the big patch was added at the same time as the main lamination, better bond. I added another one in the middle to flatten a bit the area between the tracks and add a bit of strength, not sure if the extra strength is needed. the peel ply is to get a smooth surface that requires less sanding.

it is just under 5kg. now it's my backup board, I much prefer riding my downwind style board, a bit more volume, longer and quite narrower... much better for the light wind we get here :)

exactly 2kg.

​​@@matshape Cool! So I guess a 137cm board will weigh +40% = 2.8kg ? What are the dimensions of your board?

​@@vim55k it's 90cm long, and a bit less than 40cm wide. so 137 cm would be +50% length, but as the boxes and reinforcement patches are heavier , your math is correct.

Check out my latest video, that's exactly what you need :)

@@matshape yes. I watched that video and forgot . I will go in comments there and ask about the weight

thanks, added.

​@@matshapeawesome! Thank you!

clear after the filler, but before reinforcing the parts that needed it to see better if clear was enough or more reinforcements was needed: sanded is hard to see if the shape is blended well, with clear, the shine is the same as the board. like this I can mix single batch of resin when reinforcing and add thickness to other spots if needed (after sanding off the clear of course)

hard to say, but the polystyrene shaped would be ~800g, the fiber would be ~3/4 of mine on that board considering the shorter length, so if you try to keep it very light, 3.5 / 4 kg should be doable ...

sure, Drop me a mail (see contact section on my profile) I can send the fusion360 archive.

congrats... but you could have told the rest of us about wing foil and downwind boards :)

lot of things you learn as you go... but main one i often forget and regret after is thinking i'll fix a small defect at a later step... this never works. If your rail is not fair, you'll sand through the lamination when trying to fix it. result of each step should be as good as you can make it before moving to the next.... Good luck!

@@matshape Hi Mat. Instead of the 300g bi-axial carbon fiber, do you think other weaves will do the job? Thanks!

weave type doesn't really matter for what we are doing... our designs are not optimized enough and the load we apply varies too much for weave choice to bring the board from "strong enough" to "too weak" it's more about having a sound structure inside the board to transfer the load between feet and foil. I'm convinced i could get away without the 300g reinforcement... until something else goes wrong. Recently a jetski hit my board at full speed on the water and broke the bond between the HD foam and polystyrene, so my boxes were moving, but thanks to the thick re-inforcement on the box, the board stayed waterproof and in one piece, not rideable, but fixable.

So far so good, but it was summer time (40+ Celsius everyday and crazy humidity) so not great to practice foil paddle up... I'll use it much more soon. I expect to ding it at some point, but easy to repair. I guess with slightly thicker hotcoat it would be a bit more ding resistant. Also, I confirmed it's not ideal for winging. I don't need the extra volume compare to my previous board to take of in very light wing, but the extra length interfere with the wing during some gybes.

@@matshape i was inspired by your build to make myself my first board. i will use 450g carbon for the standing areas. overall 200g carbon and some 100g fiberglass on top overall. i hope this will get light but stiff enough for the lengt of 188cm and with of 50cm. a flat carbon stringer over the middle under and topside. do you recomend something on it?? tipps thoughts? (sry for my bad english ;) )

@@gamma8283 no need for carbon stringer on thick boards like this Good overlap on the rails is enough. your plan sounds good, but don't forget to also heavily reinforce the boxes.

@@matshape my Plan is to integrate some standing airex plates between the box and the deck inserted with fiberglas and overlap it to the deckside for more strenght.

Gorilla glue, but be careful to avoid where the hotwire will go, it can't cut through dried gorilla glue.

thanks, 4.6 kg before adding the pads...

thanks, yes, i can send the templates i used. drop me a mail (see contact section)

@@matshape i send the mail!!!!thak so muchhhhhhhhhhhhhh!!!! <3

I designed that one using a few commercial models outlines as inspiration. drop me a mail (see contact info) and I can send you the dimensions I used to make my templates.

now it's new, it's back to be worth something :)

You're not worth anything

yes, that's enough overall, just the tracks and standing areas needs more reinforcement. Note that this is quite light, so it will ding more easily... but if you make boards, a quick repair from time to time is not very hard :)

That’s why I do alcohol wipe before epoxy or clear coat … but I discovered that alcohol dissolves scratch repairs done with paint pens… lesson learnt :)

removing the need for a vacuum setup, no epoxy mess on the floor, limited shaping with extensive use of the hot wire.. overall simpler :)

Should be doable, I think I saw some like this on some forums ...

thanks, yep, that should be precise enough :)

I guess proceeding that way will act like a lot of stringers, but that's not really a concern with those thick boards. The vent is needed because i use EPS that has lots of void, so in the sun (especially for black boards) the pressure rises quite a lot inside. I'm not too concerned by the skin delaminated from the EPS as the resin penetrate in teh EPS, but the skin breaking chunks off within the board.

