Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 17-05-2013, 18:10   #76
Registered User
 
Watercolor's Avatar

Join Date: Sep 2009
Location: Montpelier, VT
Boat: On the hard for now - 2 dinghies
Posts: 198
Re: Marelon seacock failure

Ron,

Let's try it a different way.

Your question "They are ABYC and USCG approved though, right?"

My response is simply, only the 93 is ABYC and UL approved. but:

Forespar states clearly in several documents that Marelon is Dupont Zytel 70G13L- BK nylon. Dupont has data tables that show that their "Marelon" in a marine environment has a TS of 7.500psi and an Fm of 250,000psi. The ABYC material standard is TS 10,900psi and FM 500,000psi. Additionally, PVC does not meet the H-27 materials standard, yet in the marine environment our boats reside is stronger than Marelon.

These are all documented facts.

In a marine environment Marelon does not meet the ABYC standard and is not a s strong as PVC according to Dupont.

That's a fact.

I'd love to here some comments. I can't think of anything more important on a boat than a below the water line thru-hull and seacock.

I'd really appreciate knowing what people on the forum feel is important in a thru-hull and seacock. I think it's important that the users of these devices really speak up.
__________________

__________________
Watercolor is offline   Reply With Quote
Old 17-05-2013, 18:58   #77
Registered User
 
Cotemar's Avatar

Join Date: Dec 2007
Boat: FP, Helia 44 Evo
Posts: 5,717
Re: Marelon seacock failure

All I can say is that I have used the Marelon thru hulls with great results and no issues. I have also replaced my head hoses with PVC pipe that also worked great with no issues.
__________________

__________________
Cotemar is offline   Reply With Quote
Old 17-05-2013, 19:34   #78
cruiser

Join Date: Feb 2008
Location: North Charleston, SC
Boat: Camano Troll
Posts: 4,669
Re: Marelon seacock failure

Quote:
Originally Posted by Watercolor View Post
................. In a marine environment Marelon does not meet the ABYC standard and is not a s strong as PVC according to Dupont. ..............
You're going to take that up with the ABYC.

It's hard for me to believe you know more about this than the ABYC folks regardless of what you post and what you claim is "a fact".

If you can get them to rescind their approval, post it here. Then I will believe it.
__________________
rwidman is offline   Reply With Quote
Old 17-05-2013, 19:39   #79
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by rwidman View Post

You're going to take that up with the ABYC.

It's hard for me to believe you know more about this than the ABYC folks regardless of what you post and what you claim is "a fact".

If you can get them to rescind their approval, post it here. Then I will believe it.
ABYC doesn't approve anything. All they do is give some guidelines and they mess up often, or are lagging behind for years. Don't mistake them for the all knowing thruth.

In this case I believe that the 500 pound statis test is for a dry thru-hull + seacock. I think Marelon passes that test but fails when submerged for a couple of days. That clouds things a bit, right?
__________________
s/v Jedi is offline   Reply With Quote
Old 17-05-2013, 20:52   #80
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 3,064
Re: Marelon seacock failure

Quote:
Originally Posted by s/v Jedi View Post
ABYC doesn't approve anything. All they do is give some guidelines and they mess up often, or are lagging behind for years. Don't mistake them for the all knowing thruth.
Here's a case in point. The AquaSignal Series 25 navigation lights are USCG and ABYC approved. Heck it's embossed right on the product.

Yet the ABYC E-11 standards specifically say screws shall not press directly onto wire strands, a pretty basic rule. .. These fixtures do not have pressure plates and the screws grind directly into the wires strands, as installed, in every installation I have ever seen..

I have had numerous cases of no nav lights where this problem was the direct cause and one as recently as three weeks ago where the wires fractured at the set screw after being molested & destroyed by the set screw..

"11.14.5.1

Wiring connections shall be designed and installed to make mechanical and electrical joints without damage to the conductors.


11.14.5.5

Connections may be made using a set-screw pressure type conductor connector, providing a means is used to prevent the set-screw from bearing directly on the conductor strands."

So AquaSignal does not supply a pressure plate in the fixture nor do they provide crimp on wire ferrules with the nav light but the device meets ABYC standards???

