Return-Path: Received: from smtp810.mail.sc5.yahoo.com ([66.163.170.80] verified) by logan.com (CommuniGate Pro SMTP 4.2b2) with SMTP id 3181537 for flyrotary@lancaironline.net; Tue, 20 Apr 2004 18:47:10 -0400 Received: from unknown (HELO Davidscmptr) (dcarter11@sbcglobal.net@216.63.105.110 with login) by smtp810.mail.sc5.yahoo.com with SMTP; 20 Apr 2004 22:36:57 -0000 Message-ID: <005601c42727$f9bc6de0$6401a8c0@Davidscmptr> Reply-To: "David Carter" From: "David Carter" To: "Rotary motors in aircraft" References: Subject: Galvanic action [was:Tap water? (was: water coolant percentages) Date: Tue, 20 Apr 2004 17:36:51 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 Interesting about the galvanic action. I'm on my 3rd radiator in my 1993 Ford Escort. It has the rubber mounting pads top and bottom and rubber hoses - but also has 2 metal tubes from automatic trans that connect to one side of radiator with metal banjo fittings and copper washers - that's a metalic connection to auto trans and thus to the engine. Maybe that is why my the radiator leaks periodically. If we use steel braided hoses between our A/C cores and 13B engine, that will probably also provide an electrical connection. Maybe a "small" reason for using rubber hoses covered by FireSleeve? David ----- Original Message ----- From: "Bill Dube" To: "Rotary motors in aircraft" Sent: Tuesday, April 20, 2004 3:17 PM Subject: [FlyRotary] Tap water? (was: water coolant percentages) > At 08:23 AM 4/20/2004 -0400, you wrote: > > Tommy/John, > > >>> Galvanic action << > The radiator is very often a different metal than the engine block (or other major components wetted by the coolant.) Because of galvanic action, it is very important that the radiator be electrically isolated from the chassis. Otherwise, the two metals will form a battery and current will flow, plating one component with metal from the other. > > You will notice that the radiator in your car is mounted using rubber grommets or plastic parts. It is electrically isolated from the frame. Often, folks will discard the rubber grommets when they R&R the radiator. This happens a lot in body shops. If you electrically connect the radiator to the frame in your car, it will spring a leak in about a year. > > It is wise to rubber mount the radiator in your airplane.