Comp Longboard

General Discussion
1

Here’s my second compsand board, my first attempt at making one I’d be willing to ride.

I’ve been shaping my own boards for 20 years now, and also worked in a surfboard factory way back when. I became inspired here right after Blank Monday. This hurt me hard because I had buckled my board the previous day and snapped my favorite beater into three pieces the previous week to that. What to do? Somehow I stumbled upon the original Burt sandwich thread and thought I could pull that off after seeing the successes of others. I obtained the vacuum pump from EBay and supplies from Joe W. Thus the experiment started. My old boards used the Clark 9’1"Y Super Blue blank with a 1/8" stringer, yes, a thin stringer. I’ve always had these boards glassed 4/4 deck and 4/spline bottom, sanded finish. Let’s just say I’m into performance more than cruising, and pretty much ride the same board in any size at the local reef. I’ve never had problems with snappage, and always attributed my luck to having a flimsy board that could absorb the wave and not be rigid and snap. Of course, mainly surfing leashless doesn’t hurt either, different story for a different day. Anyways, Burt’s theory’s on flex sounded very much like what I like in the boards I make. This also included the ugly parts about foam degradation and loss of performance over time.

Construction Details

I bought my blank at FUSR, it’s 2.5# EPS. My blank actually has a glue up stringer, no wood. I’m not sure how this affects the final ride, but at times it was very nice to have a straight line when working on the blank. I bought my balsa wood from LoneStar, the variation in weight was extreme. Some of the four inch wide planks were inconsistent in width also, any gaps proved no match for epoxy resin though, and weren’t a problem other than not being able to place certain pieces for better grain matching efect. I used the offline skins method, 1/16" balsa with 4oz flat weave on both sides. Pinholes are definitely an issue, my plan was to cap the entire board with another layer of cloth, resulting in three layers of cloth on the top and bottom. One nice trick I found was I can easily trim the bare skin after glassing with kitchen scissors. I drew my tentative outline on the bare skin and cut it out like a sewing pattern. After adding some rocker and thinning out the blank, I attached the bottom skin. The 2.5# foam is quite the mutha to work with, it’s tough stuff. When I added the skin, I strategically added extra glass patches where I knew the two futures and the FU box would go. Even though I supported the nose in the bag, I think I lost some rocker. I was nervous shoving the whole giant thing into the bag, but it slid right in. Set the pressure and wait over night. My homemade bag sucks and the pump cycled frequently, this is a problem because I can hear the pump from my bed, arghh. Better bags are definitely on my christmas list. Now I attached the rails. Per what I could glean from actually seeing a Firewire in the water, and mostly from Silly’s writings, I cut my 3mm x 50mm pieces into 12" lengths. Sucks, I can’t remember what I used for the first layer. I used CA glue for the rest, triple spot welds. This took a long time. Some pieces wouldn’t cooperate so much, they received the 90 second epoxy treatment and tape. The 3mm pieces made it almost all the way to the tips using just the superglue. My rail theory was short pieces loosely, coupled together with the inner and outer layers, and uncoupled from adjoining pieces. I have no basis nor claims as to performance. I’m 100% positive there are quicker methods to attach the rails. My buildout is 6 layers of 3mm for a 3/4" rail. Now I took the board down to my neighbor’s house and shaped it up. What a mess! At least it was enclosed in a shaping den. Back home, I glued on the nose and tail blocks, garden redwood bender board interleaved with balsa. Time to attach the deck skin. I traced the outline, just like described in the original post, works like a champ. The deck skin was created with only one layer of glass, when I attached it to the board, I glassed a precut sheet right onto the skin and placed it onto the blank and into the bag she goes. Now I fair out the deck, give the top and bottom a good sanding too, tweak up any rail issues and ready for the outermost layer of glass. I got some advice from Benny about finishing in the bag, but after one more failed test piece, I chickened out and finished the board using traditional hand layup. Oh yeah, the fin boxes, somewhat dramatic. I wound up measuring the futures boxes and hand routing the holes. Turned out fantastic, installing prior to glassing was a breeze. I also installed the center box prior to glassing the entire bottom. As it turns out, I’m a lousy machine sander. The board was hand sanded to 400, ready to ride.

Let’s cut to some numbers, I’ll try to give side by side comparisions where possible

Board Details

        New Board           Old Board

Foam 2.5# EPS Clark Super Blue

Weight 14 lbs 14.5 lbs

Length 9’2" 9’1"

Thick 2.63" 2.8"

N 17.25" 16.88"

M 23.13" 21.88"

T 14.44" 14.25"

Contour Flat to flat Slight roll to single concave to flat hard vee

This board is rock hard.

2

What good is this without some ride review?

