Raw water pump. You can't get there from here

[skipmac]

With all this discussion I had to go back and reread the article on Maine Sail's site about brass and bronze. This is why brass makes me nervous.

Replacing Thru-Hulls and Seacocks Photo Gallery by Compass Marine at pbase.com

[boden36]

Anyone with a lathe can knock you up one in a few minutes.
Regards,
Richard.

[HopCar]

We can get into a huge conversation as to what is bronze and what is brass. In general what you see in marine stores is an alloy that has about 5% zinc and 85% copper, the rest being other metals. Groco uses 85-5 copper zinc in their strainers.

Some stores call it bronze others call it red brass but it's the same stuff. It's fine in salt water. You want to avoid yellow brass which can have up to 40% zinc.

You can buy 1" to 1/2" bushings, I sell them but I'm sure your neighborhood marine store will stock them as well.
Link: ACR Red Brass Hex Bushings 1"

[Watermann]

Fisheries Supply has exactly what you need in bronze (also sometimes called red brass):

Hex Bushings - Midland Metals | Fisheries Supply

Select the 1" x 1/2" and use 1/2" elbows and hose. Like hopcar said, yellow brass is what you want to avoid.

[sailorchic34]

Originally Posted by HopCar

[LEFT]

Some stores call it bronze others call it red brass but it's the same stuff. It's fine in salt water. You want to avoid yellow brass which can have up to 40% zinc.

You can buy 1" to 1/2" bushings, I sell them but I'm sure your neighborhood marine store will stock them as well.
Link: ACR Red Brass Hex Bushings 1"

Oh apologies to Hopcar. I should have said some coast to coast marine stores have some fittings that to my eye look like yellow brass. Generally the smaller / local marine stores have better bronze fittings.

BTW looking at the ARC listing, you list "Most durable of all metals for commercial water pipe in the practical price range. Excellent for its resistance to dezincification and season cracking for which the high copper brasses are known. Moderate strength and good retention of spring properties.

Hum... All bronze and brass have high copper content. Actually bronze as a rule will have a higher copper content, 76% up to 88%. 85,5,5,5 bronze is excellent with 85% copper, 5% tin, 5% lead and 5% zinc. Brass will have a lower copper content somewhere between 63 to 75 percent and more zinc and/or aluminum. Bronze may also have zinc and/or aluminum as well as tin and other materials in different concentrations.

Anyway I believe your ARC fittings listing should read high zinc content, or lower copper content when referencing brass.

With most bronze and brass being made with recycled materials today, the exact composition of the material is sometimes suspect. I believe even Groco had a bad batch of bronze there for a bit.

[Cheechako]

Iteresting side note: this month's Sail mag has an article by Nigel Calder regarding "seacock safety". There is a pic of an old bronze gate valve screwed onto a thru hull and along side it a new Ball valve (which Nigel calls a seacock!) screwed onto a thru hull. The ball valve screwed onto a thru hull is what Nigel implies is "proper".
Here's my point: if you look at the new ball valve and the thru hull it is screwed onto, they are very different in color... the valve being very yellow compared with the reddish bronze thru hull. Supposedly that valve is bronze, but I've never seen good bronze that yellow. I suspect he will get some mail regarding that....

[sailorchic34]

Originally Posted by Cheechako

Supposedly that valve is bronze, but I've never seen good bronze that yellow. I suspect he will get some mail regarding that....

My point exactly. Bronze has a redish tint to the casting. If it looks yellow, its not really bronze, or at least not a high quality bronze, despite what the manufacturer data may say. If Nigel gets caught with a brass ish valve, what is average Joe boater going to do.

Apolo / Cobranco does make a Bronze ball valve. But I've yet to see a real one in a marine store. The ones I've seen were yellow brass.

Interesting to note that the ARC listing Hopcar posted lists Brass ASTM numbers. Bronze ASTM numbers include B62, B103 and B150 etc. Brass and Bronze gets a little blury in the middle. Astm B134 and B135 is a brass spec for commercial plumbing. Astm B42 is for copper piping.

Someone with a gas spectroscope, should run a few "bronze" fittings through and see what they really are made of.

[Cheechako]

the pic: note the color of the valve vs the thru hull fitting..this is supposedly a marine approved bronze valve...

[JK n Smitty]

Originally Posted by skipmac

Already looked at both and maybe I'm missing something, but found only brass. I am afraid of mixing brass in the system. Would rather go with nylon or PVC

I stand corrected. It looks like they are not carrying as much bronze stock as they used to. Interesting.

Sorry to have mislead you.

[HopCar]

Sailorchic, I have to admit I don't know what ASTM numbers mean. Today I called my supplier and asked what the fittings I describe as "red brass" are made of. He dug out the MSDS which said it was 84 to 86 % Copper, 4 to 6 % Zinc, 4 to 6% Lead and I think he said 4 to 6% Aluminum. That sounds like 85-5-5-5 to me.

Should I call them bronze instead of red brass?

I've been buying and selling these same fittings for more than twenty years. They have been on my own boat for more than twenty years in salt water. Never seen one dezinc.

