Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > The Bosun's Locker > Repairs & Maintenance
Cruiser Wiki Click Here to Login

Join Cruiser Log Today

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-15-2008, 03:04 PM   #1
Retired Mod
 
Lighthouse's Avatar
 
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984
Default

A great primer article on thru-hulls and seacocks - HERE.

This stuff is really important to keeping your boat afloat.
__________________

__________________


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Old 10-20-2008, 04:07 PM   #2
Moderator
 
redbopeep's Avatar
 
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
Default

Quote:
Originally Posted by Lighthouse View Post
A great primer article on thru-hulls and seacocks - HERE.

This stuff is really important to keeping your boat afloat.
Yes! this a great resource about seacocks
__________________

__________________
"Do or do not. There is no try." - Yoda

What we're doing - The sailing life aboard and the Schooner Chandlery.

redbopeep is offline   Reply With Quote
Old 11-21-2011, 02:09 PM   #3
Ensign
 
The Cruising Kitty's Avatar
 
Join Date: Sep 2011
Posts: 11
Default

Just went to a lecture at the Cruising Association on the brass seacock situation in the EU. I am scratching my head.. definitely in the amazingbuttrue category.

In the EU, the European Regulations for Small Craft have been rewritten (1998) to say that fittings must be corrosion resistant - for at least 5 years! This applies to fittings beneath the waterline. And guess what, it seems that many manufacturers in the EU have started building yachts 'to standard'.

Confusing the issue further for boat owners is that even if you know you want bronze (or DZR) fittings, there is no requirement for this to be clearly labelled (or labelled at all) on packaging. Even chandleries are often not able to correctly identify what the parts they are selling are made of (according to the speaker at the CA lecture I went to).

Does the same situation exist in the USA? If I buy my fittings in the US can I solve this problem? Are US boatbuilders using brass seacocks?

Any insight would be much appreciated. Thanks in advance.
__________________
The Cruising Kitty
https://thecruisingkitty.com/
The Cruising Kitty is offline   Reply With Quote
Old 11-22-2011, 11:54 AM   #4
Admiral
 
JeanneP's Avatar
 
Join Date: Jul 2004
Posts: 2,098
Default

Bargain boat manufacturers tend to use bargain parts. After some issues with various gear, Peter and I search for Made in the USA cast metal parts. Groco, Perko, and Apollo are all US manufacturers of brass plumbing fittings, but I doubt you'll find a builder's spec. sheet that goes into that much detail about the quality of its plumbing fittings. Having heard of no problems with quality, I would venture to say that if it's made in the U.S. and says "brass", I would accept that as fact.

More commonly, you'll find Marelon fittings installed to save money. Since they are also lighter in weight, one might investigate whether these are more commonly found on multihulls. Most experienced sailors avoid Marelon due to their high (relatively speaking) failure rate. We have long memories when it comes to gear failure. But when looking at boats to buy, that is a "kicking the tires" and survey situation.

Not very helpful, am I? Sorry.
__________________
In 1986 we went cruising for a few years. After 20 years and 50+ countries and several oceans, we are STILL "cruising for a few years".

SY WATERMELON |
MV WATERMELON (New) | Cruiser's Dictionary, free ebook

= Cruiser's Dictionary, North America,
JeanneP is offline   Reply With Quote
Old 11-22-2011, 06:19 PM   #5
Moderator
 
redbopeep's Avatar
 
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
Default

It is my understanding that the reputable brands (including the three JeanneP lists) all make BRONZE not brass thruhulls and seacocks. Though a high quality brass may pass marine testing just as a bronze does. Bronze uses Tin whereas Brass employs Zinc in the alloy. Some brasses actually do quite well in salt water (see Naval Brass for example) but still, bronze thruhulls are likely best. In the US, you will find items which have passed appropriate testing for use on boats to be labeled "Marine UL Listed" or with the UL spec (e.g. UL-1121).

Reputable mfrs of seacocks and thruhulls include:

Apollo,

Blakes,

Groko,

Perko,

Willcox

I hope this information is helpful. You can find numerous retail suppliers who carry these thruhulls and seacocks.

