Posted by Mike Hurley on 18/12/2020 09:55:19:
Fascinating. I'm certainly no chemist but was genuinely surprised by Bob Stevenson's comment "….made of synthetic 'bristles' similar to nylon and this is easiy corrupted by oil" (I'm certainly not disagreeing with his point) but I suppose thinking about it, most of the cheap brushes I use for cleaning do end up useless & grotty very quickly! I had thought most synthetic materials were pretty well oil-proof (as most oil comes in synthetic containers in the first place).
Can any scientific bod clarify this (in laymans terms) just out of interest. regards Mike
Nylon resists most things – oils, water, etc, but it has many an Achilles Heel! For example, although Nylon resists most Alcohols, Propanol and Anti-freeze both cause severe damage.
There are a shower of unknowns in the question. Brushes are made from various materials aimed at an intended purpose. Nylon, Teflon, polypropylene, polyester and natural materials like Horse hair, and palm fibre. These can be used alone or mixed. We don't know what our brushes are made of, but as polyester and polypropylene are considerably cheaper than Nylon, we can guess cheap brushes aren't made from the best bristles available.
I wonder what's in the coolant? Water, Oils, Soluble oils, anti-pressure chlorides, disinfectants (perhaps an alcohol) – goodness knows what, mixed with swarf. We can be sure coolant isn't formulated to be kind to paint brushes.
Cheap brushes are intended to work with domestic paints and varnishes, and in my experience aren't particularly good for that. Semi-disposable. So there's no guarantee how well an ordinary paint brush will cope with workshop liquids. I use mine until they stop working, then bin them.
Only a few elements are inert. Everything else is more-or-less unstable. In the right circumstances Asbestos will burn…
Dave