I am in the process of replacing the cockpit drain hoses and thru-hulls and adding valves on my '76 R33. If I were not increasing the diameter of the thru-hulls, I would not replace them and would instead thread on a valve since the thru-hulls are bronze and good condition. I'm tempted to go that route, but have already bought the through-bolt style sea cocks and keep telling myself the additional 0.25" diameter is 44% more area. So assuming you can get matching threads on the valve and the thru-hulls are not corroded, it's a much simpler task to keep them.
06-24-2011 12:21 AM
Although this is a fairly old thread, I thought I'd respond anyway. My R33 has what you speak of - Sea water comes in the thru hull and has "T" then bronze valve before going on to cool the engine. The other part of the "T" has a bronze valve before going on to the sink. This system allows me to have one thru hull for both and I can shut off each independently. When the engine is off I close it's valve and if I think about it - when motoring for long distances - I will shut off the sea water to the sink - just an extra safety thing. You could shut off the sink valve every time you start the engine if you wanted.
For my two bilge pump - one switched - one auto - I use two thru hulls and two hoses.
01-29-2011 09:08 PM
I think your surveyor was probably commenting on the gate valves. They were commonly used on many boats decades ago, and are a poor choise. Usually made from brass instead of marine quality bronze they were a big source of problems.I have often replaced these with either Bronze (Groco) or Marelon (Forespar) ball valves. Check out Wests catalog for good advise re: thread types. NPS does not mate with NPT(pipe) thread properly. Thru hulls are NPS, and may not neccesarily need to be replaced.
Btw: I would NOT combine any other fitting to the raw water intake. If your engine cooling pump sucked air the result could be most regretable
01-09-2011 12:02 PM
Ranger 33 Through Hull Replacement
We are the proud new owners of a Ranger 33. One of the things the surveyor recommended was replacing all of the old gate valves on the through hulls. I assume that the best thing to do here is replace the through hull and seacock?
I also read somewhere that combining through hulls for multiple functions is a good idea to reduce the number (i.e. combining the sea water intake for the engine with the sea water intake for the sink). Has anyone done this on the Ranger, or is this a bad idea?