it's a good point - I just looked and it's not that different from water. But, I've seen fuel systems that ran on pure methanol corroded pretty quickly if they weren't cleaned out after a run. I guess the corrosion is enhanced in methanol by effects on the surface layer of metals like aluminum and magnesium, that depend on a surface layer to halt corrosion. -- Lee K. Gleason N5ZMR Control-G Consultants lee.gleason at comcast.net -----Original Message----- From: Hans Vlems Sent: Saturday, May 17, 2014 3:31 PM To: hecnet at Update.UU.SE Subject: Re: [HECnet] TK50 issues Lee, have you looked up the pKa for methanol? Verzonden vanaf mijn BlackBerry 10-smartphone. Origineel bericht Van: Lee Gleason Verzonden: zaterdag 17 mei 2014 22:17 Aan: hecnet at Update.UU.SE Beantwoorden: hecnet at Update.UU.SE Onderwerp: Re: [HECnet] TK50 issues Methanol would do as well but is more poisonous. Careful with methanol - it's a more potent solvent in general than ethanol or isopropanol. Lots of rubber and plastic compounds are attacked by methanol. Additionally, the H in the OH group isn't held onto as tightly as in the other organic OH compounds, so methanol is corrosive to metal. It's also a middlin' good oxidizer for some metals. -- Lee K. Gleason N5ZMR Control-G Consultants lee.gleason at comcast.net