Problem is unless someone brings this to the attention of the ABYC they simply don't know. IMHO the AS series 25's should ship from the factory with a "pressure plate" because NO ONE installs them properly.. They just stick the stripped wire in the hole and tighten the set screw and mash and destroy the wire. Some Euro strips come with a built in pressure plate but most don't.

Technically the Aquasignal Series 25's do not meet the standards unless the installer used crimp on wire ferrules to keep the set screw from bearing directly on the wire.. In many years of doing this I have never once seen anyone other than myself do an ABYC compliant installation of the Aquasignal Series 25's... Not one builder or installer. Perhaps there are a few installations out there done correctly but I have yet to see one...

This is one of the most common nav lights on the market with perhaps hundreds of thousands of installations and the vast majority never, ever met the ABYC standards as installed.....


Here's an example that completely lacks any standard!!


While not a "standard" (yet) why do we allow marine domestic hot water heaters to be connected directly to an engine via a heat exchanger where domestic water temps can potentially reach 180+ F? Why do we continue to allow these installations without a thermostatic tempering valve??????

This would NEVER and is NOT allowed to happen on the mainland or in commercial plumbing but the industry has looked the other way while many get burned and scalded like my own nephew did in 2005 on a brand new 2005 vessel. This is 100% dangerous and cmpletely unacceptable that builders can ship boats in the US with domestic water heaters that have zero temp control limits other than what ever the engine is running at. Today many engines run at 180F - 200F. Where is that "safety standard"....

Please VOICE YOUR CONCERNS to the ABYC so they can act on this!!! NO water heater should ever able to reach 160F let alone 180-200F, and they do and can, if not properly installed yet we have no standard in place to deal with this.

Rant over.....
__________________
Marine How To Articles
Maine Sail is online now   Reply With Quote
Old 17-05-2013, 21:39   #81
Registered User
 
Watercolor's Avatar

Join Date: Sep 2009
Location: Montpelier, VT
Boat: On the hard for now - 2 dinghies
Posts: 198
Re: Marelon seacock failure

rwindman - Everything i've stated is a fact.

Cotemar - I know that there are boaters out there with 50 year old non-functional gate valved seacocks, who have never had a problem with them. I'm sure the same is true for the Groco seacocks that had corroded balls and stems who are still out there and will tell you they've never had a problem. There are quite a few boat owners with the 93 series, that like you never had a problem with their seacocks, until the latent problem they really had decided to make its presence known.

Everythng! These aren't claims, they are indeed facts.

Nine years ago I thought Marelon (AKA Dupont Zytel 70G13L) was the gold standard for marine plastics. Actually tried molding a marine fitting with the 70G13L (AKA Marelon.) I assumed that the ABYC knew what it was doing. It was a bad assumption.

I wasn't getting the precision out of the "Marelon" so another material was suggested, the material had virtually no mold shrink and worked perfectly. Before I dared re-do the molds I wanted to compare it with "Marelon" (the gold standard) for strength. The numbers I presented above are the correct values for Marelon (AKA Dupont Zytel) right off the data table.

Marelon does loose over 60% of it's tensile strength and flexural modulus within months of being immersed in water. Actually, in a marine environment Marelon will have loose 57% of its tensile strength and 64% of its flexural modulus. And those are the facts direct from Dupont and Forespar.

Actually, those aren't completely the facts, because I discovered only a year ago that according to Forespar, in their ABYC/UL documentation, there appear to be not one but TWO "Marelons." The thru-hulls accordng to Forespar are made of a different Dupont nylon material called Dupont 8018. Yes, TWO Marelons.

The thru-hull 8018 Marelon has a tensile strength of 12,900psi and a flexural modulus of 530,000psi and will loose 55% of its tensile strength and 61% of its flexural modulus in a marine environment.

So I wasn't quite truthful. The Marelon 93 thru-hull, in a marine environment is only 81% as strong as PVC (tensile strength) and just over half (48%) as strong as PVC (flexural modulus.)

So how does the ABYC and Forespar get around these facts? As I've said before, somebody decided that the non-metal material used in thru-hulls and seacocks should be tested, "DRY AS MOLDED."

So here's a few WHY'S? for anyone reading this to ask themselves.

