XPS Surfoil Build 6 x 18 x 40ltr x 3kg

[Dontsink]

My first full board build!
Just surfoiled it this morning and it did not self destroy, to my relief
Paddles great and feels very nimble for a 6 footer.

Winged it in very fluky,light wind and it was incredibly stable vs a 5 footer of the same vol.The lenght really settles it down plus it allows for a very easy Cowboy to Stinkbug start.

-6 x 18 x 40ltr x 3kg
XPS blank with chambers
Bottom 205 gr + 80 gr/m2 carbon + Usual foil box patches
Top Carbon/Innegra 150gr + 100gr Carbon + standing area 200gr Innegra
Futures foil boxes with flanges removed.
2 Carbon tube (1cm diam /1mm wall) stringers on bottom  connected to boxes.
8 vertical Carbon tubes (25mm diam/1mm wall) from deck to boxes.
4 Carbon "strings" (about 3mm) tying deck to boxes.
No HD foam.
Vac bagged at 4-7InHg.

No hotcoats,spackle or filler...add my sinful hands and dubious techniques and she looks really,really fugly up close.

But i am happy with the shape,function and weight.I think i can go even lighter on the next one, a 75ltr wing board.

My previous surfoil board, a Gong Matata 5.0 was a very slow paddler, short and wide plus the kicktail took away a lot of effective waterline.

This one feels really effortless in comparison.
A 6 footer is a 6 footer,no miracles, but the narrow width and straight narrow tail really make it glide.

[jondrums]

this is incredible!  Thank you for posting the build details.  3kg is awesome.  The Beasho innovation of ignoring pinholes and letting the lamination "breath" is really enabling some interesting builds.

I have been wondering how long until we see barracuda style prone boards.  Any downsides? 

[Beasho]

3 KG is fantastic.  I was surprised it was so light given all the carbon.  Great Job!

I was just yammering with Kyle Pemberton about board designs.  People keep talking about foiling being a game of inches, and millimeters and just incremental improvements. NO WAY!

When a production SUP Foil board weighs more than 15 lbs it is either 1) For Aesthetics 2) Over Engineered 3) Badly Engineered or all 3.  A 120 liter board can be made between 10 and 12 lbs. 

Foil boards require a formidable deck and box structure, but otherwise the periphery should be light and potentially sacrificial. 

Keep us posted on those Cores.  There is some risk of water intrusion. 

[Dontsink]

this is incredible!  Thank you for posting the build details.  3kg is awesome.  The Beasho innovation of ignoring pinholes and letting the lamination "breath" is really enabling some interesting builds.

I have been wondering how long until we see barracuda style prone boards.  Any downsides?

Thanks!.
Well, it is 6 feet long so you have to get used to the nose touching down at a shallower angle than what you are used to.

But i am very happy (and surprised   ) with how it rides overall.

My conditions (Atlantic beachbreak ,bumpy,closeout,lots of  paddling) have made my surfoil progression really frustrating.Catching lots of waves and getting in the open face early to ride or pump out is key and this board makes it a lot easier.

[Dontsink]

3 KG is fantastic.  I was surprised it was so light given all the carbon.  Great Job!

I was just yammering with Kyle Pemberton about board designs.  People keep talking about foiling being a game of inches, and millimeters and just incremental improvements. NO WAY!

When a production SUP Foil board weighs more than 15 lbs it is either 1) For Aesthetics 2) Over Engineered 3) Badly Engineered or all 3.  A 120 liter board can be made between 10 and 12 lbs. 

Foil boards require a formidable deck and box structure, but otherwise the periphery should be light and potentially sacrificial. 

Keep us posted on those Cores.  There is some risk of water intrusion.

You and many others here have been my inspiration
A big crash would get water in the hollows, at many points it is only 1.3cm foam.
The chambers are all connected for pressure venting and (hopefully) water evacuation if it comes to that.
Would need to drill the nose chamber open and open the valve at the tail, then gravity or force air through.

I tried lots of ideas on this one, many copied from you guys.

The overengineered foilbox is an attemp to remove loads from the foam (will mush out eventually) and  the flat bottom carbon lam in front of the foilboxes (flat carbon is not great in compression).

[jondrums]

Did you weight during the process?  I'm wondering how much of the total weight is the hollowed out blank, boxes, stringers, and carbon tubes versus how much is the external lamination?

[Dontsink]

Did you weight during the process?  I'm wondering how much of the total weight is the hollowed out blank, boxes, stringers, and carbon tubes versus how much is the external lamination?

Yes i did, that was kinda depressing after all that work .
The holes took the blank from 1600gr to 1400gr , 200gr duh!.

