I've seen a lot of enthousiasts on this forum about building boards and due to the help of some awesome people, I succeeded in building my first board. Now it's time to try and give back to this small community along with it's potential members that aspire to pick up the sandingblock and squeegee.

A bit of background info: I live in a 3rd floor appartement. To have the space to tackle a project like this, I decided to purchase a plastic Greenhouse that's big enough to store the board and tools and should alow me to do some small jobs. If the weather alows for it, I can take the board out and proceed the project.
The reasons I started this hobby are numerous: it's cool, gives me a deeper understanding of our sport and is potnetially a lot cheaper than getting a factory board. Especially for foiling where there isn't so many quality used (freestylewave foil) gear for sale yet. I reckon shaping a slapper is also more tricky, so this seemed like a good startingpoint.

Previous project: 200x79 lightwind foilboard with cork deck and glass only bottom. Made a lot of mistakes, learned a lot. Haven't posted anything about it because I first want to do some more testing.

The goal of this thread: giving some insight into the steps and effort of building a simple foilboard, along with it's pleasures and pains.

This project: a 180x65.5cm 130l pocket foil. I love foiling with my JP 101 2017 freestyleboard because it is fairly quick to go up, super playful and very forgiving. This board will feature a lot of elements from what I've learned by riding that board, such as: centred footstraps, round rails in the front, mastfoot close to the frontfoot,... I like the freestyler, but because I'm ankle to knee deep when slogging, I need a board that has some more float to improve low end.
The shape:
- a 'parabolic' rocker to keep as much volume in the nose as possible (these short boards are very unstable even given there higher volume) and have a lot of gliding surface.
- flat bottom, like the JP but without V. Wingfoilers used to have huge bevels and concaves. This will likely fade away as more wingers use high aspect foils that need glide (so also a board with sharper rails and flatter bottom). Tbh, not sure if completely flat will be ideal because it might feel sticky, but my foil has some tailkick build into it so why not try it out.
- a whopping 13.5cm thickness to pack a lot of volume in a compact shape.
- slightly rounded nose and tail for jumps an to be able to push the foil down when taking off.
- rails are round in the first 1/3rd to sharp in the last 1/3rd.
Construction:
EPS100 (industry standard is 60, but 100 is so much stronger. We'll see if the weight penalty is worth it), 0.6mm fineer with a 160gr layer of fibreglass on bottom and deck (not on the rails), covered by another layer of 160 with some UD carbon to provide extra strenght where it's needed. Very basic layup that's of much better quality than the cheaper construction of the industry brands (rrd e-tech, tabou mte, starboard starlite,...), probably stronger than a lot of the 'wood' sandwich boards too. Don't know how it'll handle excessive jumping usage, but I'll keep you posted on that. Should be a lot easier to build than a PVC or even cork board. The plan is to push this board as hard as possible and then revisit the shape and construction, if needed.
Budget: 300 euro

Last weekend I did the basic hotwiring (deck + bottom and outline). For this you need a hotwire, some markers and decent templates. Nothing to complicated if your hotwire can get hot enough and you keep a fluent movement.

If you're going for a bottom shape, this might be the Point to start on that, but since I make this one completely flat to see if that's something that could work, I skipped this part.

Next is the rail with the hotwire. Mark the rails and then stick some maskingtape along that line. The hotwire melts through the foam, but not through paper maskingtape (ducktape melts so finally something that ducktape isn't suited for!). I did the railshape by guessing and looking at the foam blank, but you can use tools or do some calculations. Check some surf shapers video's to find a technique you like. First I did one deck cut, than a bottom and finally another deck cut.
So far I'm pretty happy. The rails are much better than expected and there's only one spot that'll need filling (messed up a bit by over hotwiring on the deck). Only downside is that at this stage I hope to be around 125 liters but made the tail last minute slightly wider and am now at 135. Would be a real bummer for a slapper, but for a foiler I'll keep it like this.

Next step: sanding away hotwire marks and blending those rails. It looks like there might be some wind the upcoming evenings, so I'll start somewhere during the week I guess.
During the weekend the plan is to install the foilbox, along with preping and vacing the wood on to the blank. Then it's only installing plugs, doing a wet layup with a layer of 160gr glass on both sides, sanding, applying a hotcoat and sanding again that's left!