1. Why would you set a material standard for a critical below the waterline product as "DRY AS MOLDED?" I'll give you a hint, I asked ABYC this question, and I'm still asking it.

2. Why did Forespar make the 93 series thru-hull fittings oversized? And why didn't they do the same for the 849 series, the ones that you and I can buy?

3. The 93 series has 6 sizes, why did they make the thru-hulls non-standard so that if a boat owner wanted to replace the seacock/thru-hulls with bronze would have to re-glass the oversized holes for every odd sized (1,3,5) 93 series unit? By the way, the even sized units all have a diminished flow rate. For example, the 2" thru-hull only has the flow rate of the 1.5" unit.

4. Why do the 93 series handles fall off so easily? And why can the 93 series flood your boat once the handle has fallen off?

There's a lot more to this than I've mentioned here. I stumbled on to this, I feel, serious issue solely by chance as I said some years ago. I can't answer for the ABYC and why they did what they did, from what they've provided me for answers neither do they. So I've tried to provide some honest information on the issue.

I really would like some thoughtful responses to what I've presented. What is it you'd like to see regarding thru-hull and seacock characteristics?
__________________
Watercolor is offline   Reply With Quote
Old 17-05-2013, 22:09   #82
Registered User
 
Watercolor's Avatar

Join Date: Sep 2009
Location: Montpelier, VT
Boat: On the hard for now - 2 dinghies
Posts: 198
Re: Marelon seacock failure

Jedi - good point. The issue is, as you say, the standard is set "dry as molded." The problem is no one seems to know why it was set "dry as molded." We can speculate, but that's it.

Maine Sail - Feeling better after that "rant?" Actually, I'll pass the Aquasignal info on to Page, I think she installed on on our Shannon.

There are two problems going directly to ABYC.

1. Unless people are informed and do some research, even if it's only checking to see if my information is correct or valid. Look at the impact issue, all the experts talk about impact as being a major issue. You've had direct experience with that issue. I can list of quite a few. Yet, there is no impact test in the UL 1121 standard, none. The ABYC told me that the static load test is a surrogate for an impact test. I haven't talked to an engineer yet who accepts that premise. That's why a "static load test" is called a "static load test" not an impact test.

2. The new H-27 now considers a thru-hull and ball valve combination to be defined as a seacock. How did that happen?

3. I feel that it's important for the boating community to debate the issue regarding what is really important for thru-hull and seacock safety. For example, should thru the hull knot meters and depth sounders come under the aegis of H-27? Should impact be a critical piece of the testing? etc. Before going to the ABYC.

Your thoughts please?
__________________
Watercolor is offline   Reply With Quote
Old 18-05-2013, 00:19   #83
Registered User

Join Date: Apr 2010
Location: San Diego
Boat: Cheoy Lee Clipper 42
Posts: 19
Images: 1
Send a message via Yahoo to Wakuu Send a message via Skype™ to Wakuu
Re: Marelon seacock failure

Well, $H!T. I just replaced all 10 of my throughs with Marelon. Its been in the water a year and I've lubed them every 6 months, from the outside with no issues. None of them seem any stiffer than they were the day I installed them.

I read some one talk about impact.....I'm not sure about you guys, but all my throughs are WAY out of the way behind panels, etc. with the exception of one.

I see a lot of 10 yrs+ listed. One thing to note about mine, I got the ones that were "now carbon fiber reinforced" not sure if that makes a difference.

Guess I'll let you guys know the day I do have a problem.
__________________
Wakuu is offline   Reply With Quote
Old 18-05-2013, 02:10   #84
Moderator
 
Boracay's Avatar

Cruisers Forum Supporter

Join Date: Feb 2004
Location: Pelican Bay, Great Sandy National Park
Boat: Steel Roberts Offshore 44
Posts: 5,175
Images: 18
Re: Marelon seacock failure

Wakuu
I'm not going to hold my breath.
__________________
Rust never sleeps
Boracay Blog.
Boracay is offline   Reply With Quote
Old 18-05-2013, 04:16   #85
CF Adviser

Cruisers Forum Supporter

Join Date: Aug 2009
Boat: Custom Van De Stadt 47 Samoa
Posts: 3,755
Re: Marelon seacock failure

I have an aluminum hull and bronze is not an option so I have marleon seacocks (flanged).

