Reviewing this thread of late last year, I agree…Surfteach gives an insightful discourse about how producing (or attempting to) 3 lb. EPS has its inherent challenges and IMO a point of diminishing return.
It may be well enough to say let the two different approaches to making surfboard blanks stand on their individual merits. The virign 2 lb. EPS that I have been using recently nets an extremely strong performance board using a 6/4 glassing schedule on both top and bottom. The material shapes well and the reduced hull weight allows you to focus the strength into the skin. Using a double layered top and bottom with ALL layers lapped onto the rails produces an extremely durable product for the consumer in a lightweight category.
I recently have spent time with White Hot Foam discussing different aspects of their specially produced “Surf Specific” EPS. This is EPS foam that undergoes a separate curing that they developed in their Arizona plant. White Hot is a subsidiary of a much larger company that supplies the housing industry, and the EPS that they produce for architectural features such as columns, baseboard, crown mouldings, and SIP’s, are an entirely different formulation of EPS similar to what some of us used throughout the 80’s on sailboards and some surfboards. A primary supplier of that particular EPS was secured, for the most part, from Western Insulfoam.
Regardless of who produces it, the difference with “virgin” EPS is that you are not geting recycled material. Some people might feel there is nothing too complex about developing and producing quality Expandable Polystyrene, but nothing could be further from the truth. There are also many misconceptions surrounding EPS as a material and it is noteworthy when informed individuals like SurfTeach, Greg Loehr, Mike Daniels, Otay, and others chime in with insights of their experiences with the material and its evolution of a period now spanning decades.
The age old complaint I hear from surfers that do not like the ride is the difference in bouyancy that is inherent to the material itself. I would guesstimate that the 1.0 or 1.5 lb. “styrofoam” (trade name originated by Dow in, or around, the 50’s) floated about 62 lbs. per cubic ft. back then. I don’t know what he calculation would be now or how or if it significantly differs with today’s improvements to ‘superfusing’ the material thru the use of IDRO/EDRO or other proprietary methods.
White Hot decided to stay with the large billet/bun production after researching results of smaller individual molds similar to what Marko is using. Each to their own on that matter. White Hot’s “SS” true 2 lb. foam has a noticeably crisper feel to the EPS beads due to a secondary curing process they developed for surf blanks. I also have two 2.5 lb. foam blanks from them that I am glassing with two different glassing configurations while weighing them at every juncture along the way to being finished. This is something I did with a Mowses Ice Nine blank last year. I originally began doing this back in the 1980’s while using the method to determine where and how much weight was added in production of high performance custom sailboards. It is a real eye opener to say the least.
The point I want to make here toward the possiblity of using higher density EPS (in this case, 2.5 lb.) is that the complaint from some surfboard manufacturers is that EPS requires sealing, use of epoxy, and the added cost of yardage in that EPS blanks are assumed to require double layers of fiberglass on the bottom as well as the top. With the use of higher density EPS, this may not be the case.The generally accepted approach toglassing EPS is subject to review with the development of newer epoxies exhibiting improved qualities from what we were familiar with in the 80’s…and as to the feel of the end product, good designers can use as yet disclosed methods to tweak the ride in a multitude of ways.( I’m staying mum on my own current R&D…).
No doubt people have their individual preferences and agendas for whatever reason. The point is, there are attributes from each core material that is currently in use, and IMHO, it is pointless for one to begin mimicking the other…