@@matshape Exactly. With layering we reduce a volume which can expand, and so top and bottom coats move less and do not break ESP up (it can happen as inside ESP, as well us just below a surface like a delamination).

I see, that kinds of insulate them, but board volume stay the same, I guess the glue lines help keeping the skins together. interesting concept

not sure if google translation is correct... board is ~115L., and I''m ~72kg, so it floats pretty well, a bit unstable because its very narrow, but the foil help :)

thanks! i got mine from amazon, look up vacuum storage for clothes. below 10$ for the manual pump and a few bags... pay attention to bag sizes, and if you feel like going to electric pump, be careful, there are 2 types: the short round wide are useless to make any level of vacuum and there are some longer skinnier ones that are usually more expensive and those produce proper vacuum... but for small board, hand one does the job easily.

@@matshape 🤙🤙

I would also like to add footstraps, where would you recomend placing them?

thanks! epoxy and polystyrene are local from UAE, quite expensive to ship internationally. Carbon, glass, HD foam from easy composite, and boxes from Aliexpress. Glass works fine too, and if it's your first board it's much easier than carbon to work with. Just make it a bit thicker to be sure. no need for a stringer if the board is thick enough, but you need the reinforcement linking the boxes to the deck. For straps, I'm not using any anymore, but especially for a prone board, I'd copy the placement on a existing board.

@@matshape Thank you!!

please develop ?

I replaced that one a few month ago, this one is my spare for friends now. New one has a continuous loop all around, slightly convex on the inside, with double layer of tick foam in the middle, a back slightly longer to cover my sides better. To add a phone, you might have to add a harder plate to keep the harness from trying to ben your phone, may be a camelback or something like a sling would be more appropriate. good luck!

yes! in europe and US for sure... but not where i live, and shaping the board is most of the fun :)

@@matshape Ok but you will be finding foam dust everywhere for a very long time. It's also very irritating and bad for your lungs. Have fun !

with a separate workshop, yes! definitely the way to go... but as mine is a bedroom with a common wall with a neighbor, I'm trying to minimize the noise as much as possible.

good luck!

I think the hand pump gets less vacuum than what you can get with an electric one, but you don't want full vacuum anyway, that would risk crushing the polystyrene. Vacuum cleaner works to remove most of the air, but it usually doesn't create a vacuum tight enough.

@@matshape what i saw in a surfboard factory similar to firewire (all epoxy boards) is they use a rocker table (curved table) and vacuum bag goes around table as well as board this way they can make varying degrees of rocker (curvature) without needing to shape foam to create. foam is malleable but cured glass/epoxy determines curve.

@@silasketgaskets8709 yes, rocker table definitely work too, as I was doing a single board, I put the rocker in while gluing the stringers... table is definitely better for doing lot of boards

cheap by not using vacuum, using glass instead of carbon would have save less than 50$

no wet out of the blank first, I never do that. Especially that board as the EPS is quite dense, so it won't absorb much resin anyway.

@@matshape thanks for the quick reply! Was it 1# EPS?

@@Davids-eq7ky oops, my bad, i thought that was the last video i uploaded for a pumpboard. yes, for this one, it was ~1lbs/ft3 EPS. here my logic for not filling the blank first is more that as i'm wetting the fiber on a table, it limits the epoxy use and the blank will not absorb any during the lamination process. only risk is to have some pin holes when the resin is pulled from the fiber into the blank, but as i'm doing fill coats after, it doesn't really matter.

@@matshapegot it. I usually wet out on a table but use vacuum. I’m very tempted to stop using it to save on materials and time. You haven’t had any issues with no vacuum for this board?

@@Davids-eq7ky no problem at all, you just get a small weight penalty as excess resin is not taken out in the peel ply/breather, but if you're careful when wetting on the table it's not too bad. You also need to avoid radius too small on the rails to avoid the fiber to lift.