Unless you guys have some special aluminium alloy then the minute you sand or polish the mast or boom down to bare alloy then that's the minute that oxidation of the surface starts, and that new oxide layer forms an impervious protective layer against further corrosion, chemical anodizing can change the surface colour but the protective layer so formed is not much better than that formed on clean aluminium just left in contact with air, and that passive layer forms very quick. So sand it and coat it, 2 part polyurethane is really good and one part is OK too, seems that's what Wally used and he said it's fine after all this time, pay attention and use the proper tie coat on the clean metal if one is required by the top coat you choose. I simply sanded my whole rig down a few years back, it was never coated with anything and the wet sanding to 320 grit removed most of the excess oxide layer that had formed over time and shortly after it dried (on the same day I mean) I applied some polymer wax polish...still good after 4-5 years and much better than before I did the job but I feel pretty sure it had existed for about 30 years before anyone tried to clean it up...I am pretty sure I was the first and only one to do that to Alianna's rig
Dwight Veinot C&C 35 MKII, Alianna Head of St. Margaret's Bay, NS -----Original Message----- From: cnc-list-boun...@cnc-list.com [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Martin DeYoung Sent: July 10, 2012 8:16 PM To: cnc-list@cnc-list.com Subject: Re: Stus-List Spar Re-finish: Powder Coating vs Anodizing + toe rail I want to piggy back on Alex's question regarding a re-coat over anodizing, in my case the C&C toe rail. Any special prep (beyond sand / prime) to paint over the original anodizing? Any case histories of epic success or failure? Martin Calypso 1972 C&C 43 Seattle -----Original Message----- From: cnc-list-boun...@cnc-list.com [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Alex Giannelia Sent: Tuesday, July 10, 2012 3:52 PM To: cnc-list@cnc-list.com Subject: Stus-List Spar Re-finish: Powder Coating vs Anodizing Hi Wally, Thanks for the great links. You've obviously done a fantastic job inside out. On my side the local anodizing shop maxes out at 12' so no go for my spar. However this begs a question for those metallurgists lurking out there: What do I do about the residual anodizing on the spar before I re-coat? ALEX GIANNELIA Phone (416) 203-9858 Fax (416) 203-9843 Cell (416) 529-0070 email: a...@airsensing.com WEB: www.airsensing.com _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2177 / Virus Database: 2437/5123 - Release Date: 07/10/12 _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com
