Is 2# eps overkill in a compsand board?

General Discussion
1

I was recently discussing with some other swaylockians the details of a planned build I’m going to start on when the materials arrive. I had planned on a compsand with a 2# EPS core sandwhiched between 1/8" H80 D-Cell skins with balsa rails. This will be my first board (technically). I was told that a 2# EPS core would be overkill. Is this overkill in regards to price or density, or some other factor(s) that I’m not yet aware of? If it is in regards to price then that is not an issue as I am getting my EPS for free (thanks to my new best friend and local Insulfoam rep, and my boss who hooked me up with him).

Also, does anyone know what FiberglassSupply.com charges for shipping (only a couple of sheets of D-Cell)? I finally noticed their address, and wouldn’t you know it? I live only about 2 hours from their HQ in Washington State (man I love the Northwest). Need to find their shipping charges, might be worth a quick road trip to pick up my D-Cell.

Feedback is, as always, much appreciated.

Thanks,

J.D.

P.S. If anyone is near my area; Southern Washington, Northern Oregon. I’d be happy to pick anything up from Fiberglass Supply for ya when I make my trip (if it turns out to be cheaper than shipping). Might as well make the trip worth it huh? Also willing to share my EPS (in exchange for some much needed guidance) depending on how much my rep can get me at once. We get a truck from them once a month or so. This coming truck will be my first shipment so I don’t really know what I’m getting yet.

Nana ka maka;

ho`olohe ka pepeiao;

pa`a ka waha.

"Observe with the eyes;

listen with the ears;

shut the mouth."
Thus one learns.

2

the board will be really tough man

i did one in 2 pound for a kneeboarder mate who kills boards

i used the 2 pound because no vent and stiffness wasnt an issue

3

Tough as in too stiff? That’s what I’m afraid of. And balsa rails would compound that issue as well I’m sure. Damn. I think I’m getting 2" sheets of the stuff. Too stiff for compsand and too thin for a convensoinal “blank+stringer” type board. Unless I stack the sheets, but I heard shaping thru gluelines really sucks.

Well thanks, for the input. Now what to do…?

J.D.

4

WooHoo!!! I just graduated from “Newbie” to “User”. Well on my way to becoming a Swayaholic!!!

5

okay it will be allright

make it a bit thinner and no deck dome

a bit wider as welll to get the volume back

tough as in bloody tough

i did this board in 2 pound and double 6 all over

its not light but about the same as a strongy glassed poly

but its hell strong and no vent

wont suck water much

i think surftech were using 2 pound foam for years

go like 2 inches to 2 1/8 thick and leave the volume in under the chest

there no reason to thin out the nose at all

there no advantage to it because the core weighs sweet f all

modern thrusters are foiled away to nothing ot reduce the swing weight

this is NOT AN ISSUE with compsand

you can leave all that foam there and it will improve the board

why

please refer to greg loehrs thoery of pitch

imo if you put that foam back there you move the leverage point of your shoulder forward

this gives more go when padlling for a wave

your weight is more forward and leverage point more forward

this means you are catching more waves and paddling faster

and you still got the same size board

bloody wonderful

widen the nose out to twelve and you become the paddling terminator on the same size but lighterboard with no swingweight

the potato chip fools will just blink in awe

this is why id never base a a compsand foil on a PU board

the outline and rocker sure thing

but use the lightweight core to your advantage

6

Sweet, thanks Paul that does make sense. Now if I wanted to make a traditional compsand board, would 1.5# or 1.0# with skins be a better choice (remember, this is my first attempt with this method). I may still be able to change my order. I just don’t want my first board using this method to be a big pain in the ass, and then not be happy with my results. After I develope some skills I’ll be experimenting like a mad scientist, but for now I just don’t want any surprises.

Thanks again,

J.D.

7

right then use the 1 pound stuff

you are in a cold place

dont worry about a vent but be careful on hot days

skins minimum 1/8 thick

if you got balsa on the bottom skin , pvc foam stringers are fine

if i was doing all pvc skins i might think about a strip of wood in the rail/stringer laminate

or use a stiffer resin perhaps

8

If you want full sheets of Dcell, you’re probably better spending the gas to go pick it up from fiberglassupply. I just had a sheet shipped to texas, but I had them cut it into 12" strips lengthwise since I needed it full-length. Even then it was like $35. To ship a full sheet uncut would be more than $100.