Sounds ridiculous i know...but still it was 15% of the blank weight. Every gram counts.

With a bigger volume board you can take a bigger percentage out leaving the same margins to the skin and of course the total will be bigger anyway. Maybe saving 500gr for 80ltr board is possible i think.

I think the foilbox is very light.
It added 400gr before bottom lam but that includes glassing in the leash plug and Gore vent.So maybe 350gr?.


Another factor is the Spread Tow carbon,it sucks very little resin.

And of course not levelling,hotcoating etc...

I think next one will have lighter layup on bottom for sure(180 to 200gr?), on top the same.

** Of course if yo go CNC you can save even more on the blank...hexagon chambers and more even distance to skin.

[jondrums]

1400g for drillium blank
400g for boxes, leash plug, gore vent. (why install a gore vent if the entire lamination can breath???)
1200 for the lamination - and you think you could take maybe 200g out of that

Thanks. I bet you could get a lot more out of that blank if it was CNC cut on the inside - maybe 2-300g more.

Freaking exciting that a 40L board could maybe get to 2.5kg

[Dontsink]

1400g for drillium blank
400g for boxes, leash plug, gore vent. (why install a gore vent if the entire lamination can breath???)
1200 for the lamination - and you think you could take maybe 200g out of that

Thanks. I bet you could get a lot more out of that blank if it was CNC cut on the inside - maybe 2-300g more.

Freaking exciting that a 40L board could maybe get to 2.5kg

With chambers the Gore vent is a good idea i think.
Leave the board in the sun a few minutes and the air inside is going to expand...the chambers are sealed inside the blank so they will not breathe through lam pores and if they were  it is hard to predict how much out flow there would be.
Then the board would contract in the cold water and suck air inside through those pores...i prefer to install a Gore vent if you use chambers.And connect them.all.

But a guy on FB made his with chambers but forgot to connect them before lam (100l board with bigger chambers).No vent and no issues so far he reported.Maybe it is not necessary as you say.

For 40ltrs i do not think i could go much lighter, a bit under 3kg but not 2.5.

For 70-80ltr wingfoil the goal is 4 to 4.5 kg.
Custom EPS boards are 5 to 5.5 so waterproof core and 1kg lighter woukd be very good.

More pics than you ever want to see of the build here :

https://mega.nz/folder/oexSgYyb#OC23F-saNkSy0twtbeMkpw

This EPS mod might be worth experimenting with,looks very promising:
https://www.facebook.com/groups/232666917793846/permalink/949133616147169/

[Dontsink]

This is how fancy you could get with CNC & Hollow cores.
Not much info about this board but the hollowing is next level.

[surfcowboy]

Thx for posting all this!

I'd think if you don't seal the skin that much you could get away without a vent. But not a bad idea to have one anyway.

Also, your work taught me this, don't chamber, or if you do, just cut blocks out of the nose and tail. I'll bet we could get 200gm just from cutting pieces out where you won't be standing. This is how we all learn. Thx for sharing this.

I would like to ask some of the more experienced builders if the carbon over innegra will be more likely to break. Would innegra on top be better? Yes I know it's ugly. Haha.

I think I want to do one of these out of glass just to make it fast and cheap for testing. But first I gotta go paddle a few boards. Heading out soon to test a buddies DW SUP!

[Dontsink]

Cutting big blocks is easier yes,  but everything has a price i think.
The bigger the "holes" the more compression,flex and torsion resistance you loose in the blank.
Cut some identical blocks of XPS ,chamber them in different sized holes and try flexing,twisting or standing on them.

For my "tests" the walls between adjoining cells became almost mushy at about 5mm thick so i used 8mm minimum between chambers (25mm diam cylinders) and 1.3mm minimum from chambers to skin.

But all this was hardly scientific testing, more like how it felt after some pottering about  with it.
So do your pottering and post please

EDIT:
The innegra works better over the carbon,from what i have read.But it was 150gr and i wanted to lam it first with the  aid of spray glue,it really makes it easier for me (inexperienced) to get the rails,nose and tail in place without unraveling or lots of creases.
The carbon was lighter and easier to lam normally.

[surfcowboy]

Thx man. And yeah we all can test a piece of this and figure it out.

I'm going with Charlie Grey Special and laying up glass with carbon reinforcement I think. 4oz over 6 oz (6 only at ends) with strips on the rails to take the paddle whack. Might find some innegra for that. Hmm.. 

[Dontsink]

https://www.instagram.com/reel/CwqB7J4rAVR/?igshid=MzRlODBiNWFlZA==

Loving this board!.
I am finally getting some progress (and lots of fun) in this surfoiling thingy.