Looking for shop to make bronze fitting

[angus99]

Someone suggested in an earlier thread that I could work with a machine shop to have a couple of small bronze hose barbs manufactured. These are 3/8” hose to 3/8” NPT adapters for the shaft log water lines that provide water to deeply embedded (in the hull) cutless bearings and areas of the prop shaft that would otherwise be susceptible to crevice corrosion.

Currently, I have stainless barbs, but want to remove these dissimilar metals below the waterline while the boat’s on the hard this winter and stick with all bronze.

I’ve checked all the major suppliers such as Groco, Buck A, McMaster Carr and many others— and NOBODY seems to make a true bronze hose barb in this size. Everything’s brass, plastic or stainless.

So a good machine shop that does this kind of work seems to be the next option.

Thanks in advance.

 

[Maerin]

Someone suggested in an earlier thread that I could work with a machine shop to have a couple of small bronze hose barbs manufactured. These are 3/8” hose to 3/8” NPT adapters for the shaft log water lines that provide water to deeply embedded (in the hull) cutless bearings and areas of the prop shaft that would otherwise be susceptible to crevice corrosion.



Currently, I have stainless barbs, but want to remove these dissimilar metals below the waterline while the boat’s on the hard this winter and stick with all bronze.



I’ve checked all the major suppliers such as Groco, Buck A, McMaster Carr and many others— and NOBODY seems to make a true bronze hose barb in this size. Everything’s brass, plastic or stainless.



So a good machine shop that does this kind of work seems to be the next option.



Thanks in advance.

Why not nylon? Very tough, not brittle, non-reactive. Won't require a mortgage. You'll have to be very specific with the alloy to have it made in bronze.

 

[angus99]

Why not nylon? Very tough, not brittle, non-reactive. Won't require a mortgage. You'll have to be very specific with the alloy to have it made in bronze.

Thanks, Steve.

The hose barb sticks out at an acute angle from a very solid bronze casting deep in the bilge and holds the hose in—what seems to me—a vulnerable position. While it’s fairly well protected overhead, I’m thinking something heavy hitting the hose might break a plastic/nylon fitting.

Since it’s well below the waterline, I’m thinking the hose barb should be as robust as any other through hull fitting. I’d use Marelon, but they don’t make a 3/8.

But I may also be over-thinking this.

 

[DavidM]

You might want to see if you can find the fitting in Marelon, a glass reinforced nylon made by Forespar. Marelon is tough enough to be used for sea cocks.

David

 

[caltexflanc]

If you are worried about the bronze/stainless junction, use Tef-Gel or equivalent in the threads, that's what it is made for, joining dissimilar metals. Speaking of over tinking it, just curious, how long have the stainless barbs been in there and what condition are they and the bronze in?

 

[Ski in NC]

Any one with a lathe, mill and a 3/8npt die can make such out of a bronze bolt or piece of shaft.

I too would not be too freaked out about using nylon or similar.

 

[dhmeissner]

Marine Hardware

Call Pete at Port Townsend Foundry, I’m not sure if they make what you’re looking for though.

 

[smitty477]

I believe that Groco makes a 3/8 hose to 1/2" npt that you can likely easily reduce in marine bronze. Or perhaps a larger hose that is reduced up line as well.

 

[psneeld]

Use nylon or stainless, even PSS dripless shaft logs use cheap nylon hose barbs as injection points.

There is so much worry on this forum about things commonly done that I just am amazed.

 

[Adagio43]

Try giving Robinhood Marine in Georgetown, ME a call 800-255-5206.
They manufacture their own bronze seacocks (Spartan) and may be able to help you out.

 

[Brooksie]

You could make them yourself. Go to a good plumbing supply. Get 1/8x3/8 RED brass bushings and 1/8" RED brass 4" nipples. Cut the nipples in half, chuck in your drill or drillpress and cut some barbs in them with a file while spinning. Red brass is fine with bronze in salt water. I have had two of the above on my elbow drain for 10 years and they are still fine.

I have the same concerns about expensive gear that comes with brass, plastic or stainless small barbed fittings.

 

[Xsbank]

Red brass is high in zinc, which is fine for fresh water applications but not in salt. Bronze is low in zinc, hence its use on boats.

 

[Xsbank]

Here you go, found one:Bronze Hose Nipples Marine Hose Fittings Hose Barbs Hose Connectors Gunmetal Hose Barbs Hose Tails

 

[angus99]

Here you go, found one:Bronze Hose Nipples Marine Hose Fittings Hose Barbs Hose Connectors Gunmetal Hose Barbs Hose Tails

If they are what Conex claims, drinks are on me, Xsbank. I wore Google out looking for those. Apparently, the’re made in India. I’ve contacted them and we’ll see if they’re 85-5-5-5 and available in small quantities.