Finally, we had some waves last Saturday. I cracked it. I couldn’t tell if the board was slow or what, but darn it, it took two tries to paddle out, it’s been years since that happened. It turns out I wasn’t the only one who had trouble getting past the shorepound, and sadly, I was out of shape from two weeks dry. The waves were well overhead, I was pumped, Only three other guys out, and they weren’t factors, the crowd would come soon. I caught some waves, and wasn’t really in sync. The board felt, umm, different. I could feel it resisting my efforts to turn, delaying me and messing with my timing. On the best waves though, where I had to drive and actually have skill to make the section, the board worked well. As the session progressed, I became more familiar but the board still just felt planky. A lot of the crew were interested in my creation. The next day, was rainy and stormy, perfect cuz I was stiff from the recent wave drought. Monday morning, the swell was still up, and I dawned it again. I used smaller sidefins, and the board worked better, still felt like it was resisting me though. When setting up for the roundhouse, I don’t know if it’s the width, the flat bottom, or the rail flexing, but the dang thing just wouldn’t get up on the rail. I did eventually figure out some interesting pivot type turns that suggested some slingshot effect, but I’m not sure yet. Yesterday, I got out at lunch, the waves were smaller, but so was the crowd. I moved my center fin back, and that seemed to help. I actually felt like I ripped a couple of turns. The board was still strange on the cutbacks though, either not wanting to turn, or turning way too suddenly. And sometimes I could tell my center fin was actually too far back, I’m going to move it back to the tried and true 6" mark. I’m crossing my fingers that the board is just going through it’s break in period. One thing, I’m now unafraid to bang rails with a surftech.

Here’s some pics from last Saturday, thanks to John Slavin at www.johnslavin.com

I nice shot, I should probably buy this one.

The board didn’t exactly hit the lip where I wanted it too, drawing out the turn.

Sometimes, you have to ride a foamer…


3

Two more shots

Note the front heel, @%##$ board wouldn’t turn, had to muscle it.

I forgot to plug in my GPS unit

Next board starts in January


4

very nice board Scott

i can tell that youve built a stiffy there though

can you give me an indication of its flex characteristics

i should suggest that a low density core would make a big difference mate

5

Great work Scott!

I enjoyed your thread.

I know the feeling of differance and weirdness on compsands myself.

you might want to try the board with 3 thruster sized fins around 5" each. The H2 Large set works incredably well on performance longboards too.

Cheers!

6
Quote:
The board felt, umm, different. I could feel it resisting my efforts to turn, delaying me and messing with my timing. On the best waves though, where I had to drive and actually have skill to make the section, the board worked well. As the session progressed, I became more familiar but the board still just felt planky.

More tail rocker may have been the call. At this point you should try moving the center fin way forward - that will loosen it up. You may also want to try a smaller fin, or one with less rake.

7

I’d ride it :slight_smile: Nice work, Scott.

I think its the double 4 oz outsides that make it stiff. Silly & I have been back & forth several times on whether its core or skin that has the biggest effect on flex/response. I think (and thans for providing the numbers from your old board - that’s really useful) that since you went wider & thinner than your poly, it should have been flexible. Next time, if you want to pre-make those skins, just put on the inside glass & paint thinned resin alone on the outsides. Then do your hand lams on the outside again…

If it was me, I’d probably try riding it as a single. 9" Farberow flex has good base for drive, a swept tip for noseriding, and some twang for loading up on bottom turns. 6" off the tail to the back edge of the fin should still be good…

8
Quote:

I think its the double 4 oz outsides that make it stiff. Silly & I have been back & forth several times on whether its core or skin that has the biggest effect on flex/response.

Its Both :slight_smile: I bet that board would go off in the 25-35 foot range. Any less power than that and I doubt that you would ever get it to flex. If it was me I’d change both your foam and glassing schedule. However, its a really nice looking board!

9

I agree with most all of the above. Definitely the foam is an issue, I still have another blank, I’m going narrower and thinner. I don’t have the hotwire gig going at all, I’m exploring a handheld for use with routing out springer channels though. A less dense blank would help, I’ve got to do some shopping for that. The glassing schedule I think is overkill too. I just haven’t figured out the best method yet for eliminating the pinholes, the second layer of glass is effective but excessive. Benny’s method will get some experiment time during the holidays. As to fin placement, my thought has always been that back is better than forwards. I feel one loses leverage to get on the rail as the center fin is moved up. Light riders think it makes the board looser, but it’s more that they’re pivot turning in the first place. I do have another set of sides to try out and tons of adjustment in the center box. More work to do in this area. I also did put a lot of glass underneath the bottom skin in the tail/box area, combine that with the 10.5 box and no wonder it’s stiff. The surf came up today, lowtide at lunch looks promising, more ride reviews forthcoming…

