Bronze sea cock servicing

One thing I have always used is genuine cast bronze sea cocks on any of my own boats,this may not be the lowest cost option but for peace of mind its unbeatable.Service of these is a fairly simple affair,you undo a couple of nuts,remove the center cone,re apply grease and replace the cone and refit the nuts,I normally do this when I slip the boat for an antifoul job every few years.

I used to use what ever grease was to hand,which in my case was normally Shells multi purpose Retinax A,which is a do it all type of grease used on wheel bearings and the like.This I found to work but after a year or so,the sea cock would start to tighten up,then I discoverd Duckhams waterproof grease! I bought a 500mm tub and its lasted decades,it also works over a much long period and I have never had a seized sea cock since changing to Duckhams,that has all been used up now and I have moved to Wynns water proof grease,time will tell how long that lasts?

Removal of the center cone is easy when on the hard but what about when the boat is in the water? not a good idea but when a sea cock starts to drip and a normally dry bilge is wet,what then,slipping just for a sea cock sounds expensive.In my case it also means traveling to Cape Town to use a slip,so its a big job all of a sudden.I finally decided to attempt an In the water Service,removal of the center cone was easy,the rush of incoming sea water was stopped with a rag of towling,it still leaked but not much,I then cleaned the bronze cone and lightly sanded it,applying water proof grease I then refitted it.I then had the idea to try the mandatory wooden taper plug that all boats should carry,mine are tied to each sea cock for ease of finding it in an emergency.

In this case I thought that the lanyard may hinder the plug as I had drilled through the larger end of the taper plug,removal of the lanyard and trying the plug in the sea cock prooved this to be correct and had I left the lanyard in place the plug would have stopped short of full entry and of course the water would have poured in.I now found that in this case the taper of the wooden plug was exactly the same of the sea cock body,we had a perfect match and not a drop of water now entered the boat!

I now started to consider service of all of the boats bronze sea cocks,normally a full days work in my case,this has worked well,I have now done four more and made other dicoveries as I worked.Tapers are not standard,some plugs worked to a point but did allow some entry of water,other plugs were too small in diameter and length and would not have done the job at all.

I am servicing in stages and making a note of what sea cock requires which size of wood taper plug,I also now realize that this should have been done prior to installation of the sea cocks in the first place,not as an after thought as was the case,all lanyards will be fastened to the end of the plug with a stainless steel saddle.

Options to solid bronze? They exist but use them with caution,the old type brass Gate Valve is a firm favorite with some but gate valves can block where the gate enters its internal slot,loo paper or other semi solids will do this.Others are Ball Valves,either brass,stainless or plastics,none of which are service friendly without removal of the plastic pipe that is attatched to it,plus full removal from the boats skin fitting.

Caution,never use brass as a skin fitting or sea cock,it will with time corrode and fall off one day when you try and close or open it.At the end of the day we get what we pay for,just check out the quality machine work in the selection of sea cocks I have.

Roy