A final note: there are people that are way better and more experienced in this, but should be interesting to follow along for those that feel inpired.

Here are some pics that for one reason or another decided to tilt 90? to the left.

Very Cool NicoDC! Keep us posted!

The wind wasn't that great so had 30min left to start blending the deckside of the railcuts.
I use a 80p sandingblock to flush the railcuts close to a smooth result. Long strokes to keep an even result and shorter ones in a different direction to where it's needed. By using your hands and sliding over the rails you'll know which part is good and which one needs some extra sanding. Light (sideways) helps a lot to spot some spots that stick out too!
When close to finishing, I grab a sheet (20-30cm long) of 100p and move it up and down while sliding along the rail to get a consistent and smooth result.
Don't forget to wear a mask at this stage, breathing in foam dust isn't fun. In all my enthousiasme I forgot to put on glasses and felt the dust irritating my eyes at some point.

Tomorrow it's time to flip the board and finish the blank. If there's any deep cuts left, I'll probably fill it up with spackle. On my last board I used a lot of it and covered most of the blank. EPS60 is more porous so there's a chance you fill those holes with epoxy (making it heavier) or not using enough and having a dry laminate. I think this foam won't need any.

Time for an update:

Finished the rails and absolutely love those curves.
The board is 133l now so with the glass & wood skin it'll be like 135.

Started preparing the wood veneer layer. Puzzeled the pieces of .6mm maple together, cut a layer of 160gr fibreglass and laminated the together with +-225gr of epoxy.
In retrospect, would've been better to go for a single sheet of would or full lenght strips because now I have some gaps that'll need attention and will weaken the construction I guess. It's a learning process.
This is the construction I'm attempting:
(part 1 out of 3)

Happy with the result and progress so far!

Did he just put a dent in his in breakable board right where he hit it.

it's a chunky boi

Great stuff,

I may have missed it but what will you do with the rails ? Will you wrap the bottom glass around them ?

Very chunky boy indeed.
The thickness (13.5cm) will for sure help to strenghten this construction. On the rails it'll be 2x 160 glass from the layers that go over the wood. It's a very simple layup

It's not chunky, everything else is too skinny! I like big butts and I can not lie! It's all the about the base about the base no treble! All the right junk in all the right places!
Seariously bro, good on ya for having riding skills but still choosing volume. Very new school!
I have one I am modeling that is 1.5m long and 15 cm thick!

I don't really see the point of saving volume for windfoil boards. What's there to win? Maybe 200 or 300gr? You could argue it impacts swingwheight but as these boards are so tiny, there is almost none. It's more of an ego thing I guess.
The most new school feature of this board for sure is the parabolic rocker. Years ago having a board with a pointy nose facing the sky was the way to go. Then it vanished and now it's back in this board, altough not pointy because of the wide nose. Should optimise the planing surface!
Next up would be a 160cm, 105l wing/wind or a freestyle board, both with the same rocker concept
Curious to see what's on your mind.

The result of the veneer laminate is worrying me. It doesn't stick to the wood like I hoped because it started to curve so it has a high risk to delam. It'll need some fixing and the next sheet will be done differently.
To fix it, I'll just proceed as planned (cut to size and laminate onto the blank) and inject some epoxy where needed before applying vac pressure. Info on my super cheap and easy vac life hack will follow soon!
I'll make some mistakes so you don't have to.

Here's a pic of my rocker template and one of the wood laminate:

Loving the build but I recon that laminating might cause some problems down the track. I've made a few wooden surfboards and use the method in this video (from about 4mins) to join the panels on the deck and bottom, a swelling PU glue to fill in any gaps also helps.



Another trick I picked up was once I'd joined all the bits together, coat the timber with a super thin 25% diluted epoxy coat to seal it prior to laying up the glass. This is a bit contentious in some of the forums but I found the diluted epoxy would soak into and seal the timber. As different bits of timber can have slightly different absorption rates I'd end up with some bits swelling/warping more than others leaving an uneven surface, I don't think this step adds any strength but it's much easier to sand the bumps out prior to glassing and I end up with a much better finish for a minimal weight impact.

Keep posting super keen to see how this works out.

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Thanks a lot of sharing your knowledge!
That's some beautiful wood work there.

