Through hulls in Moody Yachts

[Annebrobson]

Does anyone know what brand/alloy of through hulls were used in Moody yachts built in the early 2000s? We are currently selling our 2003 Moody 47 in the USA. The buyer's surveyor has raised a query about the quality of the through hulls, they apparently do not meet US standards. We have had no problems with any of the through hulls, all but one are originals. They have been reguarly worked and checked, we had an extra anode fitted several years ago and annually replaced all anodes and repainted. The surveyor found them all to be sound.

[Pete7]

Ann, I doubt that the average owner can identify the yellow metal used for through hulls since there are no markings on them. Slightly different for seacock valves which are often labelled and therefore you can tell if its bronze, DZR or cheap brass. The valves may not meet the American standards as it was manufactured in the UK. Your yacht will however, meet Lloyds standards and likely you have a plaque inside like mine to say this. You could point this out to the surveyor who if knows his stuff will understand.

You could also ask the surveyor why he thinks they don't meet the standard, at a guess it's down to either bonding. American yachts are bonded, European yachts are not, or Moody have used bronze mushroom seacocks, rather than the bolt through. Nothing wrong with this approach.

I believe my through hulls are bronze and after 30 years still in good condition, but it is an earlier generation Moody. The couple of DZR seacock valves fitted sometime during its life are now being progressively replaced.

Some back ground reading:

Brasses and bronzes – Cox Engineering

Good owners association at:

http://moodyowners.org/

[Kenomac]

If this helps.. our 2001 Oyster 53 required all the through hulls to be replaced two years following purchase. They were made of an alloy DZR bronze in common use at the time throughout Europe, which came with a buyers warning to change them after five years. We did have a failure which led to our decision to change them to USA produced Apollo Naval bronze fittings. Another friend on an Oyster 53 also changed his out following a failure.

Your Moody fittings from the same vintage are probably the same; I would change them just to be safe.

Oyster did switch back to using only naval bronze just a few years after our boat was manufactured.

[Dockhead]

The early 2000's Moodys used Maestrini Bronze underwater fittings which are still available from ASAP Supplies in the UK. These are top quality real bronze fittings with a useful life limited only by the useful life of the steel parts in the ball valves.


I have been replacing mine gradually, and did a bunch of them last year before going to the Arctic, but that is purely prophylactic. I cut a few of the old ones apart and they were in perfect condition after 17 years apart from deteriorated mild steel handles on some of them.



There is certainly no issue with quality; what the surveyor is referring to probably is the prejudice in the U.S. against mounting ball valves directly to through hull mushroom fittings, in favor of real sea cocks with flanges. Arguably real sea cocks with flanges are stronger and better, but this is a U.S. thing -- ALL European boats built in the last 20 years use ball valves on mushroom fittings, and if done competently with quality fittings they seem to be fine.



One reason why ball valves are not in favor in the U.S. is because U.S. pipe threads as used on mushroom fittings and as used on ball valves are incompatible with each other NPT and NPF or something like that. European boats use BSP (British Standard Pipe) threads which do not have this issue.


Note that standards in Europe allow total crap plain brass fittings to be used provided they last 5 years, and that standard was gleefully taken up by the bean counters at Groupe Beneteau and other mass production yards. It looks like, based on Kenomac's post, that even a great yard like Oyster got caught up in the value engineering frenzy. But the other quality yards like HR, Discovery, Contest, Malo, Swan, Moody, etc. did not go that way -- quality bronze was always used, and you need not be concerned about such fittings as long as they open and close well and are not corroded, and did not get involved in stray currents or such.

[Kenomac]

I don’t doubt what Dockead wrote, but these DZR fittings were and still are so commonly used over here in Europe, that I personally wouldn’t place any faith in what any of the boatyards from that era tell you or me. Since you can’t tell the difference by looking at the thru hulls... change them for peace of mind.

These inferior fittings could have very easily been mixed in with the good ones at the time of manufacture. Oyster didn’t come out and tell me and others this DZR carp had been used, I only found out following a failure when a large waste flange broke off in my hand.

Bonding is another issue.

[GordMay]

Greetings and welcome aboard the CF, Anne.


“DZR” fittings/valves may have “CR” (Corrosion Resistant) cast into the body.

Fittings marked “CW617N”, are high zinc content brass suitable only for fresh water domestic purposes.

