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Through-hull question
It is accepted practice to through-bolt seacocks even with a fiberglass
hull. there should be a backing plate wide enough to spread the load. -- Dennis Gibbons S/V Dark Lady CN35-207 email: dennis dash gibbons at worldnet dot att dot net "Trent D. Sanders" wrote in message om... We replaced all the through-hulls on my Islander 29 with new bronze through-hulls and bronze/stainless ball valves. The threads on the through-hulls were straight threads, while the threads on the ball valves were tapered [pipe] threads. As a consequence the ball valves only tightened down on the through-hulls by about 2 "turns". The yardman that did the job said that was the "accepted practice" and not to worry about it. But,,,, in this month's issue of Good Old Boat's newsletter supplement there's this,,, "You must use straight threads on both the valve and through-hull, or tapered on both. Mixing tapered and straight threads is the worst thing you can do, and sadly it is [or was] common". So, my question is,,,, does anyone know where to obtain bronze/stainless ball valves with straight threads? Easier to replace the ball valves rather than the through-hulls. I'd use proper seacocks but they require bolting to the hull which would be difficult with a fiberglass hull. Thanking you in advance, Trent Sanders S/V Cimba Marina Del Rey Southern California |
Through-hull question
Hummmm. It seems that many production boat manufacturers
are doing it wrong then. My old C&C didn't have any of the seacocks through-bolted. On my current boat the seacock has a flange which does secure the thru-hull, but there are no provision for bolts. Doug s/v Callista "98stratus" wrote in message ... Wrong... if you use a proper seacock, throw the nut from the through hull away. The seacock should be through bolted, but mose people seem to screw it to the backing plate. Which is better than nothing. Also throw away those ball vales, they are not designed for this task and. Yes you are correct you only have 2 or 3 threads seperating you from a sinking! Pierre "doug dotson" wrote in message ... I think you have answered your own question. To the best of my knowledge ball valves are not acceptable for seacocks. Not sure why. That may be why thru-hulls and seacocks use straight threads. So ball valves won't fit. I've never had a seacock bolted to the hull. Normally the thru-hull is bedded and secured with the retaining ring and the seacock is just threaded on. Even though the seacock has a flange that will accept bolts, the flange has always just floated. Doug s/v Callista "Trent D. Sanders" wrote in message om... We replaced all the through-hulls on my Islander 29 with new bronze through-hulls and bronze/stainless ball valves. The threads on the through-hulls were straight threads, while the threads on the ball valves were tapered [pipe] threads. As a consequence the ball valves only tightened down on the through-hulls by about 2 "turns". The yardman that did the job said that was the "accepted practice" and not to worry about it. But,,,, in this month's issue of Good Old Boat's newsletter supplement there's this,,, "You must use straight threads on both the valve and through-hull, or tapered on both. Mixing tapered and straight threads is the worst thing you can do, and sadly it is [or was] common". So, my question is,,,, does anyone know where to obtain bronze/stainless ball valves with straight threads? Easier to replace the ball valves rather than the through-hulls. I'd use proper seacocks but they require bolting to the hull which would be difficult with a fiberglass hull. Thanking you in advance, Trent Sanders S/V Cimba Marina Del Rey Southern California |
Through-hull question
Hummmm. It seems that many production boat manufacturers
are doing it wrong then. My old C&C didn't have any of the seacocks through-bolted. On my current boat the seacock has a flange which does secure the thru-hull, but there are no provision for bolts. Doug s/v Callista "98stratus" wrote in message ... Wrong... if you use a proper seacock, throw the nut from the through hull away. The seacock should be through bolted, but mose people seem to screw it to the backing plate. Which is better than nothing. Also throw away those ball vales, they are not designed for this task and. Yes you are correct you only have 2 or 3 threads seperating you from a sinking! Pierre "doug dotson" wrote in message ... I think you have answered your own question. To the best of my knowledge ball valves are not acceptable for seacocks. Not sure why. That may be why thru-hulls and seacocks use straight threads. So ball valves won't fit. I've never had a seacock bolted to the hull. Normally the thru-hull is bedded and secured with the retaining ring and the seacock is just threaded on. Even though the seacock has a flange that will accept bolts, the flange has always just floated. Doug s/v Callista "Trent D. Sanders" wrote in message om... We replaced all the through-hulls on my Islander 