10

The fins just keep you from spinning out. If you put them back on the board, they’ll move the pivot point back, and make the board track straighter (more stable). Moving the fins forward also moves the pivot point forward and makes it easier to initiate turns (looser). Doesn’t matter if you’re heavy or light. Also, less rake will make it looser. More rake will make it more stable. It will be faster to get on rail with a looser setup… staying on rail (not spinning out) is another story. Jamie O’Brian frequently surfs with no fins, just for kicks… no fins, all rail. I personally like stiff, small fins. Usually with the center fin moved way forward. Makes the board less stable but much easier to change direction. If my board is set up too stiff, I spend too much time thinking about it. Looser boards “disappear” under my feet, and I can just be where I want on the wave.

I’m 48, 5’8", 185lbs, surfed for over 42 years, ex team guy, surfed thousands of boards, industry professional.

11
Quote:
Quote:

The board felt, umm, different. I could feel it resisting my efforts to turn, delaying me and messing with my timing. On the best waves though, where I had to drive and actually have skill to make the section, the board worked well. As the session progressed, I became more familiar but the board still just felt planky.

More tail rocker may have been the call. At this point you should try moving the center fin way forward - that will loosen it up. You may also want to try a smaller fin, or one with less rake.

Ditto on less rake.

regards,

Håvard

12
Quote:

A less dense blank would help, I’ve got to do some shopping for that.

Scott,

From the stringer set up and glassing schedule you describe, your PU/PE board probably had a bit more torsional flex than a standard longboard. 2.5# with a balsa skin would be way stiffer than you’re used to. Core (skin or blank) density and thickness are the major flex factors.

I think you’d be better off with 1#. Find an EPS place that has a cnc hotwire, find a Clark blank you like in the old Clark catalogue pdf and see if the shop can cut it for you. People here can probably help you out with a .dxf file if the cnc guys can’t copy the profile from the pdf. Not sure how you did your skins but the golden rule with balsa is always glass in dropping temperature.

13

Bingo on the torsional flex. One thing I did note, my tail is mighty thick. Based on the depth of the box route, I could’ve shaved at least 1/4" if not a 1/2", this is a big factor also. Like Burt always said, there’s a ton of variables.

More Ride Review:

I went out at noon today, caught a bunch of fun ones. Today I moved the center fun up to 6 1/8" from 5 7/8". Today I felt like I was surfing, got some big lippers and figure eight cutties, things are looking up in the performance department! I was coming much much closer to my target point on my bottom turns. On top turns, I’ve adapted by throwing my hips more hula style into the turn, this helped bring the tail around on slash turns. I’m wondering about the so called “break in” period. I’m gonna let the kids play trampoline tonight in an effort to get some flex cycles into the board. One interesting thing, now that I’ve got a woody, I’m meeting fellow Swaylockers out in the lineup. This is new for me, because I’m usually the grumpy local, reserving my aloha for the crew, but now I’m spreading it around further. Who would’ve thought you could get something like this just from making a garage board? Thanks Swaylock’s.

The skins were made in the evening, typical temps ranged from 70 to 60 degrees F. The bottom skin received top and bottom glass, while the top sheet only got top glass in the initial skin creation. When there’s glass on the outside of the wood, it readily conforms to the compound curves on the deck. I’m thinking the pinholes are more of a pretreatment issue. I’ve gotten them on every single test sample piece. I’m still undecided whether to pursue sealing or to allow the resin to penetrate the 1/16" panels. The weight isn’t much of a difference, but I’m sure the strength and water resistance will be better with saturated wood. Benny is pretty confident with the brush resin on before cloth technique. It’s less steps. Sealing the wood first is more work and for dubious gain. I guess I know what to do now.

Ok North County guys, where you getting the 1# foam at? And I’m not talking driving up to Ontario for a giant block.

14

You could buy directly from Ken at American Blanks (he makes it down that way and is a great guy) or Bashim’s sells his blanks also.

15

Sweet board Scott!!

I know what you’re saying about people approaching you. It can get old sometimes trying to explain the process to people over and over again…“No, it’s not a veneer, its a sandwich…” Heheh!

But yes, definitely a stoke.

Hey Benny,

Quote:

Silly & I have been back & forth several times on whether its core or skin that has the biggest effect on flex/response.

what about the thickness of the rails? have you or Silly played with this variable for flex? what have you guys found?

Cheers,

Rio

16

yes

but composite panel theory appears to be the most distinguishing factor

i agree with benny though about xtra glass

scott if you make the blank

seal it and glass as normal

or preseal the skins before glassing while stop pinholes

inside glass as per berts original post