I switched to copper somewhere in that process, but don't remember when. I re--tooled the 17 molds in 82, and it's logical that I made the switch then. You sould be able to look INSIDE the pipe and tell- the copper will be green, the aluminum bright since it's anodized. Use a flashlite. jerry ----- Original Message ----- From: "Michael Ray Wisely" <michaelraywisely@earthlink.net> To: <montgomery_boats@mailman.xmission.com> Sent: Saturday, March 17, 2012 10:46 PM Subject: Re: M_Boats: Cockpit Drainage on 1984 M 17 Hi Jerry, Dave S. and All, I saw the concern about the 81 Cockpit drain pipe. My M 17 (84 model) has the dual underwater drains with hoses connected to dual cockpit drain ports at the port and starboard aft corners of the cockpit. I have had it in the SF bay (Salt) for the past two years and have been worried about them. Just took it out and have concerns. Jerry, or anyone else who might know for sure: We're all of these type made with aluminum pipes or are there some that were made of fiberglass tube or some other piping that I wouldn't have to worry about? I, of course, am too big to squeeze in and don't know anyone that I can trust, who fits, to tell me what the thru hull material is made of. Any advise would be appreciated Jerry, et al. Would rather not try to punch a hole in it to test until I know what the material most likely is, and I have a plan to repair. And, how would you repair it if it was leaking? Not sure what material to put in place if it is Aluminum. Thanks, Michael R. Wisely #384 Molly M. -- I am using the free version of SPAMfighter. We are a community of 7 million users fighting spam. SPAMfighter has removed 6309 of my spam emails to date. Get the free SPAMfighter here: http://www.spamfighter.com/len The Professional version does not have this message