29 with new bronze through-hulls and bronze/stainless ball valves. The threads on the through-hulls were straight threads, while the threads on the ball valves were tapered [pipe] threads. As a consequence the ball valves only tightened down on the through-hulls by about 2 "turns". The yardman that did the job said that was the "accepted practice" and not to worry about it. But,,,, in this month's issue of Good Old Boat's newsletter supplement there's this,,, "You must use straight threads on both the valve and through-hull, or tapered on both. Mixing tapered and straight threads is the worst thing you can do, and sadly it is [or was] common". So, my question is,,,, does anyone know where to obtain bronze/stainless ball valves with straight threads? Easier to replace the ball valves rather than the through-hulls. I'd use proper seacocks but they require bolting to the hull which would be difficult with a fiberglass hull. Thanking you in advance, Trent Sanders S/V Cimba Marina Del Rey Southern California |
Through-hull question
Not surprising. A proper flanged and bolted bronze seacock cost about 4
times as much as a throughhull and ball valve. I compromised with flanged and bolted Marelon. doug dotson wrote: Hummmm. It seems that many production boat manufacturers are doing it wrong then. My old C&C didn't have any of the seacocks through-bolted. On my current boat the seacock has a flange which does secure the thru-hull, but there are no provision for bolts. Doug s/v Callista "98stratus" wrote in message ... Wrong... if you use a proper seacock, throw the nut from the through hull away. The seacock should be through bolted, but mose people seem to screw it to the backing plate. Which is better than nothing. Also throw away those ball vales, they are not designed for this task and. Yes you are correct you only have 2 or 3 threads seperating you from a sinking! Pierre "doug dotson" wrote in message ... I think you have answered your own question. To the best of my knowledge ball valves are not acceptable for seacocks. Not sure why. That may be why thru-hulls and seacocks use straight threads. So ball valves won't fit. I've never had a seacock bolted to the hull. Normally the thru-hull is bedded and secured with the retaining ring and the seacock is just threaded on. Even though the seacock has a flange that will accept bolts, the flange has always just floated. Doug s/v Callista "Trent D. Sanders" wrote in message e.com... We replaced all the through-hulls on my Islander 29 with new bronze through-hulls and bronze/stainless ball valves. The threads on the through-hulls were straight threads, while the threads on the ball valves were tapered [pipe] threads. As a consequence the ball valves only tightened down on the through-hulls by about 2 "turns". The yardman that did the job said that was the "accepted practice" and not to worry about it. But,,,, in this month's issue of Good Old Boat's newsletter supplement there's this,,, "You must use straight threads on both the valve and through-hull, or tapered on both. Mixing tapered and straight threads is the worst thing you can do, and sadly it is [or was] common". So, my question is,,,, does anyone know where to obtain bronze/stainless ball valves with straight threads? Easier to replace the ball valves rather than the through-hulls. I'd use proper seacocks but they require bolting to the hull which would be difficult with a fiberglass hull. Thanking you in advance, Trent Sanders S/V Cimba Marina Del Rey Southern California -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Through-hull question
Not surprising. A proper flanged and bolted bronze seacock cost about 4
times as much as a throughhull and ball valve. I compromised with flanged and bolted Marelon. doug dotson wrote: Hummmm. It seems that many production boat manufacturers are doing it wrong then. My old C&C didn't have any of the seacocks through-bolted. On my current boat the seacock has a flange which does secure the thru-hull, but there are no provision for bolts. Doug s/v Callista "98stratus" wrote in message ... Wrong... if you use a proper seacock, throw the nut from the through hull away. The seacock should be through bolted, but mose people seem to screw it to the backing plate. Which is better than nothing. Also throw away those ball vales, they are not designed for this task and. Yes you are correct you only have 2 or 3 threads seperating you from a sinking! Pierre "doug dotson" wrote in message ... I think you have answered your own question. To the best of my knowledge ball valves are not acceptable for seacocks. Not sure why. That may be why thru-hulls and seacocks use straight threads. So ball valves won't fit. I've never had a seacock bolted to the hull. Normally the thru-hull is bedded and secured with the retaining ring and the seacock is just threaded on. Even though the seacock has a flange that will accept bolts, the flange has always just floated. Doug s/v Callista "Trent D. Sanders" wrote in message e.com... We replaced all the