epistosaurus – Thanks for the response, I’m really looking for some thoughtful input. My interest is not Forespar, Groco’s flange, the Spartan seacock style or ball valves, it’s about the “standards”. In particular, ABYC H-27 and UL 1121 “standards. Please note the quotation marks.
What does the “standard” say? Does it address the issues all of us boaters assume it does? To be honest, I don’t believe the ABYC, especially when it comes to thru-hulls and seacocks, has done the boating
public a service
But that’s another story.
Let me get to your point about Forespar’s data tables, in particular the comparison table and the ABYC/ISO tables presented by Forespar.
1. The first time I saw the Forespar Marelon/ABYC/ISO table (see attached) was back in 2002. The first time I saw the Forespar materials comparison was probably in 2007. By the way, you aren’t the first to be fooled by the chart (more on that later), I have seen it quoted/attached to many comments on this topic on this and other forums
for many years. The fact is, for the last 7 plus years Forespar has not removed that false information. Both tables are on the Forespar website:
Marelon ABYC & ISO
Click on “Marelon® Superior vs. Other Materials Comparison Chart” to see the comparison chart and “Marelon® Exceeds ABYC & ISO Standards” to see the actual values for Marelon, (for some reason I can not get the later chart to load all the time). As you’ve noted the comparison chart shows significantly higher values. I’m also attaching PDF of both these charts
At the end of March 2013 I emailed Forespar asking them which sets of numbers was accurate values for Marelon, the comparison table values (tensile strength (27,000psi and flexural modulus 1,300,000psi) or the ABYC/ISO table values (tensile strength (17,000psi) and flexural modulus (700,000psi.) Forespar responded by sending me the ABYC values tables were correct and provided the following attachment. So I can comfortably say that all products made before March 2013 have a tensile strength 17,000psi and flexural modulus 700,000psi.
I can further state that the comparison table Marelon values of 27,000psi and flexural modulus 1,300,000psi ARE NOT the values for the carbon fiber ball valves. I can further state that the comparison tables ARE the exact values for Dupont Zytel nylon 66 33% glass loaded 70G33L – BK. And that Marelon is, in fact, Dupont Zytel nylon 70G13L – BK.
I’m attaching the Dupont Zytel data sheet that has both 70G13L and 70G33L the material characteristics. Also, please note that on both tensile strength and flexural modulus you will see 3 sets of values:
DAM = Dry as molded. The test part is tested shortly after its molded
50% RH = 50% relative humidity. A test done on the part at 50% humidity.
100% RH = 100% relative humidity. A test done when the part is fully water
This is due to the fact that nylon is hydroscopic and degrades in water.
2. At this time I don’t know the exact composition of the carbon fiber ball valves. What I can tell you is that:
a. They are very new, and represent only 3 models of the regular 93 ball valve. Probably, less than 1% of Forespars valve sales.
b. And probably less than .01% of the ball valves in use or in stock.
c. The carbon fiber ball valves are threaded to ASTM standards, so the thicker 93 thru-hulls WILL NOT fit. Only bronze or Stainless steel
or the thin walled Marelon thru-hulls (nnnnnnnnnnn) can be used.
d. Forespar has not seen fit to provide the tensile strength and flexural modulus values for it.
e. They aren’t the values in the comparison table.
f. If you look at the Forespar site (xxxxxxxxxx) you will see a display that says “CARBON REINFORCED” (I've attached the actual page) and displays a group of Forespar plumbing parts
. None of those parts
are “CARBON FIBER REINFORCED.” I believe Forespar can truthfully state that all the black parts on the page ARE “CARBON REINFORCED” although the “REINFORCED” might be a stretch. If I’m not mistaken, DUPONT uses “CARBON BLACK” to produce the black color. If it has any reinforcing value it's miniscule.
g. Carbon fiber is simply a filler, it’s the resin that really critical.
There’s more. But give this some thought. And please respond with questions, issues, conflicts in anything I’ve said.