A/C Hoses

[34Hatt]

Jamestown has bronze nipples also!

 

[bigbill]

donovan marine has them in their catalog. have not had any trouble getting what i needed from them.

 

[captddis]

You need a Lewis catalog?

The Glen Mar catalog used to say Lewis on it, but Glen Mar has been dropping a lot of items.

 

[captddis]

donovan marine has them in their catalog. have not had any trouble getting what i needed from them.

The nipples I have bought from Donovan have been red brass

 

[GJH]

Jamestown has bronze nipples also!

Every one on Jamestown's site is brass. They carry Groco stuff but not the nipples. The Groco design is perfect for the purpose, next time I need one.

I do have a Lewis catalog on the boat, will take a look. I am sure I can order them directly or from a local shop ; we have some good ones here that service the boat builders, yards and commercial fleet. You can get just about anything bronze right off the shelf, except nipples, which was what I was whining about. Had the same experience in Ft Lauderdale though I didn't try Lewis there for it, not sure why since I bought other stuff from them. Could have ordered the Groco from BOW or Sailorman too, I suppose, though Sailorman usually uses Donovan for special orders. At some point, you say screw it I'm not driving all over town for a GD nipple, I'll seal it with TefGel and make sure the bonding is right, I'd rather be at Lester's Diner having a club sandwich and strawberry shake.

 

[bobk]

Bob, if the strainer/through hull and pump head are both bonded to the bonding system, could you explain why would galvanic corrosion take place? You certainly see a lot of brass sold in marine supply stores, and nipples in particular are almost impossible to find in bronze.

In my case the strainer was not mounted to the through hull and not bonded. It was an after market installation. The nipple on the shaft log was my first encounter with this on a boat and I think the only potential bonding would have been through the bonded shaft wiper, but that 25 years ago and I'm not real clear. I do remember taking the nipple to the marina parts department and getting a lecture that only bronze should be used in that application. Bonding or adding a zinc pencil would help. But then again, anodic protection of marine metals generally involves a sacrificial zinc. The zinc in the copper alloy may be doing that?

BTW, I can usually get what bronze I need at Lewis Marine in Port Salerno.

Bobk

 

[fissioneng]

But then again, anodic protection of marine metals generally involves a sacrificial zinc. The zinc in the copper alloy may be doing that?

That's exactly what's happening. If you let it go long enough the brass will turn pink as all the zinc is sacrificed. Many nipples are yellow brass which is ~30% zinc, red brass is ~5% zinc. Yellow brass is used a lot for nipples because it machines so easily. Bronze usually has no zinc in it.

I just found this link for Groco bronze nipples:
http://www.wholesalemarine.com/p/GRO-PN-750/Groco+Bronze+Pipe+Nipple.html