Brass Seacocks -

[goboatingnow]

I believe Spartan is the only company left producing bronze seacocks. I wonder what conclusion can be drawn from this ?

Dave

[Andrew Troup]

"Brass seacocks" seems to me to be an oxymoron

(like, say "Intelligence Agencies", "Mobility Scooters", "Oil Production well", or - my favourite - "Reality TV")

"Brass lakecocks" or "rivercocks", I can relate to.

[goboatingnow]

well , what I think has killed the seacock market is not Brass or Bronze, its the near universal use of thru hulls and ball valves. MOst tapered seacocks weeped, ball valves dont. Its easy and cheap enough to get Bronze thru hulls and valves ( mind you usually with chromed CW617N balls).


Dave

[S/V Alchemy]

Originally Posted by goboatingnow

Sure we can all afford custom boats. And I agree there are huge flaws.

However ...

The conclusion " I'm just not sure I'd like to go to sea in them" is not justified. They are by design " good enough"

Dave

My custom boat, being steel, was reasonably priced compared to new. You could, in fact, have probably afforded it.

"Not wanting to go to sea in one" is justified by my own experience and opinions on what I think is seaworthy and seakindlly. "Good enough" is a moving target in terms of personal tolerances and industry or governmental regulation. I don't like the "good enough" minimums for house construction, either. "Rated Lloyd's Ocean A" seems a bit of a sick joke to me, and yet it's a phrase trotted out to the newbies at boat shows as if it's a meaningful measure of ultimate seaworthiness.

Brass below the waterline is not "good enough" for me. That's the end of the story. I don't really care what other people will tolerate, or of which what material qualities they will choose to be ignorant or under-informed.

My family goes on our boat. I know what has been installed where, and how to fix it if it goes wrong, for the most part. Accepting substitutes or inappropriate materials for the application, as I deem brass seacocks to be, is not really how I roll, although it's amazing what you can acquire from non-marine sources that are, in fact, acceptable on the seaworthy boat.

I need no further justification than my own experience and planning and time served, because I am not the pimp here. The marketing branches and QC departments of the boat building industry are in that role, and like pimps, their mortal enemy is a strong light that reveals the patchwork, spackle and shortcuts.

[Watercolor]

Blake, British, uses a processed brass that is treated so that the zinc etc. are removed from the immediate surface of the item.

All the bronze seacocks manufactured in the US (Oerko, Groco, Spartan, etc.) use leaded red brass (85-5-5 copper tin zinc). My guess is that this material has been used for 50 years plus. It's softer less expensive and therefore easily machinable.

Regarding titanium, yes it is very corrosion resistant, however, when combined with bronze or stainless it simply increases the galvanic process and cause the bronze and SS to corrode at a quicker rate.

[noelex 77]

Originally Posted by Jedg

Regarding titanium, yes it is very corrosion resistant, however, when combined with bronze or stainless it simply increases the galvanic process and cause the bronze and SS to corrode at a quicker rate.

A titanium seacock would not cause problems with any of the other underwater metals unless it was electrically connected to them.
It should be technically possible to produce a totally titanium seacock (removing concern about dissimilar metals in the fitting itself). No commercial product like this exists although if could be produced at a reasonable price I think there would be strong market demand

[Stumble]

Originally Posted by noelex 77

A titanium seacock would not cause problems with any of the other underwater metals unless it was electrically connected to them.
It should be technically possible to produce a totally titanium seacock (removing concern about dissimilar metals in the fitting itself). No commercial product like this exists although if could be produced at a reasonable price I think there would be strong market demand

We are actually working on bringing these things to market, but right now the design of the valve is a pretty big sticking point. Assuming we can find a reasonable design and that there is enough demand, it probably wouldn't be that expensive relative to bronze. Just as a WAG I would think a 3/4" thru-hull and flange would be

Thru-hull - $20
Flange with valve - $60

So about $80 for a complete setup. So a little more than bronze, but not terribly so. We have the thru-hulls right now priced at $45 a piece right now, but there would be a significant quantity break for large orders, and an even bigger break once we started casting them instead of machining them. This is assuming cp2 titanium, which is roughly two and a half times as strong as the bronze Groco is using, half the weight, and will litterly last forever in normal service.

As mentioned above, titanium should not be used in direct contact with bronze, or heaven forbid crap brass under the water line. Titanium is the most cathodic of the structual metals, and electrolysis would be a major problem, particularly with the zinc in the brass.


For now a titanium thru hull fitting is really just a drawing board issue, but if someone has a design for a ball valve they would be interested in having made it would take about six weeks for us to put a machined one on the shelves, and maybe another six weeks to get a cast one. The problem for now is simply the design.