Once I wanted to remove one. I thought I would be able to unbolt the flange and it would come loose by hand, but I could not get it loose (they are 'gasketed' down with 4200 to the mating aluminum flange, so I got out a small hammer and hit it. It did not come lose nor break. I then got out my small sledge hammer and hit it a couple times. Still did not come lose nor break. I tried hammering a paint scraper and a chisel under the flange but got nowhere. In the end I cut the thing off with a saw.

That suggested to me that the (1 1/2") marelon seacock bodies are pretty damn strong even 'wet'.

I don't have any experience with the thru hulls, as I use welded aluminum "pipes with flanges"
__________________
estarzinger is offline   Reply With Quote
Old 18-05-2013, 05:43   #86
cruiser

Join Date: Feb 2008
Location: North Charleston, SC
Boat: Camano Troll
Posts: 4,669
Re: Marelon seacock failure

Well, I don't have Marelon seacocks, I have bronze and I don't believe I'll be replacing them in the near future, but it's always interesting when a private individual or two hold themselves out as knowing better than the International standards organizations, whether it be boating or some other subject.

I've learned that there's no point arguing with these people, they have already made up their minds, yet it's fun sometimes to stir them up.

We have boaters posting who have Marelon seacocks and valves and for the most part, they are satisfied with them. They do have the advantage of being non-metallic so that keeps the owner out of the "bond or not bond" argument.

You guys carry on, it's pretty entertaining to read.
__________________
rwidman is offline   Reply With Quote
Old 18-05-2013, 05:51   #87
cruiser

Join Date: Feb 2008
Location: North Charleston, SC
Boat: Camano Troll
Posts: 4,669
Re: Marelon seacock failure

Quote:
Originally Posted by Watercolor View Post
............ I feel that it's important for the boating community to debate .............
Plenty of "debating" (another word for arguing) going on here, but nothing will ever get resolved. It's pretty much an issue of who is willing to type the most (or biggest) words and who can do the most cutting and pasting from the Internet.

It's entertaining, but in the end, nothing will change and the sun will go down tonight and come up tomorrow morning.
__________________
rwidman is offline   Reply With Quote
Old 18-05-2013, 06:49   #88
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: Marelon seacock failure

Like Evans, we have marelon valves and had to remove one (15yr old, entire life in water) once. We also have the thruhulls. Removing the thruhull was difficult because it was set with 5200 and would not pop out.

Hitting it will a dead blow hammer straight on the threaded inside part had no effect in either pushing it out the hull or damaging it in any way. A chisel and hammer on the outside flange served to make a few dents and cuts in the flange, but was not able to make any difference in removing it. After both these potentially destructive attempts, the thruhull could have been put back in service with no problem.

I ended up cutting it in pieces with a sawzall, and even then it was more resistant to damage than I expected. It cut with no problem (bronze would also), but unsticking the pieces from the 5200 required prybars, chisels, hammer, etc. These smaller pieces were highly resistant to deformation and damage as they were forced away from the 5200 holding them.

So I don't know about what tensile strength and flexural modulus they have, or even what numbers in those measurements I need or feel are minimal. However, I know I put more potential damage on those fittings than any reasonable use on our boat I can think of short of grinding them against a reef (where the thruhulls and valves would be the least of my problems).

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 18-05-2013, 11:54   #89
Registered User

Join Date: Mar 2013
Location: Belfast, ME
Boat: Beneteau 49
Posts: 82
Re: Marelon seacock failure

Would it help to add a zinc to each bronzish seacock inside the boat to eliminate the de-zincing of the fitting? (Bronzish because its a Beneteau)
__________________
Utahsailor is online now   Reply With Quote
Old 18-05-2013, 11:57   #90
Registered User

Join Date: Mar 2013
Location: Belfast, ME
Boat: Beneteau 49
Posts: 82
Re: Marelon seacock failure

rwidman: I've been on a couple of standards committees and have a much lower opinion of their quality. They were heavily populated by industry engineers who pushed their company's points of view...
__________________

__________________
Utahsailor is online now   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 11:40.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.