through-hulls on my Islander 29 with new bronze through-hulls and bronze/stainless ball valves. The threads on the through-hulls were straight threads, while the threads on the ball valves were tapered [pipe] threads. As a consequence the ball valves only tightened down on the through-hulls by about 2 "turns". The yardman that did the job said that was the "accepted practice" and not to worry about it. But,,,, in this month's issue of Good Old Boat's newsletter supplement there's this,,, "You must use straight threads on both the valve and through-hull, or tapered on both. Mixing tapered and straight threads is the worst thing you can do, and sadly it is [or was] common". So, my question is,,,, does anyone know where to obtain bronze/stainless ball valves with straight threads? Easier to replace the ball valves rather than the through-hulls. I'd use proper seacocks but they require bolting to the hull which would be difficult with a fiberglass hull. Thanking you in advance, Trent Sanders S/V Cimba Marina Del Rey Southern California -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Through-hull question
The reason often given as to why ball valves are not "acceptable" on thru-hulls
is that they lack the support that seacocks have. That support MIGHT be needed to close them in an emergency and could possible break off (with disasterous results unless you had some tapered wood plugs handy). Yet many boats come equipped with properly functioning ball valves. I think the key here is make sure your ball valves continue to properly function by actuating them once a month or so and lubricating the top and bottom of the ball at least annually. If they are working properly, they are probably safe enough. Certainly safer than a seacock that has not been maintained.... |
Through-hull question
The reason often given as to why ball valves are not "acceptable" on thru-hulls
is that they lack the support that seacocks have. That support MIGHT be needed to close them in an emergency and could possible break off (with disasterous results unless you had some tapered wood plugs handy). Yet many boats come equipped with properly functioning ball valves. I think the key here is make sure your ball valves continue to properly function by actuating them once a month or so and lubricating the top and bottom of the ball at least annually. If they are working properly, they are probably safe enough. Certainly safer than a seacock that has not been maintained.... |
Through-hull question
I don't trust plastic below the waterline. Marelon is
plenty strong but bronze is stronger. I have to install a few more thru-hulls this spring. I guess I'll have to do some thinking about it. Doug s/v Callista "Glenn Ashmore" wrote in message news:vvkDb.4930$JD6.3668@lakeread04... Not surprising. A proper flanged and bolted bronze seacock cost about 4 times as much as a throughhull and ball valve. I compromised with flanged and bolted Marelon. doug dotson wrote: Hummmm. It seems that many production boat manufacturers are doing it wrong then. My old C&C didn't have any of the seacocks through-bolted. On my current boat the seacock has a flange which does secure the thru-hull, but there are no provision for bolts. Doug s/v Callista "98stratus" wrote in message ... Wrong... if you use a proper seacock, throw the nut from the through hull away. The seacock should be through bolted, but mose people seem to screw it to the backing plate. Which is better than nothing. Also throw away those ball vales, they are not designed for this task and. Yes you are correct you only have 2 or 3 threads seperating you from a sinking! Pierre "doug dotson" wrote in message ... I think you have answered your own question. To the best of my knowledge ball valves are not acceptable for seacocks. Not sure why. That may be why thru-hulls and seacocks use straight threads. So ball valves won't fit. I've never had a seacock bolted to the hull. Normally the thru-hull is bedded and secured with the retaining ring and the seacock is just threaded on. Even though the seacock has a flange that will accept bolts, the flange has always just floated. Doug s/v Callista "Trent D. Sanders" wrote in message e.com... We replaced all the through-hulls on my Islander 29 with new bronze through-hulls and bronze/stainless ball valves. The threads on the through-hulls were straight threads, while the threads on the ball valves were tapered [pipe] threads. As a consequence the ball valves only tightened down on the through-hulls by about 2 "turns". The yardman that did the job said that was the "accepted practice" and not to worry about it. But,,,, in this month's issue of Good Old Boat's newsletter supplement there's this,,, "You must use straight threads on both the valve and through-hull, or tapered on both. Mixing tapered and straight threads is the worst thing you can do, and sadly it is [or was] common". So, my question is,,,, does anyone know where to obtain bronze/stainless ball valves with straight threads? Easier to replace the ball valves rather than the through-hulls. I'd use proper seacocks but they require bolting to the hull which would be difficult with a fiberglass hull. Thanking you in advance, Trent Sanders S/V Cimba Marina Del Rey Southern California -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Through-hull question
