Firming up rubber? (was: Cleaning rubber goo)

[Maciej W. Rozycki]

On Wed, 4 May 2016, Swift Griggs wrote:

> > Don?t know the cost either, might be way over the top for a joystick! 
> > Another solution I heard was to wipe with isopropyl alcohol or 
> > goo-be-gone, but common sense tells me it?s
> 
> Heh, there are guys who do their Ph.D on stuff like this (materials 
> science). The main thing I would say (and sorry if it sounds trite) is 
> that you want to make sure you use polar solvents and non-polar solvents 
> (ie.. water or oil based) on the appropriate material. So, if it's an oil 
> based adhesive, use a non-polar solvent like lighter fluid etc.. The 
> problem with this is that (as others have said) it's very tough to know if 
> the solvent will break down the rubber, too. You gotta test it. 

 That's the rule of thumb, but as usually there are exceptions.  For 
example water and cyclohexane are strictly polar and non-polar 
respectively, but ethanol and IPA are a bit of both, owing to their 
molecules' structure (IPA's also highly hygroscopic).  Depending on the 
intended use this may be an advantage or disadvantage, and that of course 
also means you need to research any solvent before use, by either studying 
available data or empirically.

  Maciej