I'm affraid that I can't copy that technique because the veneer I have is 0.6mm thick, so it would simply bend and crack.
What it tells me tho is that for sure a single (or tightly clamped) sheet is the way to go.
Do you use a vacuum?

I'll do a restart. Fixing the current laminated sheets would be very time and probly money consuming.
Couple of options to try again:
1. Cut the outline of the wood and laminate straight on the eps core, only glass on top. This sounds easy but less strong
2. Cut the outline, laminate a layer of glass on the core and trim it to the precise outline, wood on top. More complex but stronger
3. Get a single sheet of wood and try the same technique again

I haven't done any vaneer work on EPS blanks, only builds like in the video, and also the thinnest I've gone in relation to jointing the timbers is 4mm so anything I think of from here is guesswork .

I'd be leaning towards your first option, laminate the timber to the EPS and then glass over the top. I recon this is the go because a) it's .easiest and b) not too sure how much strength a .6mm vaneer would add (happy to be call out on this one though). If it's the extra layer of glass you're looking for you can always add that as a part of the layup (plenty of surfboards have an additional layer of glass where your feet go).

Don't know if that helps?

Good luck and keep posting updates, you've got me thinking about knocking one up myself.

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Panno said..
I haven't done any vaneer work on EPS blanks, only builds like in the video, and also the thinnest I've gone in relation to jointing the timbers is 4mm so anything I think of from here is guesswork .

I'd be leaning towards your first option, laminate the timber to the EPS and then glass over the top. I recon this is the go because a) it's .easiest and b) not too sure how much strength a .6mm vaneer would add (happy to be call out on this one though). If it's the extra layer of glass you're looking for you can always add that as a part of the layup (plenty of surfboards have an additional layer of glass where your feet go).

Don't know if that helps?

Good luck and keep posting updates, you've got me thinking about knocking one up myself.

Indeed the .6mm layer doesn't work like a traditional sandwich layer. Decent boards (so the more expensive production boards) have 3 to 5mm pvc to add strenght. By strenght I mean: 1. Stiffen the board up and 2. make it more impact resitant. This in comparison to a simple EPS only board.
Again you can build boards with glass only, that's what a lot of the manufacturers do for their cheaper freeride boards.
I'll attach screenshots of a RRD magazine from a couple of years ago so you can see what they use. Be aware that even this is a marketing document, in reality the construction will often have less material than they promote (no pvc on the rails, only tiny wooden patches and carbon,...). Not to put RRD on the spot, a good friend of mine does board repairs and he sees these construction coming back in all brands. RRD just shows the most detail.

So, can a board be build with eps, epoxy and glass only? Sure, it comes at a slight weight penalty but according the industry it should even be tougher than full pvc sandwiched boards (can't say that's factual nor deny it).
I could build a fun and lasting board like that, but I wanted more of a challenge so that's why I attempt to include a veneer layer.
Besides the fact that potentionaly it looks dope, I thinkg it adds strenght:
1. Stiffening up the board (prevent creases and snapping). Most of the wood fibres are unidirectional so when jumping and landing flat, they all stretch and compress together in an efficient way at a lower weight penalty than adding more glass and epoxy.
2. Increasing impact strenght. The wood should dispense the load of heel impacts better.
Putting the wood between glass layers improves the whole construction because that way impact and load can be distributed better throughout the construction.

That being said, I'll probably go for the first option because I'm lazy and just want to go surfing!

NIcoDC,
Are you vacuum bagging? Thats the only way I can see that veneer getting pulled down. For what its worth I think the veneer makes a great structure.

Here is inexpensive pump that has served me well. I won't even do repairs without one.

www.harborfreight.com/25-cfm-vacuum-pump-61245.html?_br_psugg_q=vacuum+pump

You can use drop cloth plastic or even trash bags for the bag. In fact the trash bags confrom and stretch to board shapes nice.
The mastic tape can get pricey but often you don't need it. For instance to bag the whole board take big sheet of plastic and fold around the board. Roll the edges around them selves on the three side and clamp each with a spring clamp. When the preasure drops the rolled edges seal themselves. Pracice/play with it before the glue comes out.

I do not have a cheap solution for breather or peel ply but its worth the cost. Even as a student your time is priceless use it to create quaility gear. Shoot just the cost/shipping and hassel of the foam makes the extra cost and time appropriate.

