Re: [Amel Yacht Owners] Genoa sheet track plugs

James Alton


   That is a good point about not using an acid based Silicone on Aluminum.  I have not used the 737 but will give that one a try thanks for the tip.  I do have long term experience with the Dow Corning 3145 Grey silicone caulking on boats caulking in large windows, deck hardware etc.. This is a Mil-spec non acid based caulking that can be used even for electrical work.  This caulking has higher adhesion and elongation qualities than any other silicones that I am familiar with.  The UV and weathering resistance is the best I have seen in a silicone but this only applies to the Grey (there is also a clear version which is also a bit runny) which colour wise blends in pretty well with the aluminum Genoa tracks.   My bulk supplier has a minimum so when I just need a small amount I normally buy it on Ebay, in fact a small tube arrived just today.

   Thanks Gary for sharing your knowledge base.  I especially like the slider seal that you came up with.  My boat has what may be the original slider that has become hard and the noise that the slider makes in use is almost blood curdling.  (grin)  I really need to get that changed this season!

James Alton
SV Sueno
Maramu #220

On Mar 22, 2019, at 11:15 AM, Gary Silver via Groups.Io <garysilver@...> wrote:

Mike, Eric and all:

This is coming from my background as and A & P (FAA airframe and power plant mechanic).  RTV (room temperature vulcanizing) sealants, aka silicone, comes in two basic curing regimens;  acidic curing (Acetoxy or acetic acid) and natural curing.   The acidic curing is prohibited in aircraft as it is corrosive to aluminum structures (also applicable for aluminum structures on sailboats).  Acidic curing RTV is ok on fiberglass.  When selecting any sealant (RTV or otherwise) it is best to avoid acid curing type.  Dow 737 is a natural cure RTV that I use a lot on aircraft but there are others as well. I usually have to order it online (not hard these days) as it isn't widely available in chandleries or the Home Depot type suppliers. 

Gary S. Silver
s/v Liahona
Amel SM 2000 # 335
Puerto Del Rey Marina, Puerto Rico

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