9

If someone held a gun to my head and said use #2 with a hd foam skins, I wouldnt use underglass, only in a patch under my back foot. The rest would just be foam against foam. Putting glass under would be bulletproof but would surf like shit unless you really like ultra stiff boards. Some do, some dont, theyre not too bad in glassy surf. Really stiff boards suck IMO. Its like driving a car on its metal wheels w/o rubber tires.

10

You haven’t said what kind of shape… sounds like all the replies assume shortboard.

I’ve used more 2# than anything else. I don’t use vents. I’ve never had a delam in over 2 dozen boards over almost 4 years now.

Longboard shapes will flex no matter what the core if you make them wide & thin. Wide noses & wide tails grab a whole lot of water. If 2# is what you have for your shortboard, think it through from a longboard perspective - make it wider & thinner than your ‘normal’ board. Don’t use too much of that balsa on the rails. Use 2oz glass between the d-cell & the EPS.

Or like craftee says, skip that glass - I’ve had lots of success with foaming PU glue to join d-cell & EPS in vac bags. The caveat there is that the PU glue fills the void spaces in the EPS. This is great for waterproofing & further stiffening and doesn’t add any noticeable weight. However, because of the additional stiffening, you have to have planned ahead for it in your shape…

Give a little info on your planned shape & your own body size and we can probably help you modify your dimensions (the board ha ha the body is up to you) into something that will work with your materials.

All combinations work, you just have to hit the right blend of shapes & dimensions to make your materials & construction perform the way you want them to.

11

ok guys, not trying to hijack this thread but im just in the process of ordering a load of foam for start of term and want to include enough for me to start a compsand. couple of questions…

ive found a supplier of eps who can cut me anything from 10mm to 610mm blocks of 8’x4’. weights vary from 12oz to 26oz.

i happen to have found some very heavyweight cloth but not sure of its weight, how do i work this out? at a guess id say its about 20 oz!

also ive found a supply of plastazote foam is this anyuse for skins?

im thinking of having a 20mm slice of 12oz foam with a 10mm slice of 26oz either side then an 8mm plastazote skin and using the heavy cloth and bagging it to a former, reckon it’ll work? also thinking of maybe putting a balsa springer and balsa blocks for probox.

oh it’ll prob be about 6ft ish so i can get it in my bag!

12

The 2 puond could make a great larger funshape. Just what I would do with two sheets of the stuff. It will be so strong you could lone it to freinds and relatives who visit.

DARK SIDE FOR LIFE!

13

Thanks for the replies guys. In answer to dimensions (mine and the board), I’m average: 5’9", 175 lbs., I was planning on a funboard type shape, squash tail, around 7’2" or so. Mellow rocker and rails, maybe a little more point to the nose than a standard funboard, little bit of vee in the bottom. Tail and nose width still unsure. I keep getting “wide” as advice, that’s fine with me. Maybe a little bit of a domed deck.

Anyways, thanks for the imput. Would I be better off stacking these sheets and just hotwiring out the rocker and sticking a stringer in there as appossed to compsanding this stuff? I’ll have my foam guy send me 1# sheets next time, so I could just wait on my compsand until my second board. Whadday think?

Thanks,

J.D.

14

remember what a stringer does in a standard board; it keeps the layers of glass apart. the THICKNESS of the board is what gives it snap resistance. In the case of a lightly cored composite board, the potential snapping forces are transfered to the built up rail material, so they work very differently.

2# with no real skin build up other than glass will still heel dent. No big deal. Won’t affect the performance of the board. May affect longevity. You could always add just a layer of d-cell to the deck, either glass or GG under to provide you with a modicum of heel dent resistance. Also, airex of the same density is far superior to d-cell in this application (heel dent resistance). If you’re using GG or Elmers or whatever to adhere the two layers I highly recommend vacuum bagging it on a rocker bed and go real light on the glue. Apply it with a roller to the d-cell; don’t worry about “filling” all the little pores, and dampen the surface of the EPS with a damp cloth. Throw it all in the bag and come back after no less than 8 hours. You’ll be golden.

for a 7’2" funboard, you’re probably going to want to stiffen the board up a bit. You’re not talking about a high performance chip that needs a good amount of flex to feel alive. So, the easier route than GG might be to use some light glass in between the deck skin and the EPS.

on a board like that, if you wanna feel the flex, I’d think about doing a step-deck of sorts where the thickness of the board decreases dramatically after you’ve got your “thick” section through the middle for paddle volume (which everybody in the PNW needs). Thinning out the nose and tail will allow them to still feel sprightly.

