Home Depot Plumbing fittings - just bad or really bad?

[Tellie]

[quote=Acoustic;208090]Be very very careful with the above advice:


We were talking PVC ball valves and nylon barbed fittings not household brass valves or brass anything. I'll stand HD nylon fittings for watermakers etc. against any over priced West Marine nylon hose barb any day of the week. I know some folks sleep better after they've over paid, so be it.

[w42]

Originally Posted by Tellie

Be very very careful with the above advice:

That goes without saying. Be very careful with ANY advice you get on the internet. Including mine

[Maine Sail]

[quote=Tellie;208280]

Originally Posted by Acoustic

Be very very careful with the above advice:


We were talking PVC ball valves and nylon barbed fittings not household brass valves or brass anything. I'll stand HD nylon fittings for watermakers etc. against any over priced West Marine nylon hose barb any day of the week. I know some folks sleep better after they've over paid, so be it.

Sorry when you say "assorted HD hose barb fittings are fine." I assumed you meant the "assortment" of fittings they stock at Home Depot such as nylon, brass and PVC. It does not change the fact that many of these still can't be double clamped.

Originally Posted by Tellie

assorted HD hose barb fittings are fine.

I don't buy the nylon junk at West Marine either as even those barely fit two clamps. As for paying to much I pay far less than most being an owner of a marine business. My discounts at Hamilton Marine, Defender, Port Supply and Jamestown keep me there as the prices are usually as good or better on many items than at Home Depot. Sure I buy lots at Home Depot, like domestic plumbing PEX tubing, but not critical stuff that has the potential to sink a boat.

For bellow water fittings and circuits I use only UL marine bronze or Marelon. I've seen many Marelon failures but none that would sink a boat quickly and I've also seen my fair share of dezinctification of bronze so there is no silver bullet.

Those nylon barbs can be snapped of fairly easily and should be left to domestic water or sanitation use not bellow waterline applications..

I personally, on my own boat, snapped a thru-hull fitting when a spare alternator hit the valve in rough seas. No PVC for me and I now only install through bolted seacocks and not just a valve on a thru-hull.

Brass, nylon and PVC are fine for domestic h2o or sanitation plumbing as your poop and drinking water won't sink your boat. They'll just stink your boat...

[Thermal]

I have a rule: No plastic fittings in hoses that connect to the ocean. I would like to include yellow brass in that category too, but it seems thats all you can get these days. Beware of "bronze" fittings at We$t Marine - a lot of them are actually yellow brass. PVC would be OK for fresh water systems, etc. - after all, you can't sink a boat with water that's already IN the boat

[Maine Sail]

Originally Posted by Thermal

I have a rule: No plastic fittings in hoses that connect to the ocean. I would like to include yellow brass in that category too, but it seems thats all you can get these days. Beware of "bronze" fittings at We$t Marine - a lot of them are actually yellow brass.

That's because you shop at the wrong chandlery!

Hamilton Marine has a great selection of bronze hose adapters. In the last 13 years I have never not been able to find the right hose adapter in bronze.

Hamilton Marine Hose Adapters (LINK):

[Thermal]

Originally Posted by Acoustic

That's because you shop at the wrong chandlery!

Unfortunately We$t Marine is the only chandlery within 2500 miles - like a marine Wal-Mart (NEW higher prices every day) at 10% over list price since it costs more to ship the stuff only half as far from China.

Still, Hamilton Marine seems to be selling the same BRASS nipples as HD in place of the bronze ones that are rather conspicuous in their absence

[Maine Sail]

Originally Posted by Thermal

Still, Hamilton Marine seems to be selling the same BRASS nipples as HD in place of the bronze ones that are rather conspicuous in their absence

Perhaps you missed the link to Hamilton's large selection of BRONZE adapters in my post above?

Hamilton Marine BRONZE Adapters (LINK)

Yes of course Hamilton does sell brass nipples and nylon too but they are intended and should be used above the water line for domestic or sanitation systems only..

[Thermal]

Originally Posted by Acoustic

Perhaps you missed the link to Hamilton's large selection of BRONZE adapters in my post above?

No, I saw those. Problem is: Adapter is not a Nipple



and when need a nipple below the waterline you're SOL

[Maine Sail]

Originally Posted by Thermal

No, I saw those. Problem is: Adapter is not a Nipple



and when need a nipple below the waterline you're SOL

If you follow ABYC recommendations you would not install one. Also there should not be a need for a nipple bellow the waterline. In 35 years of working on and around boats I've yet to come across a situation where a nipple was necessary...?

Can you point us to a situation that meets standards and would require a nipple??

That being said I really don't understand why no one makes a bronze nipple just red brass which BTW is supposed to have less than 15% zinc and is MUCH more resistant to corrosion than yellow brass.

The amount of Zinc in Brass varies from 5% to 45%, with the 60/40 or 70/30 (copper/zinc) alloys being the most common and causing Brass components made from 60/40 to be pretty good sacrificial anodes! If the Zinc content is less than 15%, the addition of 1% Tin or other alloys will make it reasonably resistant to stress-corrosion cracking and dezincification. The 60/40 (yellow brass) brass alloys are susceptible to dezincification and stress-corrosion cracking under appropriate conditions such as immersion in stagnant or slowly moving seawater.

