[Healeys] Ethanol effects on rubber

[Mirek Sharp]

Bob, Absolutely interested!  Thanks for taking an experimental approach to this oft-discussed issue.

Mirek

-----Original Message-----
From: Healeys [mailto:healeys-bounces at autox.team.net] On Behalf Of Bob Spidell
Sent: June-22-18 3:19 PM
To: Healeys
Subject: [Healeys] Ethanol effects on rubber

Just when you thought you'd heard the last on this ...

Having bragged about my scientific creds, I decided I needed to do some 'scientific' experimenting.  I bought a new HD8 diaphragm jet from Tom's and put it in a jar submerged in denatured alcohol.  If you're not familiar with denatured alcohol, it's ethanol--i.e. booze--with one or more denaturing chemicals to make it unpalatable to drink.  When I first did this thought experiment, I thought DA was mostly ethanol, but the quart I bought at a hardware store claims to be 45-50% ethanol and the remainder methanol (and probably some water as both alcohols are hygroscopic).  Though this mixture doesn't represent the 10% or so of ethanol in gasahol, IIRC from my college chemistry and lab technician days that methanol is even more corrosive than ethanol.  So, this should be a good test of the rubber part of the jet's resistance to these solvents (and the brass part too, I suppose).  I put new jets in my BJ8's HD8s two years/12K miles ago, and should have done this then in case the results were scary, but maybe this will tell us something. I'll check the jet periodically for degradation and, if anybody's interested let you know.

Cheers,

Bob