I agree, good point. I was recommending the gelstar dielectric grease to be in the section with the moving rotor containing the magnets. The corrosion would probably then be less of an issue. This set-up would be similiar to mud motors that I was discussing have a rotating shaft with bushings (two companies use bearings and one company uses bronze bushings). The grease in the mud motor (they use a moly type) is pumped in via zircs as a periodic routine maintenance. I don't know if the mud motor bushings are oil lite (powdered bronze mixed with oil under high pressure that will self lubricate) or solid bronze. Delrin would probably be better for the u/w robot. Mike ----- Original Message ----- From: "Peter L. Peres" To: Sent: Thursday, August 02, 2001 10:34 PM Subject: Re: [OT]: Underwater robots > Just keep in mind that most 'supermagnets' need a serious coat of paint > (better epoxy paint) because they are very allergic to water (even vapor) > and contain a lot of environment-unfriendly metals (environment-unfriendly > as in you-unfriendly when you are sloshin around the vehicle in the > water). I have never seen anything rust as fast as a supermagnet. It went > from dull gray surface to at least 1 mm deep rust in 45 minutes after the > paint was accidentally scrapped off (at 80% humidity and 30 degrees C). > > Peter > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.