You very politely and kindly opened the door. You’ve actually left it open as far as I’m concerned.
Like at any good party, we all want to get in and drink all the free homebrew, but we should have enough respect not to ask for the secret recipe.
I think we will all go home with sore heads, but only some of us will try to work out the fine details ourselves.
If there’s a better concoction out there waiting to be found, maybe it’s one of us who finds it. We just have to open our minds and make a few independant trial and error attempts.
We don’t make mistakes, we just find out how not to do something in many different ways, always learning.
Thanks for your honesty, that really is the kind of answer I expected, but you can’t blame me for trying. I built some sandwich windsurfers 5 or so years ago, made a load of mistakes and learned a lot, you have helped point me in the right direction and that is more than anyone could expect, I only make boards for myself and mates but can see an exciting future in more ‘high tech’ custom construction methods, who knows where it may lead. I like all the other swaylocker’s will keep posting on my progress. I know I have to learn by my own mistakes, but it is just sooo tempting to ask you first!!!
Hey, I’m having a little trouble getting EPS except for 2lb density from a local shaper, we were talking and he said that it might be a little heavy to use the 2lb with the balsa laminate as its not really needed…jsut wanted to know what u guys thought. Ideally, should I use the 1 lb? if I used that should I be sealing and venting, is it somehow different with wood? I can’t really find the 1 lb anyway so I’ll prob just use the 2lb endro…Also heard the 1lb is cheaper, but I would have to get it in bulk…
Another idea, I thought I was at least semi original with this a few weeks ago, but the cat is out of the bag since I saw this on another thread, has anyone ever used a cork sandwiche? It has a natural honeycomb structure, it’s sort of a natural “suspension”, it’s light and it’s bouyant; seems liek it could be very applicable…
I know you mentioned this before but the discussions regarding heat and pressure to activate the resin bond in a sandwich construct and since most of us don’t have a decent vacuum setup yet how about this…
You lam the board as normal but use the plastic saran wrap roll tape to secure the epoxy+glass+ wood layer to the board and to seal it tightly.
You then take your board down to you favorite break about mid day dig a hole in the hot baking sand and bury your saran wrapped board about a foot deep and go for a surf.
Hang out at the beach all the day SURFING and enjoying the environment at the end of the day dig out your board and get ready to do the other side.
The temp of the sand in some places like here in the south/west side of oahu gets up to foot burning temps. Probably hot enough to help with the “bonding” process during pressure locking of the sandwhich…
Hell even a sandbox inthe backyard during the middle of summer could do…
Pros:
No cost
Heat+Pressure
No wap wap wap sound of the pump going off every 7 minutes
the untimate poor mans vacuum solution (Home Depot Blank + Sand box)
Cons:
Maybe not enough pressure to do the job
This all kind of occurred to me as I got heat stroke sanding down my balsa rails in the hot Ewa sun on a “bert” experiment CMP and I are going to try EPS+Balsa Rails+Epoxy Glass Sandwiched Wood Top and Bottom.
Maybe you Swayr’s can test this on Kauai in April (If it doesn’t rain)
Who knows maybe the Maile/Waianae homeless beaches can be converted into the next Surftech… You know instead of cashing in bottles and cans pay them baby sit and return lamming boards buried in all the hot sand along the west coast.
we once had a pump failure after a board had been in the bag for about 10 minutes …
my factory back then had a sand floored laminating bay , the sand was about 12" deep …
some customers rolled in just as all the excitement was happening , we had a window of about 20 minutes left to get pressure back on this board , we cleared a space in the glassing bay , there was about 4 of us frantically digging, clearing away enough area to lay the rocker bed flat on the concrete , then as were burying the board more customers were coming but i couldnt really stop in an emergency , so there was a gallery of intrigued people watching as we burried this board …
it worked fine that was like 10 or 11 years back and that board is still being ridden today …
after that we realised how effective sand was . so we started using plastic bags , plastic sheets and sand to do repairs , to keep the pump free for new boards while we still had a small pump …
i would say you need your hole already dug …
just roll up to the beach and drop it in , sand gives a fairly even pressure , just make sure your rocker is supported …
i can see it now all these mounds lining the beaches in oahu , with thermometers stuck in the sand and timers hanging on a stick , as soon as a timer goes off a bunch of kids runs for the mound quickly josling for posistion to dig it up and and put it in the collection return point and get there 5 dollar fee …
surftech will be overtaken by beachtech …
it has worked for me …
i cant see a problem with your suggestion , except look out for rising tides …
hey oneula…did the stretch wrap thing but used commercial bundling stretch wrap found at office supply stores…worked great. I put the bundled blank on a rocker bed with heavy bags on top. Still reacting at atmosphere tho…
We bought the same packaging wrap at Office Depot/Office Max.
It comes on a big roll on a stick. I see suppliers wrap their stuff in it all the time for shipping around town in the back of flat beds.You just start it around and hold the tension pulling tighter and tighter as you wrap it around itself.
We then held the plastic wrap lock down with fiberglass strapping tape over that.
Not as good as that heat shrink wrap but better than plain tape, especially plain tape over foam.
The mid-day beach sand burial sounds like a good no pump option because it has both heat and pressure. But not too hot like a steel autoclave oven would get. Kind of ecological too since your using would there anyway although it would be hilarious on some beaches like waikiki, to find an empty plot of sand you could use. Bert answered the pressure question.
I wonder how long you would actually have to leave it buried as the sand would cool in the evening. Most of us vacuum over night. Maybe a combination of the heat shrink wrap barberpoled around the plastic wrap would be an added pressure source although you wouldn’t want to crush the foam.
Then again maybe this is all a hallucination from getting over heated this weekend.
Dust management is the other problem I need to solve with no working area other than in front of the house.