I dare say that someone might use brass (not bronze) thru hulls for a very long time without failure due to de-zincification as long as the boat has a properly sized, placed, and maintained sacrificial anode. Even bronze seacocks will "pink" from electrical activity if the boat's anodes (typically zinc but sometimes mild steel or another material) are not properly sized, placed or kept in proper shape. In seawater, if the anode is not experiencing at least 400 millivolts (tested with a silver-silver chloride half cell and V-Ohm meter) it will not be doing its job and that means other metals on the boat will be sacrificed. That means brasses will lose their zinc and bronzes will lose their tin. Both leave behind a copper structure which is "pink" and not as strong as the original bronze or brass alloy.

Our boat is wood so we have to be very careful to assure that the we have just the right size of anode and maintain it. We use a zinc on the prop shaft but on the hull/keel/rudder interface, we use mild steel as, on our boat, zinc anodes are too aggressive and the wood adjacent to the anode could be damaged. So, we maintain between 500 and 630 millivolts. If we go over 800 millivolts or under 400 millivolts we risk damage to the wood and bronze/brasses respectively. We replace the zinc on the prop shaft every 8 months or so, the mild steel anodes are replaced every 4 months or so to maintain the proper voltage potential. Fiberglass boat owners don't have the same concern on hull material degradation and typically can go with a larger anode and longer between service.

Fair winds,
__________________
"Do or do not. There is no try." - Yoda

What we're doing - The sailing life aboard and the Schooner Chandlery.

redbopeep is offline   Reply With Quote
Old 12-05-2011, 07:03 AM   #6
Ensign
 
The Cruising Kitty's Avatar
 
Join Date: Sep 2011
Posts: 11
Default

Thanks both Jeanne P and redbopeep. These answers are about as comprehensive as it gets!

Looks like I will be heading to the US to pick up/replace my fittings. Good to know.
__________________
The Cruising Kitty
https://thecruisingkitty.com/
The Cruising Kitty is offline   Reply With Quote
Old 12-05-2011, 09:50 AM   #7
Admiral
 
JeanneP's Avatar
 
Join Date: Jul 2004
Posts: 2,098
Default

Thanks, Brenda, for catching my mistake. Bronze is what I meant to write, "Brass" is what I was thinking about warning against. Or, as a friend said many years ago, the fingers typing are faster than the brain thinking.

We had a brass fitting on the sailboat, and once when we hauled the boat, one of us accidentally hit the fitting and it shattered just like glass. The comments we heard were that the zinc in the brass acted the same as the sacrificial zincs we had on prop shaft and keel - sacrificed and leached out of the metal.
__________________
In 1986 we went cruising for a few years. After 20 years and 50+ countries and several oceans, we are STILL "cruising for a few years".

SY WATERMELON |
MV WATERMELON (New) | Cruiser's Dictionary, free ebook

= Cruiser's Dictionary, North America,
JeanneP is offline   Reply With Quote
Old 12-05-2011, 01:02 PM   #8
Ensign
 
Join Date: Dec 2011
Home Port: plymouth
Posts: 1
Default generators

Hi from jack mox so has anybody had any experience with sterling gen sets ie external combustion gensets i cant find any real info but need quiet power so one of these may be the way forward ( maybe
__________________
jackmox is offline   Reply With Quote
Old 08-08-2016, 08:31 PM   #9
Commander
 
Join Date: Jun 2016
Home Port: Royston
Posts: 127
Default

With steel hulls, welding in type 316 stainless sch 40 pipe nipples, with stainless ball valves on them, has given me zero problems in over 40 years.
__________________

__________________
Brent Swain is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Antifoul For Aluminium Hulls oldsurfie General Cruising Forum 3 08-23-2011 07:00 PM
Installing Through-hulls & Repacking A Stuffing Box Lighthouse Repairs & Maintenance 20 09-14-2010 03:37 PM
Fibreglass Hulls KevinBarr The Poop Deck 11 05-04-2009 05:44 PM
Ferro Hulls whatnot General Cruising Forum 1 01-14-2008 08:56 PM
More Or Less Number Of Below Water Thru-hulls redbopeep General Cruising Forum 11 09-08-2007 09:52 AM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


All times are GMT. The time now is 09:35 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0
×