There are different types of brass but most all Home Center brass contains high amounts of zinc. Red brass is supposed to have bellow 15% zinc and is highly corrosion-resistant. Yellow brasses contain from 34 to 37% zinc and can dezinctify rather quickly. Cartridge brass contains 30-33% zinc and is slightly more corrosion resistant than yellow. Muntz metal is garbage and much of the junk ball valves coming out of China for distribution in home centers today is Muntz brass containing up to, and in some cases over, 40% zinc.

The nipples at Hamilton, according to Midland Metals who is Hamilton's supplier, are are red brass, and are 15% zinc NOT 40%! These nipples should NEVER be confused with home center Muntz metal brass nipples containing upwards of 40% zinc! Brass is not ALL created equal!! If you use brass on a boat bellow the waterline make sure it's RED BRASS!!

ABYC Standards:

"ABYC Standard H-27 Seacocks, Thru-hull Connections, and Drain Plugs:

All materials shall be galvanically compatible and resist degradation to salt water, petroleum products, UV light, ozone, cleaning components likely to be encountered, marine growth, and the effects of heat aging. Copper-based alloys shall meet the requirements of the 10 Day Moist Ammonia Air Stress Cracking Test in UL 1185, Portable Marine Fuel Tanks (Note: This reference appears to be an error and should be UL Standard 1121).

UL Standard 1121 Marine Through-Hull Fittings and Sea-Valves:
Materials: The components of a through-hull fitting or sea valve shall be formed of galvanically compatible materials having the strength and resistance to corrosion necessary to withstand intended and abnormal use to which they are likely to be subjected.
A part made of drawn brass or machined from brass rod containing more than 15 percent zinc shall be subjected to the 10-Day Moist Ammonia-Air Stress Cracking Test (Section 19). After being tested, a brass part containing more than 15 percent zinc shall show no evidence of cracking or delamination when examined using 25X magnification.

[Tellie]

Acoustic, since obviously this is part of your buisness. Could you elaborate on below the waterline centrifugal pumps? I've seen alot that have not only plastic barb connections but plastic housings as well. Some air conditioning cooling pumps for example.

[neelie]

It seems this is turning into a religious debate - a bit like the mono-v-multi and balsa-v-foam.

Lets see if I understand the advice I am getting:
First PVC is the Antichrist, then Stainless is no good because of crevice corrosion, also any non metal fittings (Marelon) are no good because they may break when the engine falls on them, bronze in whatever guise suffers from de-zincification so that leaves 2 possibilities:

1) Copper Nickel Alloy or 2) Titanium.

Bullet proof fittings are all very well but they are mere ends to what is a very fragile hose - which is the much maligned plastic material, it ages, it splits and it s certainly not bullet proof.

Are we all not too intent on building the strongest link in what is a very weak chain and thus not seeing the forest for the trees?

(Note: I exclude any thru hull fittings from the above comments, these can never be too strong)

[MidLandOne]

Seems that the golden rule is NEVER use plastic in a plastic boat doesn't it.

As an aside I find the commonly expressed dislike of stainless steel valves, seacocks and pipework commonly expressed on amateur forums particularly intriguing as it is widely used in high quality vessels as the material of choice, especially in aluminium ones . I guess the professionals who design and build them don't know what they're doing?

John

[David M]

I used stainless steel valves in an aluminum boat for 12 years. It was an inspected boat and the coasties would not allow plastic valves in a subchapter-T vessel. The valves never stuck and never corroded.

[Microship]

Great thread... thanks for all the info, which has me making notes for things to check on my boat's raw-water system.

Related question: I'm working on the "waterworks" with UV sterilizer, watermaker, and system of valves to allow quite a bit of reconfiguration. Except for RO input, it is all fresh water; except for tees into existing tankage inputs, it is all well above waterline.

It's mostly going on a single vertical panel in a clean area (not engine room). Just with the key components on hand already, I have two flavors of NPT, Guest quick-connects, and barbs various from Katadyn. So my question is this: what kind of valves (mostly stopcocks) have the best history of long-term smooth operation, provision for mounting to a panel, and availability outside the overpriced marine marketplace? And, if you could standardize on one hose/fitting type for fresh water, what would it be?

When I built the Microship hydraulic system, I went with industrial plastic stopcocks and small quick disconnects (forgot the vendor - but all from McMaster-Carr and laboratory supply places - photo here), though at least some of this system needs to minimize flow restriction (incoming dock water), suggesting 1" hose.

Many thanks,
Steve

[GordMay]

Originally Posted by Acoustic

... The nipples at Hamilton, according to Midland Metals who is Hamilton's supplier, are are red brass, and are 15% zinc NOT 40%! These nipples should NEVER be confused with home center Muntz metal brass nipples containing upwards of 40% zinc! Brass is not ALL created equal!! If you use brass on a boat bellow the waterline make sure it's RED BRASS!!...

Common names such as “Red Brass” or Muntz Metal are very nearly meaningless, without accompanying composition or Numbering System (UNS or other) specifications.

There are several, so called, “Red Brass” alloys, including:
U.S. Government bronze specification G is a Red Brass (gunmetal) composed of 88% copper, 10% tin, and 2% zinc.
U.S. Government bronze specification H is composed of 83% copper, 14% tin, 3% zinc, and 0.8% phosphorus.
And more ...