FWIW, I built a couple of balsa decked boards with both 1.5# and 1# eps. They both go great and are heel dent free. Make sure you reinforce your finboxes if going this route. Full compsand? no. Alternative to just carving out your blank and glassing? Definitely. Performance advantage? Not a good enough surfer to be able to quantitatively make the argument, but they perform at least as well as the pu/pe’s I’ve ridden.

hth

15

Don’t over analyze it.

It happens here all the time.

we (yes me included) start going all over the map instead of just getting something done

when all it really is, is carving up some foam and putting a skin over it.

seems easy but the carving part is the hardest part…

much harder than your thankgiving turkey

although Mike Jones showed us you can use the same utensils on EPS.

obviously the easiest and most tested solution

is to just get a low tolerance blank from a known entity

carve it up and glass it heavy

pretty much a no brainer

figure out your design first

the rest are just options to choose from

keep it simple

cause in the end

once bit

you’ll make another…

go check out Point Blanks/Fletcher Chouinard’s site

I think a composite in either the Rocketsled(stubbvector) or the Mako would be a nice start for “fun board”.

Rocket Sled                                Mako

If you need to you can capture these and paste them into the APS3000 software of any design software to printout your templates. For your waves do these with a very slight vee running nose to tail.

Like Paul said with composite EPS construction keep them as thin as you can I’d go no more than 2.5" or 2.375" thick on a 7’2" for 175lbs maybe even 2.25"

For a starter with 2lb EPS you can just glass it using 2-3 layers of 6oz on the bottom and 3-4 layers of 6oz on the top and lap all layers. The multiple lapped layers of 6oz on the rail will serve as your perimeter stringer. The weather’s pretty bad most of the time and the waters pretty currenty(sp) in your area so you don’t want a superlight board in those conditions.

If you are putting on wood or HD rails don’t dome the deck too much it defeats the purpose and will stiffen it up too much. You can dome it alot if you don’t to provide support on a stringerless.

If you are planning on using sheets just polyurethane glue them togethor with Gorilla glue, Elmers PU or Sumo(my favorite).

Shaping through glue lines is a b*tch so plan your layers accordingly.

Use glass on fins

you can get something like this done in a couple of weekends and be surfing it.

If you’re gonna bag it you’ll need alot more stuff and time.

Unless you understand and figure out all the design things you’ll need to do to take advantage of that kind of tech, the board won’t ride that much better than a hand made board out of EPS. It might last longer and look better, but chances are it won’t justify the expense of all the other hardware/materials until you figure out the design requirements…

Again, once you make one

you’re more than likely to want to make another soon after…

16

Thanks again guys, I really appreciate it. And Oneula, yeah I think I’ll go that route with this first shipment of 2# EPS, I’ll just GG them and hotwire and shape like normal (well, normal as it can be with glue lines). I might bag it if I have everything set up by then. I’m working on a rocker table and I begged my uncle into giving me a refridgerator pump, he owns an appliance repair shop. So I do plan to do compsands exclusively in the future, I’ll get 1# next time around. Just don’t wanna waste this free 2#. And yeah glass on fins for now.

With the paralell glue lines in this set up will I still need a stringer? Probably should, I’d imagine. And I will lap each rail vs. HD foam rails on this first one.

Thanks much,

Jaydee

17
Quote:

FWIW, I built a couple of balsa decked boards with both 1.5# and 1# eps. They both go great and are heel dent free. Make sure you reinforce your finboxes if going this route. Full compsand? no.

hth

So have you done a board with a sandwich deck, HD rails and #1 EPS? So the bottom is just “naked” #1 EPS?

I’m thinking of doing my next longboard like that. But doesn’t your bottom get dented easily, I assume you’ll have to be very careful?