[sailorchic34]

You know, I knew you had a call into the supplier :-)

They are bronze, at the upper end of the bronze range. I would call them bronze, not brass.Though red brass is a proper term too.

Though due to the low lead laws, perhaps not quite as good as they once were.

Oddly enough the 85,5,5,5 fittings do de zinc, but its only 5% zinc so no big deal. But once the zinc is gone from micro galvanic action, the aluminum will start to go too. But that still leaves 90+ percent of the metal, which is probably not a big problem. It's a good material for below the water line fittings for sure.

When you get in the 20 to 35 percent zinc range, then you have a structural failure in the future.

Red Brass is sort of a generic term. It was also called gunmetal, as that is what the bronze cannon's on the man O wars were made of. Its generally 85,5,5,5 though in olden days it was lead, not aluminum. They changed to Aluminum to meet the low lead standard. Only problem with that is now you have 10% of the fittings subjected to micro galvanic action, where before it was only 5 percent.

Red brass is also a name for copper alloy C23000, which is 14–16% zinc.

[S/V Alchemy]

Originally Posted by skipmac

So in the course of installing new hoses for the raw water system, overhauling the strainer and installing a new raw water pump I have run into a road block.

The original strainer is a large Groco with 1" NPT female sockets on the strainer body. The Sherwood water pump has 1/2" NPT female sockets on the pump. So far I have not found a way to get from 1" to 1/2".

Groco sells elbows that are 1" NPT male with 1 1/8" or a 1 1/4" hose barb. I can get a 1/2" NPT elbow for the pump with 3/4" hose barb. Of course the ideal would be a step down fitting on the strainer that would take the 1" NPT out to a 3/4" hose barb. I cannot find such a think in bronze and don't want to go with brass.

Plan B would be a step down double ended hose barb but again I cannot find this in bronze.

So my options so far are

1. Buy a new strainer with 1/2" NPT fittings. Much smaller than the old strainer but big enough? Groco rep thinks the old strainer with 1" fittings is way overkill for a 60 HP sailboat diesel. Would save a little room in the engine space as well.

2. Stack up 2-3 brass fittings to get from the 1" NPT down to the 3/4" hose. I don't like no stinkin' brass in my raw water system.

3. Go to Home Depot and get a plastic (nylon, ABS, PVC, ?) step down hose barb. This is on the cold side of the raw water system.

OR - does anyone know where I can get a hose fitting to step down from 1 1 1/4" ID hose to 3/4" ID hose?

Thanks
Skip

If the 1/2 inch diameter of the raw water pump is sufficient, then a 1/2 inch strainer should be sufficient...assuming it is mounted at the "even keel" waterline so that the pump need not do much in the way of work to draw water into itself. The pump is there to send water through the much smaller engine passages.

I say this having what I think is a 5/8" Perko strainer on a 1/2" raw water pump (looks like a Sherwood) on a Beta Marine 60. Because it's not very pressurized on the intake side, I just double clamp it.

[HopCar]

Per Sailorchic's advice, I will change the description on my website from Red Brass to Bronze. Groco calls 85-5-5-5 bronze, I guess I can too.

[Rhapsody-NS27]

I had an issue when I bought a Groco strainer. I only saw the hose size of 3/4" from the seacock and ordered a 3/4" strainer. Then, I realized that the waterpump on the engine was 1/2". I couldn't find a bronze reducer anywhere. I ended up ordering another waterpump at 1/2" then used a full flow elbow that accepted a 3/4" hose for the seacock and a regular 1/2" for the waterpump. Similar situation.

This post on my blog shows what the strainer looked like with the correct fittings.

You may have to do the same to change the size of the strainer then get fittings that you need to accommodate both sides.

[Watercolor]

Skipmac - Look at the Hamilton Marine website and under plumbing and bronze fittings you'll find exactly what you need, a 1" to 1/2" bronze reducer bushing that will transform your old Groco strainer 1" female NPT threaded port into a 1/2" female NPT threaded port. Then all you need is two 1/2" bronze barbed adaptors and 1/2" hose.

I like Hamilton because it's still owned by the founder, Wayne Hamilton, and he seem to have the best selection of bronze plumbing around.

With regard to brass vs bronze. All current (and I believe past) US made seacocks and thru-hulls are made of made of Alloy #836, and contain 85% copper and 5% each of zinc, tin and lead. (AKA 85-5-5-5, leaded red brass, and Composite Bronze).

As far as I can ascertain only Spartan seacocks and the Apollo flanged sea valve use 85-5-5-5 exclusively. The others use some red (85% copper and 15% zinc) or yellow brass (65% copper and 35% zinc) for some internal components.
Some time ago West Marine got caught with it's pants down when they sold red brass nipple fittings as bronze. I have seen other instances where red brass (AKA Alloy 230) has mistakenly been referred to as bronze. The reason companies like Spartan, etc. use Alloy 836 is because the lead makes it easily machined and it has held up well in salt water conditions.

Fair winds