Topics

1

The Shape Shack / Wetting out S-Glass Efficiently

« on: January 19, 2024, 11:08:13 AM »

When wetting out fiber with Epoxy Resin there is an ideal ratio of

• 60% by weight fiber
• 40% by weight of resin

to achieve maximum strength to weight in a hardened matrix when dry using a Vacuum bag.

I have been able to achieve this ratio with Carbon.  Wetting out the carbon on a table, using more Resin than necessary ~ 120% the weight of the fiber, and then vacuum bagging.  The end result comes out very close to 60% fiber / 40% resin. 

When I am wetting out the S2-Glass I am getting more like 45% by weight Fiber and 55% by weight Resin. 

I am wetting out on a table, with plastic.  It seems like the S Glass doesn't wet out as easily, sucks up more resin, but maybe just takes more time to spread.  Then the Vacuum is NOT taking out all the expected Excess resin.

Any Advice Appreciated.

2

General Discussion / Winner at Mavericks A Stand Up Guy

« on: November 22, 2023, 01:15:19 PM »

Go Haley Fiske!

Opening day at Mavericks 2023-2024 season was won by a Stand Up Guy!

https://youtu.be/yNTWXmDDYZs

3

The Shape Shack / Ultralight Board II – SUP Foil Bumblebee

« on: July 16, 2023, 11:02:49 AM »

My desire was to replace one or both of my 6’ x 30” x 115 liter Jeff Clark board and my 7’ 4” x 31” x 125 liter L41.  And to make one of the lightest SUP foil boards in the world.

And this is the Bumblebee 6’ 9” x 26” x 5” x 115 liters @ 11 lbs (5.0 kg). 

The construction was from 1.5 lbs/cu. foot XPS waterproof foam.  2 x 2” Layers from Home Depot.  The top layer was 1.8 lbs/cu. foot 1” thick.
The ‘Cassette’ standing area was reinforced with 2 layers of 5.8 oz carbon in a T-orientation 38” long and 24” wide by the base.  The top of the Cassette, the dance floor, is 3 layers of 5.8 oz carbon oriented in a 30-, 60- and 90-degree bias to add significant stiffness to the deck patch.

The nose and tail, ~ 18” each end, were covered in 2.2 oz Kevlar.  The objective was to keep the board as light as possible in the ends.  The Kevlar on XPS is very puncture resistant.

The side walls were 44” x 7” of 3.7 oz S-Glass and I added 48” x 2” @ 3.7oz S-Glass rail guards for paddle protection.  The top rails were also overlapped by ~1.5” with 2 layers of the Kevlar.  One layer from the bottom and one layer from the top. 

The final build came out to 11 lbs with pads and Strap making for an HL (Hectoliter) Factor of 9.6 lbs / 100 Liter. 

HL Factor = 9.6

https://www.youtube.com/watch?v=FmrIqHGcqqM   

4

Foil SUP / Freefoil Pump Forever: Latest High Aspect Solution

« on: July 09, 2023, 11:18:12 AM »

Higher aspect is more better.

Essentially an ultra high aspect design with 2 struts for stability. 

Gliders have gone as high as 20:1 so our hydrofoils have a long way to go.

https://youtu.be/WfJbF0xkUOY

5

The Shape Shack / Rail Structure and Impact Resistance

« on: April 08, 2023, 09:57:52 AM »

My ultralight board has shown its first signs of wear on the rails.

Specifically the Port (Left side) rail.  I was surprised it was ONLY one rail until I realized that was the side I normally crawl on the board.

The board is XPS foam, which means it has a compressive strength significantly higher than EPS foam.  Example 15 psi vs 4 psi. 

Structurally it should be more sound, but I found cracking of a rail that was a combined 6 oz Carbon and 4 oz S-Glass.  Granted my rails were very sharp.  Probably less than 1/4" radius, or half inch diameter (problem #1).

My standard SUP EPS boards have not worn on the rails like this board.   

So is it

1) Simply how hard the rail was?  Make it a 1/2" radius (1" diameter), or 1" radius (2" diameter) curve.

