Appletree
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Airinside
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KT Foiling
Naish and Duotone
I tried few hollow boards , they are amazing
But
I dont think the value for money is good enough
Good EPS carbon sandwich board have great performance as well and much cheaper then the hollow ones, also not every hollow construction is good , i seen few brands that might make very light board but not stiff enough as you want hollow to be
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im wondering about how easily they ding, and how catestrophic it would to have a small ding you didnt notice that turned into a crack, etc… would it fill up with water and sink to the bottom of the ocean?
At least the appletree board likely floats since the skin is made of two layers of carbon sandwiched around a foam core. Not sure how much happier you’ll be with a board with maybe a few litres of buoyancy 10k from the shore than a board that just sinks though? Also probably close to impossible to hoist the board out of the water and into a boat once it’s filled with water.
On the other hand that appletree board looks pretty bulletproof. I don’t think I would be that concerned about the board getting filled with water.
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I had a hollow surfboard years ago (made by …lost). I was surfing in Costa Rica when I got a small ding in it. Water started filling the board, and it slowly began to sink. I was surfing a reef about 100 meters offshore, and by the time I got back to the beach, it was barely staying afloat. It was one of my favorite boards ever up to that point.
I’m sold on hollow (so far).
First paddle up on a hollow KT 106L - really liking it! https://youtu.be/tnNlkntoUAQ?si=rUKdSHve4a2jE7df
I also have a hollow Appletree on order.
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This type of construction (epoxy and glass, not carbon) has been used for boats for decades.
Generally enough floatation is added so the boat won’t sink if the hull is breached.
I personally don’t care if the board is hollow, but, the bulkhead style construction could add stiffness that cannot be achieved with a foam blank.
The repairability with less likely hood for additional damage from dings is a bonus. No real concern with delaminating because its not a laminated blank.
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I didn’t feel like starting a thread, but maybe I will someday with the entire project. There are several folks posting up their homebuilt hollow board projects on youtube and instagram. For some reason I can’t get on the facebook group but I bet there are some projects going there too. Especially since the KT video came out which showed how to do it.
I shaped a board and made a mold more than 2.5 years ago for my personal hollow board project. This is before Starboard even showed their hollow board and certainly before KT. I lost a little steam because shortly after I decided I didn’t like the board shape - too thick to my eye. Recently I’ve been working to finish off the project just to work out the lamination schedule and get it on the water so I can check how it feels, adjust the layup and make a new one.
I don’t have time to pull all the photos into one place since the project has been spread over two years, but I just pulled the “hull” out of the mold this week, so the project is getting closer.
The layup is
1 layer of medium modulus carbon on the inside with some reinforcements where it is 2 layer like underfoot for example
1/8" nomex honeycomb everywhere, but 3/8" honeycomb underfoot
1 layer of medium modulus carbon outside the honeycomb and 1 layer of carbon/innegra as the outside
This thing is super duper stiff even before bonding the deck to the hull. Just need to put in the tuttle foilbox which will tie the deck to the hull underfoot, bond on the deck, and hotcoat/sand. Planning on keeping it clear because the innegra/carbon looks so cool.
Its 8’x18"x130L. And I wanted it to be under 10 pounds but I’m not going to make it. I laid it up way too wet and it looks like I might get 11-12lbs which would still be sick for a 130L board. I’m pretty convinced it will also be nearly bulletproof with the innegra and super stiff with the honeycomb. Feels like it so far.
Don’t ask me to make you one.
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A beauty.
What are the weights of the cloths?.
And where do you get that carbon innegra?, it looks alien cool.
I used 150gsm textreme. All from composite envisions. This stuff is a real pain to work with and probably not worth it. All the weight benefit goes away unless you can get the epoxy/fiber ratio perfect. I wasn’t able to get an ideal ratio but in theory it’s possible. The cloth doesn’t drape for shit either. I wouldn’t do it again except maybe on the deck and only wherever I can use peel ply to draw out excess resin.
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Yeah,i have used spread tow on a couple builds and i positively hate the stuff.It also has terrible ding resistance, the carbon innegra is probably better at that though.
For Carbon innegra i have used castrocomposites woven 152gsm.
Not a hollow board but with the aid of 3M Super77 (EU version) you can dry lay it on foam and get perfect tips and tails.But maybe for a hollow it would leave glue
residue on the outer skin.
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That’s super cool jon. Would love to see some more pics of the build at some point.
Would also love some more info about how you handled the join of the two halves. Have you done a top flange so that you can lay up a 90 degree lip two the side wall?
Board looks sick.
Cheers
I wouldn’t do this again because laying up the “hull” was awfully difficult to layup. But this is how the mold looks, I laid up the hull in the bottom mold with the hull fence bolted on. That way I can glue the deck down directly onto the hull. I hope that makes sense. I’ll take some more pictures when I finish the next few steps.
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Did you vac bag or hand layup?
both.
table-wet the cloth with a poor-man’s prepreg style method. Thin painters drop plastic on the table, wet out the cloth and put another layer of thin plastic over it. Keep squeegee the epoxy until it is as thin as it can be. Then you can cut the cloth with the plastic face layers to keep the edges from fraying. This method is almost a must with the spread-tow because otherwise it is super difficult to get the epoxy wet enough but not too much.
Then place the layers into the mold (with core) like you would with pre-preg.
peel ply, breather, vac-bag with full vacuum.
I’ve given this some thought(dangerous I know)
I feel like this method makes sense with a few compromises that make a less sexy board but possibly better and more practical and vastly easier to build.
Hard chined all around - I think a hard chined shape is fine and this lets you make a mold right out of melamine coated ply with silicon in the gaps. It also lets you easily cut your core to fit the developed flat surfaces when it comes to that. - I made a totally flat and slab sided (cross section is a rectangle at all points) downwind board from marine plywood and it’s great. Shape Doesnt matter half as much as we think. The aesthetics of surfing are the worst thing to ever happen to foil board design and continue to be a plague.
Stop trying to replicate a smooth surfboard rail - deck fits shoebox style over the hull, maybe even a bit of a rail on the overlap to help knock down spray. Go really wild and make It like a sunfish sailboat with a curved down hull deck joint so The spray goes downward.
Flat deck - deck is a male mold with a grippy peel ply finish on top. Just cut a piece of melamine coated ply to the hull outline, packing tape the edges and pull a flat part to shoebox over the bottom.
I’m in the middle of building a cruising catamaran at the moment so no new projects (also TBH prone for life so I don’t care enough about big boards to invest time) but someone run with this.