WE have an '88 H285. She has 4 gate valves (Under each sink, head inlet and for the engine cooling water). They look like brass (shiny metal vs the dull look of bronze). I want to change them over to ball valves but hate to waste the money by buying them at a "marine" store. Home depot has the same thing in brass for 1/3 the $. Question is, are the thru-hull threads made to accept only "marine"-type ball valves? I read somewhere that you have to be careful that the threads are not tapered. Has anyone made this changeover? Anything to watch out for? Should I use teflon tape to help seal the threads????
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Brass is a generic term
Rick Not all brass is the same - there are a number of variations depending upon the design use and the material you will find at the big box stores is the most inferior grade available. A member of my family manufacturers brass and sells to them and their specs are not suitable for marine use, even in fresh water. Unless you know the difference, you'd be much safer getting the valves at a store which sells for marine applications, either brass or bronze depending on your concern for corrosion. Your thru-hulls are likely tapered and should be matched in both taper and thread size to the new valves. If you want to use anything on the threads, I'm told to use plumbers putty rather than tape. Don
Rick Not all brass is the same - there are a number of variations depending upon the design use and the material you will find at the big box stores is the most inferior grade available. A member of my family manufacturers brass and sells to them and their specs are not suitable for marine use, even in fresh water. Unless you know the difference, you'd be much safer getting the valves at a store which sells for marine applications, either brass or bronze depending on your concern for corrosion. Your thru-hulls are likely tapered and should be matched in both taper and thread size to the new valves. If you want to use anything on the threads, I'm told to use plumbers putty rather than tape. Don
Use seacocks not ball valves
You can check out the full explanations in the West Marine and other catalogs. Most bronze ball valves are not recommended for use as a seacock, attached to your thru hulls. Marelon ball valves are available and should stand up to saltwater and electrolysis. The threads on all thru hulls are straight (NPS)and not tapered (NPT). The ball valves have tapered threads and will not form a strong seal right where you need it most.
You can check out the full explanations in the West Marine and other catalogs. Most bronze ball valves are not recommended for use as a seacock, attached to your thru hulls. Marelon ball valves are available and should stand up to saltwater and electrolysis. The threads on all thru hulls are straight (NPS)and not tapered (NPT). The ball valves have tapered threads and will not form a strong seal right where you need it most.
Not Plumber's Putty
You want Teflon tape or Pipe Dope (Thread Sealing Compound. Plumbers putty is not used for threads but is a Putty like Play Dough. When I do mine in the Spring I will be useing Both Teflon Tape then followed with a small coating of Pipe Dope. Cliff H 28.5 "Red Dog" Sailor/Plumber
You want Teflon tape or Pipe Dope (Thread Sealing Compound. Plumbers putty is not used for threads but is a Putty like Play Dough. When I do mine in the Spring I will be useing Both Teflon Tape then followed with a small coating of Pipe Dope. Cliff H 28.5 "Red Dog" Sailor/Plumber
Plumbers Grease
Just a note . .I always make sure to dab some plumbers grease on the inside when using marelon valves. It keeps the valve working nice and easy and lasts several seasons before another lube job is necessary. Fred Miller S/V M2
Just a note . .I always make sure to dab some plumbers grease on the inside when using marelon valves. It keeps the valve working nice and easy and lasts several seasons before another lube job is necessary. Fred Miller S/V M2
No Metal Valve Lasts Forever
While some metal valves may last longer than others there is no metal valve that will last forever. All metal is subject to electrolysis, some more so than others, and it's the electrolysis that is a real concern. Don't count on looking at the outside of the valve and moving the handle to assume that your metal valve is "okay". Examine the inside and the threads before making the determination. Unfortunately, it's really difficult to examine the inside of the small valves on our boats to that makes proper maintenance inspection nearly impossible. And besides, to examine the treads one would basically have to remove the valve. That's a lot of work. I told a story about my friends valve almost sinking his C&C 36 on an earlier post (to a different thread), describing how his valve looked reasonably fine on the outside but breaking off without anybody knowing about it and nearly sinking the boat. To each his own, but personally I'd rather opt for any alleged downsides to Marlon valves as opposed to dealing with metal valves.
While some metal valves may last longer than others there is no metal valve that will last forever. All metal is subject to electrolysis, some more so than others, and it's the electrolysis that is a real concern. Don't count on looking at the outside of the valve and moving the handle to assume that your metal valve is "okay". Examine the inside and the threads before making the determination. Unfortunately, it's really difficult to examine the inside of the small valves on our boats to that makes proper maintenance inspection nearly impossible. And besides, to examine the treads one would basically have to remove the valve. That's a lot of work. I told a story about my friends valve almost sinking his C&C 36 on an earlier post (to a different thread), describing how his valve looked reasonably fine on the outside but breaking off without anybody knowing about it and nearly sinking the boat. To each his own, but personally I'd rather opt for any alleged downsides to Marlon valves as opposed to dealing with metal valves.
How much will you save over the life of the valve?
Use bronze, not brass. Should have yellow tags, brass I think has green or blue. Brass is OK for fuel and natural gas. Bronze is best for thru-hulls and ball valves.
Use bronze, not brass. Should have yellow tags, brass I think has green or blue. Brass is OK for fuel and natural gas. Bronze is best for thru-hulls and ball valves.
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