Keep the vacuum preasure below 15psi or you will crush the foam. It happens about an hour in after all the air has been pulled from the foam, this is roughly the time most lower their gaurd and walk away.

You may not have this store but you can find a similar pump. All in under $100 it's a no brainer and will have a tool you will use for years to come.

I don't have a vacuum system but yes I vac!

Here's my top tip: using a vacuumbag for matrasses (or clothes). I've got one that's 130x240cm and costs 15 euro. For that price you have sealing tape and maybe vac plastic. It has a zipper and valve so with a hand pump or vaccuum cleaner you get all the air out

On my previous board it worked well. I was worried about the blank tha could crumble or a dry laminate, but that was all for nothing.
The bag died during the last stage (the outer glass of the top of the board). That was either because of cured glass that had punctered throug it, or more likely because of a repair I did in the meanwhile that overstretched it.
What I've learned is to adapt my technique a bit. The plastic is thic so I need to suck the air out in steps so that I can make sure it's nicely flat and tight around the corners.

I get you that peelply, bleeder and dispenser layers are fairly expensive. I've seen cheap 3-in-1 solutions but that only for flat surfaces.
For this board I only want to vac on the wood. Vaccuuming glass is not needed. It saves some weight and in theory is stronger (epoxy to fibre ratio is better). But surfers skipped it for ages and so far it worked.
Carbon floats in a resin matrix so in that case you need a decent vac system.

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utcminusfour said..
Keep the vacuum preasure below 15psi or you will crush the foam. It happens about an hour in after all the air has been pulled from the foam, this is roughly the time most lower their gaurd and walk away.

Does the pump you linked have a gauge or do we purchase that separately?

Good tips.

Paducah,
I think I bought the gauge seperatly after I realized how easy it is to crush the foam!

Time to bring this one back to life.
Started working so didn't have as much time as I wanted to proceed, but this is a process to enjoy so no need to rush.

the veneer failed big time!
i tried laminating glass onto a sheet, but it just started folding and was unusable.
i tried vaccing a layer of glass and the wood straight onto the blank, again it started to give a "delaminated" result so I quickly peeled off the wood before it became inseparable. I left the glass to cure and'll tell you why in a next post (it's useful to not make mistakes at a later stage).
now I think there are two things that have caused this:
1. The veneer wasn't suited. I went cheap and bought scrap maple. Should have gone for a renown wood (like balsa or bamboo) and preferably just one big sheet of it or at least full length ones.
2. The vac setup failed. On the previous board, I used a big industrial vac cleaner (the one you use for cleaning a car) and now a regular household one. It was less capable of sucking the air out before I had to turn it off. As a result, I didn't have enough pressure.

Anyway, this highlights another key aspect of board building: problem solving.
Running into unexpected trouble is common, so it's normal to go back to the drawing board and rethink and adapt.

so what's the new plan?
all glass, like the cheap production boards, and some carbon patches (I got 1m twill and a lot of UD tape for a project that I still haven't tackled). I guess there's no need for carbon, but since I have it I might use it as well.
400gr of glass on the bottom, 500-600 on the deck, overlapping rails and up to 1000 in the key areas like feet, mastrail, footplugs and foilbox.

I hope to insert the plugs tonight and start the bottom glass this weekend! Keep you posted.

Its not the type of wood in the veneer - maybe too thick? I use 0.6mm pine and it conforms just fine with vacuum at about -40kpa
Maple should do the same

TBH you will get almost the same propertiest (apart from ding resistance) with a layer of unidirectional carbon. Whatever you use needs to contact the foam 100% so you don't have the delams. For wood this means really good bagging technique that takes some practice on a compound curve.

For a first time user, I'd say use cloth not wood, wet out on a table then transfer to the foam so as to save weight. Squeegee well, then you know its conformed to the foam. I think everyone has frustration with wood the first couple of times but if you're using like 1mm or something it is never gonna happen

thanks for sharing!

It was .6mm but had a lot of these "eyes" and indeed not the vac or skills that are needed to pull this off.