2) Bolster the rails?  I don't think carbon works well on the rounded rails.  I could use 1X 4 oz S-Glass and then a 2" Kevlar strip. 

Other suggestions?

Note:  Because this board is XPS I don't care about dings or water intrusion.  I can also just modify the rail after the fact, use a router and just re-route a larger radius rail, and then re-laminate.  The photo shows cracked rails, sanded down, then modified with 2" Fiberglass strip covered with 1" of Kevlar fabric Gorilla glued on to rail.

6

The Shape Shack / Maximum Displacement Hull Speed

« on: March 12, 2023, 01:11:46 PM »

Researching speed profiles for the next SUP Foil board build I came accross the formula for Maxiumum Displacement Hull Speed:

1.34 x (Waterline in Feet) ^ 0.5 = Water Speed (knots)

These formula have been around for 150 years. 

There is a caveat that a LONG THIN Shape can exceed this maximum, but this is a starting point, basically like shooting par on the golf course.

7

Foil SUP / Balancing on Barricuda Style Boards

« on: March 05, 2023, 10:48:16 AM »

I have been riding my 21" wide x 7' 9" x 6" @ 128 liter 'Sailfish' board for 3 weeks now.  When I first got on the board I would paddle out sitting on the board, or kneeling.  Then get to the break and hop up to catch waves.  In waves or downwind I would last ~ 2 minutes with my back bent @ what felt like a 90 degree angle before I would be gassed out and likely fall it.

Fast forward a few days ago.  I tried to downwind in 15-20 mph of wind, hyper chop outside the harbor, open ocean, in Half Moon Bay buoys 14 feet @ 10 seconds.  I spent 2 hours and stopped counting my falls after 30.  Caught ZERO waves, and ended up paddling 2.6 miles humbled.   

BUT a small part of me realized that I was still able to stand in Chop Factor 9 / 10 for 2 minutes on this board.  3 weeks earlier I would have only lasted 10 seconds in this horror.

The next morning I went out, wind dropped briefly to <8 mph, waves dropped to 10 feet @ 8 seconds.  I paddled out, and hopped to my feet.  I could stand somewhat comfortably with my feet at a 45 degree angle. 

I made the 8 minute paddle to the break, turned caught a wave rode 400 yards before losing the bump.  Dropped off foil, paddled back out, caught another 220 yards, then 400 yards, then 690 yards.   AND I had dry hair.

4 consecutive waves without falling in.

OMG!!!!!!

I eventually had to sit down on the board to rest. 

You can learn to stand on these boards!   6 months ago when I was trying other boards like this I could only comfortably stand in very clean conditions.  I thought there was NO way to comfortably stand up and paddle around on the Barracuda style boards.  No more.

Similar to using BIG foils, if you can't catch you can't fly.  I will add, if you can't stand you can't catch. 

Hopefully this motivates others to keep trying.  Please share any similar perspectives or advice on standing on these narrow boards. 

8

The Shape Shack / XPS Board Building Advantages vs EPS Foam

« on: February 05, 2023, 06:00:12 AM »

The following are observations from building a board with XPS foam. These are the benefits:

•   The foam has a compressive strength of 20+ psi (pounds per square inch).  This means that the foam can handle a full 100% vacuum.  This is significant because it allows for full vacuum pressure (always slightly less than 15 psi). 

•   The foam is structural in nature, much more than EPS which can only handle ~ 3 psi. 

•   The foam is closed cell and therefore waterproof.  This means that MUCH less care needs to be taken with the foam to
1) Prevent dings
2) Repair a ding when it happens
*There may be NO need to repair dings because the foam will not absorb water. 