Holding a shop vac hose in one hand while trying to shape/sand with the other absolutely sucks as a board building experience. Need $700-$800 for a Festools setup hmm maybe I could sell my parmenter vectors… Nah bad idea.
Bumping this thread because my project probably fits here better than in its own discussion.
1# EPS with d-cell. 1/8" for deck & bottom sandwich skin cores, 2 x 1/2" d-cell for building up rails.
Glued 8’ EPS pieces up to make 10’. Shaped rocker into the bottom first, before templating. Cut deck rocker/thickness and kept the offcut as a rocker table…
Once out of the bag, template the shape and square off the rails.
Then I laminate the bottom - outer glass. This was the tip from Bob Miller. No deck glass or d-cell yet.
Seal the deck with epoxy & microspheres. Probably not a coincedence they’re the same color as the d-cell. Added a little extra 4 oz because I knee paddle…
Then bag on the deck d-cell with glass underneath. That glass will tie in really strong with the lam from the bottom that lapped up & over the rails. I wanted a little extra nose flip so I did it with weight at this stage - once the deck skin is dry it’ll keep the new rocker in shape. The rocker from the original cut was flattened a little by curing glass on the bottom - twice - because of the d-cell step & the outside lamination…
Once the deck skin is out of the bag, clean up the edges. I used a belt sander but surform or whatever is fine too, just don’t hit the glass underneath. Tune up the tops of the blocks too - I’d left the deck side of the blocks more than 1/8" proud so once the deck skin went on, I could take them down to match…Use those straps with a belt sander, it’d be a shame to lose a board off the racks at this stage…
Laminate the deck’s outer layer. Another, larger knee paddle patch for me. Probably overkill, but I actually felt the board was coming out a little too light. I’m stuck on boards around 20# because I surf in wind a lot…
Next up, finbox, VENT, hotcoat…probably going to go with a plain sanded finish. I like the industrial look so far…
Looks great benny! I was just pondering my next project and thinking about doing the same thing myself. Looks like you have it pretty well dialed!
Couple of questions: Where did you source the D-cell and what did it wind up costing? Why did you lam the bottom before you d-celled the deck?
Again, looks really good!
Also: No stringer and why? How’s the flex? And did you seal the bottom before bagging on the dcell too, or was that just for the deck? Do you have a finished weight yet?
The board (and the technique) look great! Looking at how you did that explains a lot of things that I have noticed on Bert’s boards. I was wondering why he wrapped the top over the rails but not the bottom. I know you mentioned it before but what is the advantage of glassing it this way.
I glassed it that way just because Bob Miller told me he’s been doing that to add strength on stringerless boards. When I mentioned that in a post, Bert said that he wouldn’t have said that much, leading me to believe it was a slightly more advanced suggestion than what Bert had previously given away.
Schwuz, yeah, I sealed the bottom of the EPS too, before laminating on the bottom glass+d-cell.
Weight so far is around 18, without hotcoats. All glass is 6 oz. With 4 oz & no knee patches, I can tell by now that I’d have used about 26 oz less resin so far, or about 1.5 lb when dry. I also didn’t concave out the deck like I originally planned because I just don’t have enough of these under my belt to commit to drastic changes from my normal preferred shapes yet.
There’s some flex to it, but not much. About like the balsas, which do have stringers.
One nice thing about shaping the rails & doing the outside bottom glassing before putting on the deck skin is that you can see exactly how much deck skin you’re going to need & how far you have to bend it down. And then once its on, you know just how far you can sand off the edge of it before you start to risk exposing EPS. Because you will hit that layer of glass underneath first. Its a nice piece of comfort-zone work, as well as really stiffening up the perimeter of the board.
I’m pretty sure the flex will stay, its the flex-return that d-cell won’t have like wood does. But oh well, its fun to surf really stiff boards in super glassy waves sometimes and I’m glad to be testing the stuff that Bert first posted so long ago…
Thanks for the comments, guys…
Edit: sorry, forgot one of the questions…the d-cell comes from Swendsen’s Marine in Alameda. 1/8" is about $38 for a 4’x8’ sheet and 1/2" is $108. Its pricey. I already had the 1/2" because I’d bought a sheet months ago & used it as stringers in another project…Swendsen’s has a relationship with Fiberglass Hawaii in Santa Cruz where they can get any of FGH’s stock at the same price. And I have a commercial account so I get wholesale pricing anyway. If you buy the d-cell retail - by the square foot! - you don’t even want to know what it costs.
Its hard to see in the photos, but there’s a little bit of concave on the bottom and a little bit of dome to the middle of the deck. The nose of the deck comes down from the dome, but gradual, not like a step-deck.
Yes, there’s a layer of epoxy glass under each d-cell skin on top of the EPS to make sandwiches.
A question, in case Greg or Bert or any other more advanced composite guys is reading along…
I actually considered skipping the epoxy & glass under the d-cell and just sticking those skins on with foaming Polyurethane glue. Wouldn’t have to seal the EPS, would be out of the bag in 4 hours not 12, would be lighter & cheaper…any thoughts? Then maybe double-glass the outside of the deck?
Don’t see why it wouldn’t work… don’t know about the skin flex concept though…
I was thinking maybe there should a step by step balsa thread start to finish like Bert did here…
I think it help alot of the newbies out showing them all the steps we’ve had to learn ourselves…
Maybe all the homies woodheads can putt their ideas together in a thread and we can compile a simple how to make a balsa lam board from EPS foam using epoxy or UV resin in a variety of techniques…
Been thinking about doing a video showing step by step process but hosting it would be a nightmare. I guess you could convert it to flash somehow and find a site. But that would be a way to get the ball rolling for people to see how easy or difficult it can be to do this…