I really appreciate your response, you’re absolutely correct in asking for verification re. what I’ve written on this thread. Just like you, this information challenged my assumptions of marine products and the ABYC. I’ll have more on the ABYC at a later time.
By the numbers.
1. Please hold off on the purchase of a Forespar seacock, I think I can show you enough evidence to convince you about Marelon and Dupont Zytel nylon strength loss and moisture absorption. However, if you’re purchasing a ¾” Forespar 93 flanged valve to service an existing function that requires a ¾” flow rate you will need to go up to the 1 1/4” size. The reason is that the 93 series thru-hulls are a really odd ball size, unique to the 93 only. The ½ and ¾” utilize the same thru-hull so the ¾” ID .62” is undersized. A normal thru-hull calls for an ID of around .70”. The Forespar 251 thru-hull ID for the 849 flanged seacock is .69”. You would have to go up to the 1 ¼” if the requirement called for a full .70” ID flow capacity.
This info can be found on pg. 41 of the Forespar catalog.
2. It would take several months to fully saturate the seacock. Additionally, the rate of saturation increases at a decreasing rate over time. So it might reach 80% saturation in 3 weeks and the last 20% might take 6 weeks. This is also info available from Dupont.
3. Regarding the carbon fiber issue. First, you really need to watch the video, at least the first 50 seconds. I just tried loading the video and for some strange reason it’s not available. Luckily, it is still on Youtube
or on Youtube Wes Gary why marelon?
If for some reason it’s taken off Youtube all I can do is quote the basics of what Wes Gary said.
Wes Gary comes on holding a Foresar 849 flanged valve and he says,
“HI, I’m Wes Gary, I’ve (done this, that etc,...........)
“I know polymer composites very well.
“I’m here to talk to you about Forespar’s plumbing fittings. I know that Marelon is not just a plastic, but an engineered carbon fiber and glass reinforced composite polymer ideally formulated for marine use?”
Forespar did, for a short time, make a limited batch of 93 series ball valves made from carbon fiber. But, according to Forespar they abandoned that project long ago. And as I can prove, Marelon is simply Dupont Zytel 70G13L 13% glass filled nylon.
Also, Gary states that, “Marelon is the only plastic that meets the rigorous ABYC standards.”
This is simply not true. There are at least 24 plus plastics that I know of that meet and exceed the ABYC standard.
It’s important to note that this is a closely scripted, paid, advertising video, not just an amateur video. Also, here is a Forespar document that shows several items under the heading “Carbon Reinforced.” Again this is all scripted to present an image of innovation and strength.
a. Note that the word FIBER is omitted.
b. I can say comfortably that NONE of the products presented in that picture are or ever were made of “carbon fiber” and that’s according to Forespar. I have the email to prove it.
c. Interestingly, the black products might have carbon in them, “CARBON BLACK” that is, to create the black/UV resistant color. But that carbon is not for strength, and may even decrease the material strength slightly.
I cannot sent the Carbon reinforced document via Sailnet, it's simply too big. If you want to send
me your email in a private message I'll be happy to send you all three documents I have for you.
4. On page 32 of the Forespar Catalog, you’ll see a table Forespar uses to suggest that Marelon is a close second to bronze. However, the tensile strength and flexural modulus values presented there are for Dupont’s Zytel 70G33l 33% glass filled nylon. How do I know? It’s the material we tried using for the original molding. Marelon is Dupont Zytel 70G13L 13% glass filled nylon (more on that later) and we wanted to use a stronger material. On pg 33 of the Forespar Catalog you'll see Forespar's values for the real Marelon. Compare the two sets of numbers. This was no mistake, it's been out there for years, and they've known about it.
I’m also including the Dupont table for all the 70 series Zytel products. You’ll see that both sets of Forespar’s values for Marelon co-inside with the Dupont numbers. There’s no need to test them, Dupont has already done that, and it’s their testing equipment and their product so they will always want the better values. Remember tensile strength and flexural modulus are the defined ABYC testing characteristics. You can do the exact loss percentages at saturation, my 60% was a rounded value. The actual values are: Tensile strength 57.1% loss and Flexural Modulus 64.3% loss at full saturation.
Again, I cannot sent the Dupont Zytel document via Sailnet, it's simply too big. If you want to send me your email in a private message I'll be happy to send you all three documents I have for you.
Additionally, I’m providing you with a document that Forespar provided UL when they were testing the 93. You will see the Dupont 70C13L very clearly referenced, along with the thru-hull fitting material 8018 WT listed. This is a new form of Marelon, that has less strength than the “original” Marelon listed in Forespar’s literature.
Again, I cannot sent the Forespar document via Sailnet, it's simply too big. If you want to send me your email in a private message I'll be happy to send you all three documents I have for you.
I hope this is of interest. If anyone want the unattachable files please send me a private email with your email address and I'll send the info out. I can assure you it is as I as I represented it.