I suspect Greg Loehr will have a straight forward answer for me but maybe someone else will have some good advise as well. I have a 8’3" 13.5"x 21.75"x15.125"x3.0" in the Freeline factory that John Mel shaped for me. I don’t know if it’ll be glassed with epxoy or ploy. But I’m going to lobby for an epoxy job when I receive the Resin Research product. So here’s the question. I was going to wrap it with double 4oz. and put a 6oz tail patch on it where I stand if it’s done with polyester. I don’t mind a little extra weight. I take pretty good care of my boards so I’d like them to be more durable that a 4oz bottom and 4/6oz deck would be. I have one that’s glassed this way and the deck looks like the luna surface. If I glass it with epoxy what would be a good glass schedule to use that would give me a similar strength to the one above? I’m completely open to any suggestions. Mahalo, Rich
Using epoxy you could add and other 2 oz of glass to the bottom and possibly another 2 to 4 ounces of glass to the deck and end up at about the same weight as you will with the schedule you have planned right now. The complaint about the deck caving will be obviously better with the extra glass. But if you replaced one of the layers on the deck with a layer of 6 oz carbon inlayed it wouldn’t dent at all. And be the same weight. I’m doing a board right now with a 2 oz. Syntech bottom (it’s a synthetic fabric) with a 4 oz. glass over that, both layers laped and trimmed. This will be done with 2020 resin which is the more flexible resin we do. This will provide 3-4 times the impact strength on the bottom. Then on the deck I’m inlaying a 6 oz carbon with a 4 oz. layer of glass over that. The carbon layer is a 4 harness satin weave which will take significantly less resin (lighter) and be super strong. Also I’m using our 2000 resin for the deck. This shouldn’t dent at all. This is with a 1.5 lb. blank which is VERY light and also the foam will have memory at this weight so any dents I do get should go away. So the goal is a bottom that won’t ding (Syntech) and a deck that won’t dent (carbon). By the way, for denting, one layer of 6 oz. carbon is equal to two layers of 6 oz. glass. This should be extremely light and tough.
What about making an eps blank with a layer of higher density foam (better compressive strength) on the deck and lower density foam underneath (more bouyancy). Say if you went 50/50 - When you shaped the deck you’d end up with the lower density foam in the rails of the deck but you could have wide laps on top to strenghten the rails or you could have a flatter deck. You’d have to calculate the bouyancy for both densities and figure out the total bouyancy based on the proportions you use so you could get the right total thickness. You could glue the layers together with a mix of filler (glass ballons or whatever) and epoxy so the join was easier to shape. What do the panel of swaylocks experts think the pro’s and cons of doing this would be?
Greg, Carbon? The black weaved stuff that costs a fortune? The lightest carbon weave I can buy here is 3.7oz and it costs over $25.00 a yard last I checked. I don’t want a black board so maybe I’m not hip to something your addressing here. Sounds like the glass schedule I mentioned will be ok if I use the 2020 resin and hot coat with a double shot of additive “F”. How well will it polish out? Off to check the beach breaks – Rich
After making sandwich sailboards and thousands of epoxy surfboards, both sandwiched and not, I’d have to say that in my experience surfboards should not be sandwiched. I’ve found that they ride better without a high density foam under the laminate and that it’s not stucturally called for. I’ve had many people say that they don’t care for the ride of the molded products on the market. I personally think they are just too far away from the flex characteristics surfboards have evolved with. That doesn’t mean that in the future there might not be some comprimise that will change things. But for now the best boards, in my estimation are non sandwiched lightweight custom epoxies. Rich, Watch the price of carbon tumble in the coming years. I know the black color must be delt with but if you want to stop the decks from denting, this is the product that does it. The cost of running 6 oz. carbon on a deck inlay for 9’ is about $30 right now. Used to be $100. Anyone interested in carbon cloth should contact Graphite Master in LA or go to their website, www.graphitemaster.com
My post probably wasn’t that clear - I meant something like the pic below. I thought maybe you’d get a deck more resistant to pressure dings, also because the denser foam should be more resistant to compression, your board would spring back quicker when it flexed - especially if you had the polyester fabric on the bottom. Which I understand is more more resistant to tension. 
I did understand what you meant. I’ve built boards exactly that way. Every one broke. The reason is that the deck foam is stiffer than the bottom foam. Whenever the deck goes into tension all the force is transferred to the bottom which is then in compression. The bottom then delaminates from the lighter foam and a break occurs. At this point in time, for custom boards, carbon fiber fabrics are the way to eliminate denting. Bamboo veneer and some other wood veneers are also a possibility. There is also a material called Coremat which might be usable. I’m going to Hatteras in a couple weeks to try some new stuff. Denting has always been a challenge because of the low density foams used in surfboards but I beleive a lightweight solution is out there. Aluminum is another possibility. By the way I like your illustration.
Right, I was only thinking about what happens when you are riding - not what would happen when the thing flipped over and got hit by the lip. Being dynamically biased to force from one direction made would make it vunerable to force from the other. Anyway with the lower weight of the eps you’ve got much more leeway for different glassing schedules. Check the latest Australian Surfing Life - there’s a story about aluminium veneered boards - people seem to like 'em, not much about how they’re made though.
Someone beat me to my idea? Damn. I’ve been planning this aluminum thing for a while. What did they say? And comments on denting? I don’t have an outlet for that mag here. I know that the Aussies were doing a lot of veneer decks a few years ago. Called them “timber” decks. We do have some new techniques for applying sheets of different materials to the foam so I am quite interested in these types of materials.
Greg, Here are the pertainent points from the article. “aluminium veneer,0.5 mm thick, vacuum formed over a stryrofoam core” “Burliegh shaper Dick Van Straalen has been helping develop the things, along with their inventer, Ron Haystead” “Dick reckons …,marginally heavier, less labour intensive and potentially cheaper than a regular board” “‘they all say it slices’ says Dick” “Dave Rostovich has had a little pocket rocket number and loves it” “'it’s changed people’s perspective on what flex is in surfboards’Says Dick ‘Because these are stiffer, everyone says how much speed they generate’” “…with a standard polyurethane core they were coming out too heavy. When he” (Ron Hasted) " contacted a styrofoam supplier, they put him on to Dick, who has been using styrofoam for years." “the boards require no sanding top and bottom, just a bit of finishing around the rails…” There’s a picture of a guy riding one, looks like shiny aluminium with what look like lap lines on the deck. Feral Dave may know more about these.
Ive seen the future and it is thermal plastics. Holly Sheep turds. Will someone direct me to a 2 lb foam that can take 450 F. I don’t know if the technology can cross over to surfboards, but if it can, look out. In reality, my boards hold up pretty well, so I don’t think I will be going to Aluminum anytime soon. Sluggo
But Dick says, “That these are stiffer”. Everybody says that! … have fun
I thought everyone said “these new boards are flexier”
Just came across Dick’s site: http://www.dickvanstraalen.com nothing about the “tinnies” here, but there’s a bit about the fish of David Rastavitch’s that impressed Fishfingers in the post further up.