18

not even HD rails…just the deck; for heel dent resistance only. It was a great way to start learning the techniques of full sandwich composite with minimal expense/risk. Bottoms were 2x4oz with 6oz patch through the tail. Rails were lapped from under the wood, over the wood and the two bottom layers for a total of 16oz of glass; burly enough. About the same durability as a 4x4x4 pu/pe but no deck dents; only get dents in the bottom if you run in to something or store the board poorly. Works great for HP shorties; don’t think you’d get the stiffness or snap resistance required for a log…probably wanna go with higher density EPS, which was why I was suggesting it in this case where he’s already got 2# on the way. Neither perform as well as my UL corecell deck/bottom and cedar rail full composite, but pretty damn close with alot less work.

And, btw; BadHoudini; vacuum bagging is EASY. Requires planning, yes, but it’s EASY and crazy effective. Better than sandbags. Better than taping to the bottom of another board to try and copy rocker. Better than trying to apply 500 clamps. Really, really easy. Buy your pump at a scientific auction on line for pennies. Use one-shot polyethylene tubing they generally give away for free at lumber yards for wrapping up your lumber purchase; just check it carefully for holes. With good planning and a willingness to lam the outside of the board by hand, you’ll get a great deck patch lam with good final aesthetics. It’s a great technique; once you’re learned, you’ll see it extends to things far beyond surfboards; guitars, snowboards, chairs…you name it; if you can have multiple laminate layers, can craft a mold that will fit in your bag and can find a reasonable adhesive to hold everything together, you can make materials take on some pretty amazing shapes with this techinque.

hth,

g

19
Quote:

not even HD rails…just the deck; for heel dent resistance only. It was a great way to start learning the techniques of full sandwich composite with minimal expense/risk. FULLY TRUE. Bottoms were 2x4oz with 6oz patch through the tail. HANDLAMMED?? 6 OZ, ONLY IN TAIL THAT IS? Rails were lapped from under the wood, over the wood and the two bottom layers for a total of 16oz of glass; burly enough. About the same durability as a 4x4x4 pu/pe but no deck dents; only get dents in the bottom if you run in to something or store the board poorly. Works great for HP shorties; don’t think you’d get the stiffness or snap resistance required for a log…probably wanna go with higher density EPS, which was why I was suggesting it in this case where he’s already got 2# on the way. Neither perform as well as my UL corecell deck/bottom HOW THICK IS THAT CORECELL? WHAT DENSITY EPS? and cedar rail full composite, but pretty damn close with alot less work.

And, btw; BadHoudini; vacuum bagging is EASY. Requires planning, yes, but it’s EASY and crazy effective. Better than sandbags. Better than taping to the bottom of another board to try and copy rocker. Better than trying to apply 500 clamps. Really, really easy. Buy your pump at a scientific auction on line for pennies. Use one-shot polyethylene tubing they generally give away for free at lumber yards for wrapping up your lumber purchase; just check it carefully for holes. With good planning and a willingness to lam the outside of the board by hand, you’ll get a great deck patch lam with good final aesthetics. It’s a great technique; once you’re learned, you’ll see it extends to things far beyond surfboards; guitars, snowboards, chairs…you name it; if you can have multiple laminate layers, can craft a mold that will fit in your bag and can find a reasonable adhesive to hold everything together, you can make materials take on some pretty amazing shapes with this techinque. BAGGING IS THE BEST!! I RECOMMEND IT TOO…

hth,

g

Just spackle blank if low density and use 1glass to 1.1epoxy or so…

20

I was actually thinking of making the longboard with 3mm poplar sandwich deck and 3 cm poplar rails and #1 EPS.

I just don’t want to sandwich the bottom to keep weight down and to not overstiffen the board. Maybe I’ll do 1cm of XPS on the bottom to keep it a bit more dent resistant (I still have a lot of XPS left from making blanks).

I’d like to use poplar just because of the locally grown thought ;). And to make the deck bulletproof. I believe the strength has to be in the deck and rails so I want to make my board like that.

The bottom needs to be free to flex. When you’re using sandwich skin and HD (wood) rails, I don’t believe #1 or #2 EPS will make any difference in stiffness.