Carbon and glass patches will have to take the load and prevent dings. I don't care to much for the weight. Balz mullers foilboard (108l) weighs 9kg! Shows that weight is not as relevant as it is for a slappers and that building a strong board requires extra materials and thus weighs more.
I still have a big sheet of 1cm tick 80kg/m3 pu foam. thought of putting it under the footstrap area, but the likelihood of running into problems seems pretty big so it's probably a no go. What do you think?

tomorrow will be devoted to the plugs and a polyfilla!

I have build a wing board that had a foam sandwich (thicker divinicell) only on the top, starting about 1/4th from the front and going most of the way to the tail. One layer of glass between the foam and the d-cell, glued together with epoxy and lots of weights and some clamping (no vacuum). Worked for the top since it is pretty much just flat. The board has held up for more than 110 sessions. I've had several windsurf boards that needed significant repairs after about 100 sessions, so that's pretty decent.

So I think using the 1 cm pu foam to make a sandwich for the top would be a good idea. But I'd be wary about just using it for the footstrap area, unless your feet are never ever outside. One of my boards needed multiple repairs in the back foot area, right where the wood reinforcement ends. I often put my back foot in front of the straps in lighter wind, or further to the outside, partially next to the foot pad, when planing. Both of these spots required non-trivial repairs after a few dozen sessions; a first try to just fill with PU foam and glass over, which works fine for broken noses, did not last more than a few sessions. Had to get a proper vacuum pump to reconstruct the sandwich, and added some extra EPA.

Most production wing boards have your construction at best (a lot have wood or only cloth), so good to know how it lasts!

Did you route away some foam in the core to fit the sandwich or did you just laminate it on top?
like mark said, everything needs to be bonded 100% with the foam or delams will happen. So i'm a bit worried that I won't get it flush (considering it is 1cm thick) and as a result, when doing the "top" laminare", the cloth won't stick properly and thus the board will start to wear sooner!

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NicoDC said..
Most production wing boards have your construction at best (a lot have wood or only cloth), so good to know how it lasts!

Did you route away some foam in the core to fit the sandwich or did you just laminate it on top?
like mark said, everything needs to be bonded 100% with the foam or delams will happen. So i'm a bit worried that I won't get it flush (considering it is 1cm thick) and as a result, when doing the "top" laminare", the cloth won't stick properly and thus the board will start to wear sooner!

I put the d-cell (1/4", 6 mm) on top of the foam, and sanded down the front for a semi-smooth transition. No routing involved. I did not bond 100% to the foam; at the edges, I had to use some PU glue (Gorilla) and clamping, IIRC. After 110 sessions, the board developed a bubble on top. It seems to be between the foam and the sandwich. I guess I should have put a relieve valve in. Can't open it up to repair because it's still in use every windy day. Since the d-cell I used was much thicker than what's usually in boards, and the bubble is in front of the standing area, I am not too concerned. This sandwich still has a ton of structural stability. It's almost like an "air inside" board . A thinner sandwich would let more energy through to what's underneath.

I think delaminations of the top glass are worse, because you get more direct impact on the foam underneath. It's worst with styrofoam directly under the glass, since styrofoam has so little impact resistance.

I'm not sure how your PU foam compares to divinycell. It is possible that divinycell has better mechanical properties. It bends a little bit, while PU seems stiffer and more brittle. If you think you'll be using the board you're building for a long time, it might be worth getting some.

Maybe look at the techniques that these guys use:
thewoodbuddha.blogspot.com/search?updated-max=2017-07-06T14:25:00-07:00&max-results=7&start=6&by-date=false&m=1

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boardsurfr said..

NicoDC said..
Most production wing boards have your construction at best (a lot have wood or only cloth), so good to know how it lasts!

Did you route away some foam in the core to fit the sandwich or did you just laminate it on top?
like mark said, everything needs to be bonded 100% with the foam or delams will happen. So i'm a bit worried that I won't get it flush (considering it is 1cm thick) and as a result, when doing the "top" laminare", the cloth won't stick properly and thus the board will start to wear sooner!

I put the d-cell (1/4", 6 mm) on top of the foam, and sanded down the front for a semi-smooth transition. No routing involved. I did not bond 100% to the foam; at the edges, I had to use some PU glue (Gorilla) and clamping, IIRC. After 110 sessions, the board developed a bubble on top. It seems to be between the foam and the sandwich. I guess I should have put a relieve valve in. Can't open it up to repair because it's still in use every windy day. Since the d-cell I used was much thicker than what's usually in boards, and the bubble is in front of the standing area, I am not too concerned. This sandwich still has a ton of structural stability. It's almost like an "air inside" board . A thinner sandwich would let more energy through to what's underneath.

