Never seen an NPS in bronze.
And how can you say "just plastic"? Have you seen the price of these things? I'm led to believe they are hand made by a temple of vestal virgins at those prices
.
Through-Hull to Ball Valve Joint
- Thread starter dkinzer
- Start date
And how can you say "just plastic"? Have you seen the price of these things? I'm led to believe they are hand made by a temple of vestal virgins at those prices
.
Its simple: don't use 'ball valves' or 'gate valves' of any sort. You need a seacock that, by definition, is engineered to mate with the NPS threads of your through hull fitting. Seacocks are made of the proper marine metals or plastics and have balls or tapered plugs as the moving, sealing part. They are expensive and are available from reputable manufacturers such as Apollo, Buck Algonquin, Perko, Groco, and Marelon. Accept no substitute.
Note that thru hull fittings, valves, etc. with BSPP threads are available in the USA; you can order them on the Groco website. These components all have the same threads; therefore, mis matched thread problem is eliminated. Not as good as dedicated seacock; however, I am not going to spend several thousand dollars to modify my grid / pan and build up the interior hull surfaces to accommodate seacocks.
Just redid all my thru hulls - used Groco Flanged seacocks all around. Excellent product! Also redesigned a couple, removed 3 so instead of having 8 thru hulls, some in very strange places, I now have 5 thru hulls, all in very logical and easily accessed locations...Its simple: don't use 'ball valves' or 'gate valves' of any sort. You need a seacock that, by definition, is engineered to mate with the NPS threads of your through hull fitting. Seacocks are made of the proper marine metals or plastics and have balls or tapered plugs as the moving, sealing part. They are expensive and are available from reputable manufacturers such as Apollo, Buck Algonquin, Perko, Groco, and Marelon. Accept no substitute.
dj
I went thu hull the same issues when i bought all my stuff from Groco
Yeah it cost more to do it the right way but your boat your choice
Yeah it cost more to do it the right way but your boat your choice
Thanks sailme88 and CYQK. Yeah the seacock is entirely disassembled (see photo). I cannot find a 1/2-inch seacock to replace the original Groco SV-500, even a used one. I will also experiment with rejuvenating the withered rubber tapered cone core of the seacock and one day I will drill out the entire thruhull and replace with a 1 inch (tedious, because it is embedded in the fibreglass hull). (Others will join in the safety caveats about thuhulls and seacocks - I am also aware that 1/2 inch and 3/4 inch bronze seacocks fail the ABYC 500 lbs test but this is an enclosed area where such a force is very unlikely).
Attachments
Apparently the usual problem of vintage Groco rubber core seacocks is that the rubber expands and operation becomes stiff over time. In this case it is abraided, withered and stiff. I cannot compress the rubber core enough with the thumbscrew to achieve a seal. Has anyone heard of the idea of adding a copper or bronze penny to the bronze compression disk that the thumbsrew operates against? Has anyone heard of rejuvenating this type of rubber by soaking it in isopropyl alcohol and methyl salicate (oil of wintergreen)?
I would look for a bronze washer, not a penny. That's if it really is going to work.
I would be VERY skeptical of the rejuvenating formula you've posted. But I've not tried it. My polymer side is saying not a likely good option for a critical component like this.
dj