| Home |
| Search |
| Today's Posts |
|
|
|
#1
|
|||
|
|||
Through-hull question
"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 If you can find a tap of the right size, you could "untaper" the ball valve so it fits correctly. |
|
#2
|
|||
|
|||
|
Through-hull question
|
|
#3
|
|||
|
|||
|
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 |
|
#4
|
|||
|
|||
|
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.... |
|
#7
|
|||
|
|||
|
Through-hull question
On Thu, 18 Dec 2003 01:35:52 GMT, Jere Lull wrote:
wrote: Our gate valves were replaced by "marine" ball cocks 11 years ago. Much later, I found out that the "better" Home Depot ball valves were identical. Yes, those are the ones I've installed. BUT there are more-proper "seacock" versions of the ball valves that bolt to/through the hull that you'll only find at the chandlry. I know, and if I was offshore, I wouldn't consider anything else. In fact, I'd opt for strum boxes, a single seacock with valves to elsewhere, and standpipes when feasible. Too many holes in the hull equals too many potential problems, I think. I changed out our engine intake to one because it's not protected against hard knocks, but the innards are identical to the ball valves: chromed brass or copper ball in a brass body (I forget). Thus, we don't bond our sea cocks. Same here. Don't like the colour pink in a metal G I don't lube our ball valves, but open and close them every time we sail. After 10 seasons' use, none show any problems. Same here. Aren't you in salt, though? R. |
|
#8
|
|||
|
|||
|
Through-hull question
On Thu, 18 Dec 2003 01:35:52 GMT, Jere Lull wrote:
wrote: Our gate valves were replaced by "marine" ball cocks 11 years ago. Much later, I found out that the "better" Home Depot ball valves were identical. Yes, those are the ones I've installed. BUT there are more-proper "seacock" versions of the ball valves that bolt to/through the hull that you'll only find at the chandlry. I know, and if I was offshore, I wouldn't consider anything else. In fact, I'd opt for strum boxes, a single seacock with valves to elsewhere, and standpipes when feasible. Too many holes in the hull equals too many potential problems, I think. I changed out our engine intake to one because it's not protected against hard knocks, but the innards are identical to the ball valves: chromed brass or copper ball in a brass body (I forget). Thus, we don't bond our sea cocks. Same here. Don't like the colour pink in a metal G I don't lube our ball valves, but open and close them every time we sail. After 10 seasons' use, none show any problems. Same here. Aren't you in salt, though? R. |
|
#9
|
|||
|
|||
|
Through-hull question
wrote:
On 15 Dec 2003 16:23:29 GMT, (IamAeolus) wrote: 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.... Well, I replaced gate valves with ball cocks from Home Depot here in the Great Lakes, where we can get away with that sort of thing. I check them and keep them moving freely in and out of the water (we are on the hard 5 1/2 months out of 12 in Toronto) but all of them have properly sized plugs tied to their bases. Wouldn't leave the dock without 'em. Our gate valves were replaced by "marine" ball cocks 11 years ago. Much later, I found out that the "better" Home Depot ball valves were identical. BUT there are more-proper "seacock" versions of the ball valves that bolt to/through the hull that you'll only find at the chandlry. I changed out our engine intake to one because it's not protected against hard knocks, but the innards are identical to the ball valves: chromed brass or copper ball in a brass body (I forget). Thus, we don't bond our sea cocks. I don't lube our ball valves, but open and close them every time we sail. After 10 seasons' use, none show any problems. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ |
| Reply |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Forum | |||
| Cathodic Protection for Aluminum Hull - Need Help | General | |||
| Hull Waxing Question | General | |||
| Angle of prop shaft - theoretical question | General | |||
| Thru Hull Question | Boat Building | |||
| Narrow hull speed question | Boat Building | |||
Hybrid Mode
