Jeff, you know of no boat company that used vacuum bagging? Don't take that "bag" reference too literally. The SCRIMP process is consistent and repeatable—ideal for one-design boat building." SCRIMP stands for Seemann Composite Resin Infusion Molding Process. It is a closed, vacuum-assisted, resin-transfer molding (VARTM) process used for the fabrication of fiberglass products.
"In the early 1990s TPI was forced to revisit the vacuum system—by the EPA. "At that time we were one of the biggest emitters of VOC's (volatile organic compounds) in the state. We had been trying for some time to develop the vacuum technology, but were still working with the resin outside of the bag. A salesman from Dupont suggested we talk to Bill Seemann who had been successful in developing a closed vacuum system. I took one look and said "you got it!" - Neil Tillotson.
The early 90's. Boat company. EPA. VOC's. You been asleep Jeff?
Note, that's Neil Tollotson, not me, talking. I'm making allowances that the Oracle of Jeff knows that name.
Since 1993, TPI Composites has established itself as a pioneer in the use of the process to build, among other things, buses, wind generator blades, SwimEx hydrotherapy pools and, of course, J/Boats. The advantages of SCRIMP "are huge," explained Jono Billings. "The fiber content of the laminate with the SCRIMP process is 70% by weight to 30% resin, with less than 1% trapped air spaces." In the world of balsa cored fiberglass boat building this is an important factor because by filling those spaces with resin you eliminate the ability for water to travel through the hull.
Is that what you were talking about? Thank you SOOOOO much for "explaining it to me." While I do recall your mentioning of the insurance study in years past, it was, I'm sure, buried in the page and a half reply to some simple question (yes, simple). Sometimes you just have to say yes or no. A dissertation just is not appropriate, and while YOU may have been discussing it, this was not due to me making any statement related to fiber length. Certainly nothing comes to memory. I have disagreed with you on strength issues, but I don't remember ever debating fiber length of woven roving.
However, if 2 ft lengths of woven roving are weak, that is a serious indictment against the (better according to you) current methods of construction that include the use of 1-2 inch fiberglass fragments in the chaos factor chopper gun technique. You cite an ancient study, but have yet to address the chopper gun angle and how it relates (newer is better?). You seriously cite an insurance agency-funded study? No bias there, huh? Riiiiiight.
So they didn't know how to handle fiberglass back in the 60's? Really. You cited the fiberglass strength myth, and I agree. They knew exactly how strong it was. They had to know. Weight being at a premium in aircraft (radomes) demanded they know exactly how strong it needed to be, and what thickness/composition was necessary. You also cite all the money the military invested in the development of fiberglass. All that, and they didn't know how to handle it? Or did they just keep that info Top Secret from the sailboat guys for over 15 years? Just last night I saw bags of folded woven roving in the auto section of Wally's. Wonder if they know they're selling an improperly packaged product that is weakening as it sits there? Agreed, wet out is more of an issue with woven roving. That's why you can't just come in off the street and do it correctly. That would seem to be an argument that when done properly, it's strong, and an unskilled worker is the issue, not the construction. I would think the report you cite would serve to encourage longer strands, not shorter as is currently seen, and better wet out techniques, not abandoning of the technique. Seems to me 2 ft sections are still stronger in old boast than chopper gun assembly in new boats. And if chopper gun construction is so good, a few fractured fibers in woven roving aren't an issue because they're still much longer than chopped strands.....but then, that'd tend to invalidate the insurance study, wouldn't it? Oh, but there's better wet out in chopper gun application, right? There's NO structural strength in chopper gun applications.
I do have a link some may be interested in reviewing.
Fiberglass strength for ocean sailboats
Some will say this fellow has a bias towards building blue water boats as strongly as possible. Yeah, terrible isn't he?
All this because someone wanted to know which of two examples would be more comfortable. I may have missed one along the way, but I'm thinking I'm the only one to actually cast an opinion on that actual question and the cited examples. Yeah, yeah, I'm the pariah because my attitude is so acerbic, but to me, Jeff comes across as condescending. It's an imperfect world.