Winterising/flushing

[Garland Gray]

Gordon,Sorry to lose your base of knowledge. Thanks for all of your advice to the group.I have a 3GM30 (freshwater cooled) with SD20-3 saildrive. To make it easier to winterise (next time) and for an occasional flushing of the raw water, I would like to replace the raw water cock mounted on the saildrive with a 3 way ball cock. Do you (or anyone)know of the availablity of one with the required metric threads(24x2, I believe)? I could insert a standard one in the hose, but that wouldn't be as neat and would allow seawater to remain between it and the saildriveThanks.Garland

 

[Gordon Torresen]

SD petcock

The male thread on the sea water petcock is usually metric. It is so close to NPT that you can take a pipe tap and move the threads slightly and substitute a NPT fitting. A little pipe dope and the job is done. Be careful not to hang too much weight on the fitting or have too long of a nipple. The vibration and the resultant accelerations could fatigue the fitting in the threaded area where it enters the sail drive. You might consider placing your valve in the rubber hose that is presently on the petcock to let the rubber do the wiggling.

 

[Garland Gray]

Gordon,Thanks, I'll probably insert it in the hose, as you suggest.