[deblen]

https://www.pbase.com/mainecruising/..._primer&page=2


https://www.facebook.com/watch/?v=537797726362231

[Kenomac]

Originally Posted by deblen

https://www.pbase.com/mainecruising/..._primer&page=2

I’m not sure what was meant by posting this... Our boat has Marilon ball valves without flanges, and we feel perfectly safe... no insurance issues.

[deblen]

Originally Posted by Kenomac

I’m not sure what was meant by posting this... Our boat has Marilon ball valves without flanges, and we feel perfectly safe... no insurance issues.

I don't understand this post. It has nothing to do with your Marelon fittings.



The OP asked about metal alloy used in their boat.
Dockhead made a comment about BSP (British Straight Pipe thread) working fine on BPTapered thread????
The link I provided is an excellent description of the possible weakness of using straight thread mushroom thru hull skin fittings threaded directly into tapered thread female valves,ells,etc.
Len

[Dockhead]

Originally Posted by deblen

I don't understand this post. It has nothing to do with your Marelon fittings.

The OP asked about metal alloy used in their boat.
Dockhead made a comment about BSP (British Straight Pipe thread) working fine on BPTapered thread????
The link I provided is an excellent description of the possible weakness of using straight thread mushroom thru hull skin fittings threaded directly into tapered thread female valves,ells,etc.
Len

As I wrote, the straight vs tapered thread issue is limited to the U.S. All through hull fittings and ball valves sold in Europe and, in fact, everywhere except the U.S., are BSP and compatible with each other.


How it is that incompatible NPT and NPS fittings got to be sold in the U.S., and apparently are still sold, must an interesting story, but I don't know it.

[Dockhead]

Originally Posted by Kenomac

I don’t doubt what Dockead wrote, but these DZR fittings were and still are so commonly used over here in Europe, that I personally wouldn’t place any faith in what any of the boatyards from that era tell you or me. Since you can’t tell the difference by looking at the thru hulls... change them for peace of mind.

These inferior fittings could have very easily been mixed in with the good ones at the time of manufacture. Oyster didn’t come out and tell me and others this DZR carp had been used, I only found out following a failure when a large waste flange broke off in my hand.

Bonding is another issue.

Well, you can tell the difference by just looking at them -- look for what is stamped on them. If you see the Maestrini logo and "BRZ", you can rest easy. Even the balls in those are chrome plated bronze, not brass -- that's quality kit (I wish however they would fit bronze instead of mild steel handles). All English Moodys since about 1990 have those, and they also go into HR and Discoveries, but take care with used boats that a previous owner did not replace with something inferior. If you see "CR" or "DZR", replace them as Kenomac suggested. If there is nothing at all on them, then replace them fast.



You can buy new Maestrini through hull-fittings and ball valves from ASAP Supplies or SVB. You get a test certificate of the alloy composition with them. Order them at least a few days before the time you plan to install them, so you can enjoy fondling them a bit before they go into the boat

[deblen]

Originally Posted by Dockhead

As I wrote, the straight vs tapered thread issue is limited to the U.S. All through hull fittings and ball valves sold in Europe and, in fact, everywhere except the U.S., are BSP and compatible with each other.


How it is that incompatible NPT and NPS fittings got to be sold in the U.S., and apparently are still sold, must an interesting story, but I don't know it.

Thanks for clarifying that metallic ball valves are available in UK in BPS straight thread. Using a BPS mushroom head thru hull skin fitting,with a locking nut, & threaded fully into a BPS valve,fitting,would seem to be reasonably safe.
Much safer than us trying to thread NPS thru hull into a NPT valve or fitting. AFAIK,marine grade NPS valves,fittings are not available. I could be wrong. / Len

[Dockhead]

Originally Posted by deblen

. . .AFAIK,marine grade NPS valves,fittings are not available. I could be wrong. / Len

I think you're right about that. Groco makes an adapter, though.

[Dougtiff]

GROCO makes an adapter in various sizes to fit a NPT [USA] to a NPS [European].

[GordMay]

Originally Posted by Dockhead

... How it is that incompatible NPT and NPS fittings got to be sold in the U.S., and apparently are still sold, must an interesting story, but I don't know it.

Indeed.
See “History of standardization” ➥ https://en.wikipedia.org/wiki/Screw_...tandardization