If this doesn’t pan out, I’ll try a local machine shop or reconsider nylon.

I appreciate all the good ideas.

Dave, Forespar doesn’t make them in Marelon smaller than 1/2”.

caltexflanc, I installed the SS barbs a few months ago. I’m sure they’re fine, but am looking for a long-term solution.

Scott, I always appreciate your advice but wish it didn’t have to come with an editorial. If this were “commonly done” by me, I wouldn’t be asking. If I want to bullet-proof my bonding system and sleep better, why is that an issue?

 

[kapnd]

A 90 degree fitting positioned downwards would make it far less vulnerable to damage.

 

[Xsbank]

Woohoo drinks! You’re welcome!

 

[psneeld]

If they are what Conex claims, drinks are on me, Xsbank. I wore Google out looking for those. Apparently, the’re made in India. I’ve contacted them and we’ll see if they’re 85-5-5-5 and available in small quantities.

If this doesn’t pan out, I’ll try a local machine shop or reconsider nylon.

I appreciate all the good ideas.

Dave, Forespar doesn’t make them in Marelon smaller than 1/2”.

caltexflanc, I installed the SS barbs a few months ago. I’m sure they’re fine, but am looking for a long-term solution.

Scott, I always appreciate your advice but wish it didn’t have to come with an editorial. If this were “commonly done” by me, I wouldn’t be asking. If I want to bullet-proof my bonding system and sleep better, why is that an issue?

Sorry, didnt mean to point the finger too specifically.....but it is true, there is so much wringing of hands about making boats perfect....and who is the real expert source causing all this concern?

Long before I got in tbe marine trades, I read every boating magazine and was scared into believing my boat had to conform to all these "writers" opinions. Then slowly but surely I learned to sift through the "perfect boat" articles and what is perfectly acceptable.

Nylon is used by one prominent manufacturer and stainless by a lot of marine trade guys I have worked with.

Sorry again,....... if still looking for bronze I cant help but if stumped, there is a place selling cupro nickel that I can post, just dont have it handy now.

 

[angus99]

Sorry, didnt mean to point the finger too specifically.....but it is true, there is so much wringing of hands about making boats perfect....and who is the real expert source causing all this concern?

Long before I got in tbe marine trades, I read every boating magazine and was scared into believing my boat had to conform to all these "writers" opinions. Then slowly but surely I learned to sift through the "perfect boat" articles and what is perfectly acceptable.

Nylon is used by one prominent manufacturer and stainless by a lot of marine trade guys I have worked with.

Sorry again,....... if still looking for bronze I cant help but if stumped, there is a place selling cupro nickel that I can post, just dont have it handy now.

I understand where it was directed now, Scott. Sorry for my reaction.

 

[Brooksie]

Red brass is high in zinc, which is fine for fresh water applications but not in salt. Bronze is low in zinc, hence its use on boats.

2-3% is not high, most has arsnic added to prevent dezincafacation.

 

[AusCan]

If they are what Conex claims, drinks are on me, Xsbank. I wore Google out looking for those. Apparently, the’re made in India. I’ve contacted them and we’ll see if they’re 85-5-5-5 and available in small quantities.

There are some top notch fittings suppliers in India.

I was working over there a few years ago preparing for some work on an offshore oil rig. An oversight on my behalf meant I needed some certified 15,000 psi specialized fittings in a hurry, so I contacted our normal supplier in Houston to see if they could air freight some out immediately. In turned out that the Houston company got them from an Indian supplier only 10 minutes away from my hotel.

 

[Chrisjs]

I would have expected the stainless steel fittings to be stronger than any of the options discussed. Surely just wrapping the threads with a couple of turns of Teflon tape gets rid of the electrical contact, dissimilar metals issue?

 

[psneeld]

Tape might, but often does not keep continuity from happening.

People said they tried it with their pencil zincs to stop leaks but still got 0 ohms.

If the combo is tied to the bonding system, much like your bronze prop and stainless shaft, it shouldnt matter.

 

[kapnd]

It takes luck and a lot of tape to prevent electrical current from passing through a thread fitting, especially one with tapered threads.

 

[T4Liberty]

I had some luck recently with these folks making items I couldn't find elsewhere.

https://www.hoseandhydraulic.com/

 

[ghost]

I've run into this before. While you may not find a hose barb, you should be able to find a reducer which will allow you to go up to say 1/2 and just go with the next size hose up. At least I think so. Basic fittings are easier than the barbs. No idea why.