[Watercolor]

Noelex77 - thanks for the info.

My choice for a seacock would be a plastic designed for a marine environment, with strength characteristics similar to that of a fiberglass hull, like TPU.

Definitely not a material that degrades significantly in water like Marelon a 50 year old technology (Marelon is Dupont GR Nylon 70G13LBK (seacocks and fittings and 8018HS thru-hulls).

[delmarrey]

About 10 years ago I made a 4" OD X 7' rudder shaft for a friends racer, from grade 5 titanium. The material cost him $6000 + my machine work and then had some webbing welded on for the core and skin.

Titanium is real nice but the average boater will not buy it. As often as one needs to haul out it's less expensive to just replace the bronze each time. And then you'll still have to use bronze fittings attached unless one could find them in titanium also.

Good luck trying to sell the stuff.

[noelex 77]

I thought you might be reading these threads Greg

Those costs to me look very reasonable. In replacing seacocks a very big part of the bill is labour and time on the hard.
Boatyard labour is very expensive. Many owners are reluctant to do work which has a direct impact on the watertightness of the hull and therefore often employ a professional for this sort of work.
Combine these labour costs with the costs of sitting on the hard and the material costs are less significant.
This is one of the reasons the use of brass seacocks is so annoying. A small increase in manufacturing costs would save much more in ongoing maintenance costs, even without considering the safety aspect.

Hopefully with a few more educated consumers you can sell titanium seacocks to the manufacturers and save everyone a lot of headaches.

[Watercolor]

I believe there was a titanium components manufacturer (west coast company?) that was at the boat shows or in the boating magazines about 7 years ago with hose clamps and barbed fittings.

Anybody know what happened to them?

[Stumble]

Originally Posted by delmarrey

About 10 years ago I made a 4" OD X 7' rudder shaft for a friends racer, from grade 5 titanium. The material cost him $6000 + my machine work and then had some webbing welded on for the core and skin.

Titanium is real nice but the average boater will not buy it. As often as one needs to haul out it's less expensive to just replace the bronze each time. And then you'll still have to use bronze fittings attached unless one could find them in titanium also.

Good luck trying to sell the stuff.

Del,

I can't argue about what you spent. But our price for titanium tubing is right at about $30/kilo, with minor variation for wall thickness and size. As an example, I just sold 100 foot of 3" tubing for $1,620. At today's prices, even if that rudder stock was a solid 4" bar (which would be insainly overbuilt... The rough tensile strength of it would be 1.73 million pounds) it would only cost about $2700.

And we already make a complete line of fitting, just need the stupid ball valve.

[noelex 77]

Originally Posted by Jedg

Noelex77 - thanks for the info.

My choice for a seacock would be a plastic designed for a marine environment, with strength characteristics similar to that of a fiberglass hull, like TPU.

Definitely not a material that degrades significantly in water like Marelon a 50 year old technology (Marelon is Dupont GR Nylon 70G13LBK (seacocks and fittings and 8018HS thru-hulls).

Every aluminium boat owner has an interest in non metallic seacocks. TPU is new to me what are the pros/ cons of TPU and Marelon.

[Stumble]

Originally Posted by Jedg

I believe there was a titanium components manufacturer (west coast company?) that was at the boat shows or in the boating magazines about 7 years ago with hose clamps and barbed fittings.

Anybody know what happened to them?

They got hit with a couple of copyright violations from what I understand. This is why we are trying to find current manufacturers that want to work with us to make these parts. So we don't have to redesign the parts from the ground up, then pay for product testing, and the whole r&d costs just to bring something to market that's pretty much the same as what's already there, but in a different material.

[delmarrey]

Originally Posted by Stumble

Del,

I can't argue about what you spent. But our price for titanium tubing is right at about $30/kilo, with minor variation for wall thickness and size. As an example, I just sold 100 foot of 3" tubing for $1,620. At today's prices, even if that rudder stock was a solid 4" bar (which would be insainly overbuilt... The rough tensile strength of it would be 1.73 million pounds) it would only cost about $2700.

And we already make a complete line of fitting, just need the stupid ball valve.

I've machined hundreds of pounds of titanium for Air Research and Boeing parts over the past 45 years I can tell you that the stuff takes time and tooling to machine the stuff. Even more so then 316L SS. To cast the stuff it take over 3200º F. So the dies would be expensive as well and have to be injected, even more expense.

I don't see how the cost of manufacturing would make it reasonably priced enough for the average boater. Maybe for space shuttles or F/A-18F Super Hornets, or here in my own shop for myself.

BTW- I'd go with Jedg! Hi-pro plastics is the way to go IMHO. Less costs and no corrosion. Just keep'm clean and lubed.