Date: Tue, 19 May 1998 09:34:57 -0800 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: Re: COZY: Question O-320-E2A?? >The engine mount extrusions should be stainless steel, not aluminum. They are >standard on the COSY CLASSIC and should be available from Wicks. I seem to remember a recent reference here (or possibly on another newsgroup) to Stainless Steel in epoxy, that mentioned corrosion of the stainless. This referred to embedded bolts, and suggested that the bolts were destined to eventually break off at the junction between the bolt and the epoxy surface. I personally never would have imagined that this could be a problem. I am planning on converting my stock aluminum extrusions for hanging an O-320, and the stainless replacement (or possibly steel) certainly sounds like a nice solution to the problem, but I would like to hear more details about any possible problem with the materials. Steel would seem like a logical choice, since it is (depending on the alloys, of course) considerably stronger than the stainless, and it would certainly be compatible with the steel motor mount. Comments? Howard Rogers --Howard Rogers, 415-926-4052 hrogers@slac.stanford.edu Date: Tue, 19 May 1998 11:55:44 -0500 From: Tom Brusehaver Subject: Re: COZY: Question O-320-E2A?? >I seem to remember a recent reference here (or possibly on another >newsgroup) to Stainless Steel in epoxy, that mentioned corrosion of the >stainless. This referred to embedded bolts, and suggested that the bolts >were destined to eventually break off at the junction between the bolt and >the epoxy surface. I personally never would have imagined that this could >be a problem. I am planning on converting my stock aluminum extrusions for >hanging an O-320, and the stainless replacement (or possibly steel) >certainly sounds like a nice solution to the problem, but I would like to >hear more details about any possible problem with the materials. Steel >would seem like a logical choice, since it is (depending on the alloys, of >course) considerably stronger than the stainless, and it would certainly be >compatible with the steel motor mount. Comments? I remember a conversation in relation to boats rather than airplanes, about stainless steel. The properties that make stainless corrosion resistant are valid when the stainless steel is exposed to air (oxygen? i don't remember). If the stainless is submerged constantly, it will corrode like any steel. If the stainless is embedded in epoxy, I would imagine the same thing happening. Any moisture in the joint area would cause the stainless to corrode. From: cdenk@ix.netcom.com Date: Tue, 19 May 1998 14:54:23 -0500 (CDT) Subject: Re: COZY: Question O-320-E2A?? I don't know, I can't see any corrosion on my stainless angles after 4.5 years. One could always go to 4130 steel, and coat or plate for protection. If the comment is for marine applications, it might be aimed at continuous immersion in salt water.