I’m about to start on a 14 ft x 27 x 5 race SUP. I’d like to shape from 1.0 lb EPS, no stringer, glassed with 2 layers 6.0 oz top and bottom. No bagging.
Will it buckle using this construction? It will be used for off shore ocean racing in strong wind and big swell. I will avoid breaking surf, as that will certainly snap it.
The shear size has me puzzled by what I can get away with. By the way, adding weight = slow race board, so I don’t want to beef it up if I don’t have to.
Thanks,
1lb, stringerless at that density is going to need more than 2x6oz, imo.
it’s going to be soft underfoot and it’s going to chatter without enough rigidity…that’s lost energy.
Hey! We forgot the ‘‘welcome to Swaylock’s’’, Dwight! And this is where it get’s swaylock-y, you first said stringerless and hand-lammed, just asking what lam schedule? That’s why I advised the uni-carbon; most stiffness per unit added weight. If you open up to other possibilities you’ll get enough suggestions on here to thoroughly confuse you. But the advice so far has been solid. If you can stringer the blank that’s the easiest and cheapest way to get stiffness in a hand-lam… It’ll make it easier to shape if you’re inexperienced. But I’d rather put that weight in the skin reinforcement where it can do double duty. Although GL will probably kill me for this, you CAN do the veneer (for a one-off) without vac; guys on here used bags of sand, tape, water balloons, and who-knows-what else to glue down skins. Then you hand-lam over, so it’s back to simple. Greg will come back on here to get me, and give you some good advice.
Yeah 5" thick is pretty average for race boards. Most dig the deck out a little to lower the CG and improve stabilty for the paddler.
I’m ordering a large block 1# EPS and hot wiring my blank out.
Standard layup for 1# is double 6 bottom triple 6 deck. To save weight use 6 oz carbon and do a carbon bottom and a 6 carbon with a 6 oz glass on the deck. Even with the carbon or the triple glass on the deck the board will still come out a little soft so count on that. 1# does spring back though so dents will magically disappear over night. Eventually the 1# does break down and begin to fall apart but it does hold up for a while and is pretty magic while it’s there.
GL and afoaf are right, 2 x 6oz both sides won’t be enough to yield the stiffness you need. If you’re set on no bagging, I’d suggest a uni carbon deck patch. It doesn’t need to be the full 14’ or the full width of the deck, either. A very effective stiffener with minimal weight penalty. I’m assuming you’re not worried about long-term durability, just something that’ll race well. If you’re in the tropics you may need to paint over the carbon to avoid thermal issues. Plus that way no one will know what’s in your secret weapon.
I also completely agree with these prior posts … At least one full layer of carbon on the bottom wrapping around the rails with a a layer of 6oz cloth over the top of that. I might go with two full 6oz. top with a 6oz. deck where your going to be standing and point loading the 1 lb. EPS … better put your fin/s boxes in with higher density urethane foam inserts surrounding the boxes to be safe. I’ve shaped hundreds of rescue and Bud Light series racing paddle boards since the early eighties, and have a carbon bottom racing paddle board entering the up coming Catalina crossing in August … Stiff as hell … Light as hell … Your shape might include a fine entry at the bow/nose … have fun …!!
Maybe I should bend on that one.
I’m just trying to reduce my workload and cost. Not sure how “into” racing I really am. Just want to build one and try racing.
Could I skip the carbon if I bag it?
Thanks everyone.
you’ll still want the carbon or some other means of stiffening the board up, regardless of whether you bag or not.
the bag gives you the option of using a “horizontal stringer”…a big flat stringer in the form of veneer on the deck to give you more resiliency underfoot and stiffness through the length.
it also gives you the ability to use additional bagging materials and lighter resin ratios to yield a tigther, lighter lam with more cloth, but conceivably comprable weights.
don’t go and blow a bunch of money on a pump and bagging materials just for this project (unless you were looking for a good excuse to do just that)…you could achieve your goals of simple and cheap by stringering the SUP and using a deck patch for 3x6oz on the deck.
whatever you decide to do, POST PICTURES!!!
Hey Dwight, do race SUPs typically run 5" thick? Also, what blank are you going with?
Thanks. I’ve been lurking for about a year.
Just had a thought, I’ll bet everyone might not be aware that all SUPs have 1/4 thick EVA deck pads. That has to help the deck against foot impressions.
Oh by the way … won’t matter if it’s the stiffest board in the world … if your rocker is wrong … your plowing water … if your outline isn’t thoughtful … it will be sucking you backward … If your center of gravity is to forward or backward … you’ll be watching ! … Now’s the time to observe and calibrate … check out some of the recent (water flow and release) posts that been flowing recently … Have Fun …!!
Hi Dwight -
Here is a “Standupzone.com” link to a fascinating build by Bill Foote.
http://www.standupzone.com/forum/index.php?topic=2141.0
I’ve been told that a “framework” of strategically placed carbon uni tape can stiffen and strengthen a board. Under the feet is where want to beef it up although you’ve already mentioned that a pad will help out there.
From what I know the rails are a good place to add extra reinforcement be it carbon or glass. It gets back to the old “glass around a cardboard tube” experiments.
You’re referring to the deck’s stick on grip pad? Are you going to use a large 3/4 or 2/3 length pad when racing or could you get away with a smaller more strategically placed pad because you are not walking/surfing the board?
I know the stand up zone well. I’m a regular on there. My zoner name is DW. Unfortunately Swayloks rejected my request for user name DW.
A little zoner history. I had some contact with Sam Pa’e and Dave Parmenter over this project. Dave suggested I use 1 lb EPS for ease of shaping, especially for a rookie. Sam glassed his 14 ft race board blank (1 lb EPS shaped by Dave) under his carport using 2 layers of 6 oz top and bottom, all vacuum bagged. But, I was a little concerned the construction was marginal. For such a huge board, without stringers, sandwich, or carbon, it scared me.
It sounds like a little carbon would make me feel better about my board.
Hi Dwight -
You have access to some keen expertise. If anyone knows, those guys do.
The uni carbon framework was passed to me via Stuey - the guy in Australia who designs and builds the Penetrator. That one is another fascinating design.
There appears to be some discussion over the flat rockered sharp entry vee bows (think prone paddleboard/kayak style) vs the concave or planing nose (more like conventional surfboard.) I guess it depends on the conditions in which the boards will be ridden.
Another excuse for a quiver!
I can understand why there’s some ‘‘discussion’’ over bow shape. When you’re talking about racing these boards without really surfing them, you just left the world of surfboard dynamics and entered the world of paddle-powered semi-planing small boats. Plumb bows work pretty good there. I doubt you’ll see them on surfboards anytime soon.
I had the opportunity to ride Sam’s 14’ Votice and I didn’t break it with my 220 lbs on it. Also,I have ridden many of Sam’s other boards, almost all are 1lb foam and stringerless with similar glassing, If your nervous about going that route then I would suggest the carbon glassing schedule that Mike Daniel mentioned previously.
I struggled with the same decision. I wanted the planing hull to win. I don’t want to paddle something looking like a boat. Now that the Maui crew are reporting the displacement hull is maxing out in large swells and feeling slow, I have another reason to stick with a planing hull shape.
I’m mapping several windsurf rockers now to help me develop where I want to take my rocker.