage, attacking the plasticisers in vinyl, plastic and synthetic rubber. Plasticisers are those components of plastics that keep them plastic, that is, flexible. The radiation breaks down longer chain molecules first, then the shorter ones. Once molecular bonds are broken, the substance falls apart. In effect, it becomes brittle, cracks and splits into tinier and tinier pieces.

Ultra-violet can’t get through glass, so although your external rubber seals, plastic bumpers and tyres are out in the open, that protects your upholstery somewhat.

However, infra-red rays heat up everything, inside or out. Making substances hotter releases the volatile elements in plastics that keep them soft and supple – those plasticisers again.

Some substances have sacrificial elements to take the brunt of the sun’s attack. The first car tyres were cream coloured because that was the colour of the natural latex they were made from. These tyres were prone to sunburn, like we are, but unlike our skin pigmentation, once these natural rubber tyres were sunburnt, they couldn’t recover. They became brittle, at first on the outside. A brittle tyre doesn’t last very long in normal use. Later, carbon black was added as a sacrificial element, both to add some structural strength and to protect the natural rubber from the UV rays. When your tyres go brownish, that’s the result of losing some carbon black to UV radiation exposure.

Pigments in (synthetic) rubber seals and in vinyl can protect the underlying substance, but only to a point. Once it’s gone, it has to be replaced. That’s easier said than done.

Your Plastics’ False Friend

You can’t use a popular protectant with a brand name that begins with two –‘A’s, or anything else based on silicon oils. These oils replace the plasticisers, but are worse than useless. The silicon oils are even more volatile and short-lived than the plasticisers. So you have to keep re-applying them at short intervals and keep buying the product. Not a good idea for the health of your vinyl and plastics.

I use ‘303 Protectant’, which is specifically designed to replace plasticisers – with plasticisers. It’s not available everywhere, but I use nothing else.