I don't trust plastic below the waterline. Marelon is
plenty strong but bronze is stronger. I have to install a few more thru-hulls this spring. I guess I'll have to do some thinking about it. Doug s/v Callista "Glenn Ashmore" wrote in message news:vvkDb.4930$JD6.3668@lakeread04... Not surprising. A proper flanged and bolted bronze seacock cost about 4 times as much as a throughhull and ball valve. I compromised with flanged and bolted Marelon. doug dotson wrote: Hummmm. It seems that many production boat manufacturers are doing it wrong then. My old C&C didn't have any of the seacocks through-bolted. On my current boat the seacock has a flange which does secure the thru-hull, but there are no provision for bolts. Doug s/v Callista "98stratus" wrote in message ... Wrong... if you use a proper seacock, throw the nut from the through hull away. The seacock should be through bolted, but mose people seem to screw it to the backing plate. Which is better than nothing. Also throw away those ball vales, they are not designed for this task and. Yes you are correct you only have 2 or 3 threads seperating you from a sinking! Pierre "doug dotson" wrote in message ... I think you have answered your own question. To the best of my knowledge ball valves are not acceptable for seacocks. Not sure why. That may be why thru-hulls and seacocks use straight threads. So ball valves won't fit. I've never had a seacock bolted to the hull. Normally the thru-hull is bedded and secured with the retaining ring and the seacock is just threaded on. Even though the seacock has a flange that will accept bolts, the flange has always just floated. Doug s/v Callista "Trent D. Sanders" wrote in message e.com... We replaced all the through-hulls on my Islander 29 with new bronze through-hulls and bronze/stainless ball valves. The threads on the through-hulls were straight threads, while the threads on the ball valves were tapered [pipe] threads. As a consequence the ball valves only tightened down on the through-hulls by about 2 "turns". The yardman that did the job said that was the "accepted practice" and not to worry about it. But,,,, in this month's issue of Good Old Boat's newsletter supplement there's this,,, "You must use straight threads on both the valve and through-hull, or tapered on both. Mixing tapered and straight threads is the worst thing you can do, and sadly it is [or was] common". So, my question is,,,, does anyone know where to obtain bronze/stainless ball valves with straight threads? Easier to replace the ball valves rather than the through-hulls. I'd use proper seacocks but they require bolting to the hull which would be difficult with a fiberglass hull. Thanking you in advance, Trent Sanders S/V Cimba Marina Del Rey Southern California -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
Through-hull question
Doug Dotson wrote: I don't trust plastic below the waterline. Marelon is plenty strong but bronze is stronger. I have to install a few more thru-hulls this spring. I guess I'll have to do some thinking about it. I had the same worry before I decided so I tried (as my compulsive engineer personality requires) to analyze the threat. Corrosion is not a problem. The main threats of marelon vs bronze are breakage because of the lower ultimate strength and dimensional stability. Dimensional stability results in sticking so routine exercising the valve and lubrication are definitely in order. That is a good idea for bronze also because chrome on bronze balls can flake and jam and stainless balls can suffer crevasse corrosion between the seals. That leaves the strength to be tested. I see 3 potential forces acting on a flange mounted throughhull. The water pressure from outside for which the flanges are far over designed, the bending force of the hose and fittings but the fittings are much weaker than the throughuull and potential impacts. Side impacts would be the big worry. I tried to visualize what would cause a significant side impact on a throughhull, probably in a knock down or roll over and came up with a battery breaking loose, an anchor stowed loose in the bilge. So I found an old used Forespar 1 1/2" seacock on ebay, mounted it on a piece of 1/4" steel plate and whacked it on the side with a 5 lb sledge. First blow had no effect. Second blow produced a small crack about 1" long leading from the valve stem. Third blow broke a bolt flange and lengthened the crack some but it was still well attached to the throughhull. I have beaten enough bronze castings to pieces to fit in my crucible furnace that I don't believe a bronze throughhull would have held up but a little better. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
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