shaping is shaping - i use same tools for pu and eps - it just takes a little different touch with eps - you’ll figure it out just go for it
Shaping my one and only eps board was a chore, I didn’t like it. Seemed like a lot more work. I said not likely ever again. Then I rode the board - and I really like the way it rides. So now I’m like, ok, maybe…
I started shaping on Clark foam, about 20 boards, lam with pe then i move on eps epoxy because i have to Work quietly. Making my blank from blocks lam with Windsurf epoxy, i quickly like them more because : it cost less (for me), easy to have rocker and foil i want, no noise (Hotwire shape), no smell, more time to work, more durability (because i make them same weight as 44/4 pupe). What i didn’t like was sanding, but with right sanding tool and finish resin it’s cool now, and stiffness feel sometimes, but with right stringer and fiber no more a problem. I epoxy lam pu blanks récently and i found it a nightmare, réalise after 20 years of epoxy expériments i développe my one routine. So it’s just a question of feeling and practice.
Still oscillating between EPS and PU
The final straw…
Any advantage?
PU/PE is the easiest build process, and it’s fast. If you already use epoxy… shouldn’t be an issue. Just get a Marko superfused blank.
Going from poly resin to epoxy takes some getting used to. Epoxy cures at the rate the resin mix is set to. Each brand has a couple of choices, like slow or fast, but that’s all. With poly, you can add or subtract catalyst and change the curing time. You can also use UV and have a lot of time to mess with a lam, then flash it and it hardens real fast. Sanding epoxy resin is different, and getting a nice shiny finish with epoxy is harder compared to Poly.
For the weight/strength issue, I think stringerless EPS and a vacuum bagged skin wins. Carbon Fiber vacuum bagged over a light EPS core makes a really light but strong board. Same for 1/8" balsa sandwiched between 4oz fiberglass vacuum bagged over 1lb EPS. There’s a lot more work, but a lot less sanding and finishing.
But like I said earlier, I have not used newer PU foams, so I don’t know what they are like.
Main advantage of eps must be cost. Billet foam make correctly with right équipement (industrial fine grade) is at least same quality ( cohesion, uniformity, etc ) than surfblanks molded eps and far cheaper. Then you can preshape easily with hotwire. So you can spend more in lam: epoxy resin, more fiber, Time… If you have to pay same for an eps blank than for a pu one go with pu.
An eps epoxy board must have a lighter blank with a thicker lam and flexier stringer than a pupe one. Can ended in a normal Weight board, same as stock light pupe, durable (ding resistance) with a neutral flex feeling.
“If you have to pay same for an eps blank than for a pu one go with pu.”
“Then you can pre-shape easily with hotwire”
Agree
“Shaping my one and only eps board was a chore, I didn’t like it.”
AHAHAHAAAA… And purposely making your wooden boards in what is seemingly the most complicated manner possible isn’t a chore?!
The gases created are really toxic! I think I remember hearing something about cyanide(?)
Wait- John, are you telling us that burning toluene di-isocyanate polyurethane foam releases hydrogen cyanide, among other things?
Wikipedia says that too. Start with polyurethane, page down to health and safety, follow the links.
Has anyone mentioned eps sucking water? Exotherm problems when doing boxes, leash plugs? Just saying. Mike
EPS is full of problems. But some people like to ride it and buy it. There are short cuts. If you are serious about it; send a file to Marko and have them cut a Blank for you. Scrub it. Fin it and glass it. Otherwise for the time and trouble stick with those buckling US blanks. I use Millennium Yellow & Red or Artic Orange when I want lightweight boards. No snaps. No buckles.
Hot box before sand, eh? Okay, now I know your secret.
Wow!
Thank you all, for every word!
So at the moment I am thinking this…
I have checked out Marko and indeed some quality stuff.
The 6’-0” M thick or 6’-4” thick are close.
And USB’s “superfused” molded blanks are limited and again, just “close”
Not what I want for my first go at EPS.
My comfort zone with my foam has been USB.
To further enticement, USB says they will cut block EPS to any PU blank.
A 6-0R? That would be nice for my first go…
Hum, just seems like a lot more work.
It is just too bad the “molded” blanks are so limited for a fellow making 5-10 grovelers and step ups.
Damn it!
What 2 do?
A few and Lowell mentioned Artic orange.
Checked them out, seem like cool folk with nice product.
Having to do all the searching of these foam outfits, you maybe too young, well, it just reminds me of a time of Walker, Clark and Foss, before Clark’s death grip on the business…
Forgive my ramble…
I am left with, simply go to Artic and stay with my stinky stuff.
Or go with something new and challenging?
Fuck it!
I’m going to go fishing for a while…
The folks at USBlanks have a pretty good selection of molded EPS as do the folks at Marko. If you get acquainted with one of the design programs, Marko (and others) can machine one to a near finished blank for you. It would be easy to at least come up with a design that would be the equivalent of a ‘close tolerance’ blank that just needed some scrubbing. FoamEZ is able to order up pretty much any CNC cut for you if you have the file or the guys at Marko will usually deal direct.
I know of a guy who makes regular deliveries of blanks and boards if none of your local supply houses can help.
I had a USBlanks molded EPS blank that I won in a raffle at the Surfing Heritage Museum. No one was able to tell the difference between that and a Marko blank. An industry guy even wanted to argue the point… I.E. “DUDE - I’m telling you, that’s a Marko!” I had to show him the little USB logo on it.
Are you trying to get away from polyester resin, or??? I’ve also had a fairly well known industry guy insist that “You can’t use polyester on EPS and you can’t use epoxy on urethane.” Not true - well, 1/2 true. You can definitely use epoxy on urethane foam.
Anyway, you know how to shape as well as anyone around here. Mowing down a fat EPS blank shouldn’t be a big deal for you. Just give it a go.
Yep always sand fully cured epoxy. Lower toxicity risk, higher hardness easier to sand with right tools.
For those of you who might be interested; got
an email a couple of days ago and Artic is now offering
a limited catalog of EPS molded blanks. I’m going to
order a couple with my next batch and will post my
shaping comparison to Marko. I have a feeling I might
know who is molding these blanks for Artic in TJ…
I am liking the look of that blank.
Teach, pls do let us know your impressions of that molded blank. Thanks
Come on guys EPS is not scary. Just shape the Mother-fer. Get a 2lb blank from a reputable company, shape it, glass it, sand it, surf it.
- It takes 2 days to glass epoxy board because of cure times… A poly board takes 1 day.
- Poly boards sand out nicer with higher grits, Epoxy is denser and takes lower grits
- shaping poly is easier because the foam is buttery, EPS is chunky and rough
- Poly blanks are close tolerance, you can shape a board in 30 mins, just template, skin and glass. EPS is a slab cut, you need to actually shape to make a surfboard. EPS will make you into a surfboard shaper.
- a properly made EPS epoxy board will out live and surf a poly board. I have made them for old poly guys all the time…and the results are the same. EPS will take years off you performance surfing. But if you are a cruiser then it doesn’t really matter that much between the two.