I think delaminations of the top glass are worse, because you get more direct impact on the foam underneath. It's worst with styrofoam directly under the glass, since styrofoam has so little impact resistance.

I'm not sure how your PU foam compares to divinycell. It is possible that divinycell has better mechanical properties. It bends a little bit, while PU seems stiffer and more brittle. If you think you'll be using the board you're building for a long time, it might be worth getting some.

Thanks for all the knowledge!
it's biblical

I can't lay my hands on d-cell but the PU sheet I have is inferior to pvc from what I understand, altough 1cm pu will be stronger than 3mm pvc.

what's the fibre layer you used under your laminate? Sounds like a lightweight layer that broke and as a result, the delam happend.

110 sessions is mad, hats off. That's as much as a production board during rental for 2 summers. No doubt, yours is in better condition!

As long as the water stays out, you should be fine!

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NicoDC said..
I can't lay my hands on d-cell but the PU sheet I have is inferior to pvc from what I understand, altough 1cm pu will be stronger than 3mm pvc

A problem with PU vs. PVC could be that PU has much less elasticity. But that's just a guess based on what the stuff feels like when I handle it. PU cannot be too terrible - the first board I built (ca. 1980) had a PU core that was just glassed over, and I used the board quite often for at least 4 years.

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NicoDC said..
what's the fibre layer you used under your laminate? Sounds like a lightweight layer that broke and as a result, the delam happend.

Possible, but very unlikely. Without sharp impact, fiber glass does not break, and the delam seems to have happened between the foam and the d-cell. Much more likely that there was not enough epoxy. I have seen a full bottom delamination on a slalom board where exactly that happened, as I saw when I repaired it (used it as my first foil board afterwards). I had bought the board 3rd hand, and got more than a hundred sessions on it before it started sounding like a huge drum when hitting waves, so no complains. Got another 100+ foil sessions on it after gluing the sandwich back down.

I did another delam repair on my freestyle board. This one was on top, and the cause was that the inner foam had been crushed. The entire sandwich was still intact. Fun little project to see how different repair methods hold up (PU injection did not last long if the core is crushed; the crushed foam needed to be removed completely). But again, no damage to the fiberglass.

So all the plugs and the foil box are in. Sanding everything flush now, next is spreading on some spackle to hide mistakes and then it's time to start on the bottom lam.
to sand everything flat without messing up the core, i use the failed glass layer as a guide. I can now sand down till the glass is almost gone and peal it off later. This is much better than fixing bumps afterwards with thickened epoxy or messing up and sanding into the eps core.

used pu to reinforce the masttrack, would've been better to also do the footstrap plugs like that.
About the stance I'm not to sure.
for foil cruising, having them slightly wider is nicer but for jumping you'd want them on the centerline.
I'll be trying both and might come back on that later.
Depening on the placement of the back strap, the frontwing will be right between the straps or slightly more forward (gives more pop)

Yesterday was hot enough, no wind and no rain, a perfect day during fall so a perfect day to do some board building!

Bottom lamination is done:
- 200gr of twill fibreglass (of much better quality than last time, it sas stronger and draped around corners better)
- 300gr UD cabon stringer + 3x 200gr twill carbon patches over the box
- 200gr of twill fibreglass
- about 700gr of epoxy if I'm not mistaken

used a roller to spread out the epoxy and then a big cardboard squeegee to push out any air bubbles and to press in against the core.

Did cuts in the cloth at the back corners and wrapped one on top of the other.

came back this morning cut along the tapeline, which went pretty good.
next time i'd be using colored masking tape though! The yellow one is harder to trace under the glass.
only few tiny spots needed to be sanded back.

just as I finished this morning, the wind and and rain kicked in!
i'll be back to share info on the deck lam when it's board building weather again.

Hopefully not a silly question but is the PU block you used for the mast track reinforcement the same as the PU used in surfboard blanks?

Not a silly question :) Yes it is, but probably a lighter PU than the one I used with a lower density and less strengt. PU can also vary a lot in quality from one manufacturer to another.