•   At a full vacuum it is possible to attain the optimal ratio of Fiber to Resin.  This is 60% Fiber and 40% resin. Boeing shoots for 70:30 with its aircraft grade fiber but does so with incredibly high pressures.  The pressure applied during curing is key to both:
     o   Maximum Strength
     o   Lowest Possible weight

•   An XPS foam blank can be laminated, built into a board, then torn apart and re-shaped.  This has not been tested, but when skinning the lamination the material surface remains clean, and relatively smooth.  In theory you could take a blank, and remove the rail lamination.  Then ADD or Subtract rail area and re-laminate. 
     o   Think Sustainability
     o   XPS – Is also 100% recyclable

•   Because the foam is waterproof the lamination layer does NOT need to be waterproof.  Most surfboards have between 2 and 8 lbs of additional lamination, gloss coats and PAINT to seal the EPS (water absorbing foam) from any of 100’s of potential pinholes in the structural fiber matrix.  This can ALSO make the board look good.  But the brittleness of these coats MAY also lead to more dings.  And who wants a board that has a 5 lbs dumbbell added for waterproofing when it may not be necessary.
   
See this for a comparison of the foam properties.  There have been some mention of delamination, but there is evidence TOO that this may be a function of

     1) Construction technique (for example using a wet lamination vs. Vacuum bag and
     2) Thermal Insulation. 

The XPS has a boiling point of 160 degrees F.  It is also a better insulator than EPS foam.  Leaving a black surface in the sun, laminated to an extremely effective insulation with a low boiling point WILL melt the foam.  We’re working on solutions here. 

https://www.soprema.co.uk/en/article/sopravoice/circular-construction-goes-hand-in-hand-with-xps-insulation?_gl=1*1t2tx9l*_up*MQ..*_ga*MTgyMTY2ODE4OS4xNjc1NjA0MjIy*_ga_XFVVM26VEP*MTY3NTYwNDIyMS4xLjAuMTY3NTYwNDIyMS4wLjAuMA..

9

Foil SUP / Foil Math Wave Size = 2X + 1 and Big Waves

« on: January 30, 2023, 02:22:48 PM »

When foiling the size is multiplied by 2X +1.  This is what makes foiling so exciting.

A 2 Foot day feels like 5 Feet

A 5 Foot day feels like 11 Feet . . . . 
 
During the latest “Eddie Swell” the buoys rose up to 11 feet @ 18 seconds.  Mavericks was crowded with 50+ people.  So Jeff Clark called and said “Let’s go tow foil!” 
I would love to tow in or around the reef at Mavericks but Jeff is pretty staunch about his opposition to wakes when people are paddle surfing.  So we went a bit further North. 

I said “No need to go deep, there is plenty of stuff to catch flying wide.”   And here is where he put me.

10

Foil SUP / Weight Matters

« on: January 24, 2023, 10:27:26 AM »

With all the talk about board lengths, and widths why doesn’t anyone talk

WEIGHT ?

What does it WEIGH?

We need to shed some LIGHT on Weight.  It’s like we’re all hanging out afraid to offend Anorexics. 

As I have started down the path of board building I have been running the numbers on WEIGHT. 
I have realized that the majority of boards are built:

1)   To look good with THICK Paint jobs
2)   To Not Ding
3)   Without Vacuum bags

When it comes to weight of SUP foil boards
•   8 lbs is DIVINE weight
•   10 lbs is DREAM Weight
•   12 lbs is Fantastic
•   15 lbs Average
•   18 lbs Getting Too Heavy

I now look at boards and I see DEAD WEIGHT.  I am starting to believe that even a BAD shape that is LIGHT will be better than a great shape that is TOO Heavy. 

11

The Shape Shack / Ultralight Board Designs

« on: January 09, 2023, 11:05:16 AM »

Let’s Make a Sub 10 lbs SUP Foil board. 

I have run the numbers and this should all be possible.  There are Pros and Cons

Background:
•   Board designs are changing so fast you might pay $1,500 or more and get a board that is obsolete in 6 months
•   Figure out how to minimize the investment in ‘Unnecessary’ infrastructure.  This includes 1) Material 2) Cost and 3) Weight
•   The board does NOT have to last 10 years.  The objective might be to have 30 sessions on this board. 
•   Invest in the Foot area and the TRACKS.  BUT Don’t over index on the TRACK reinforcement.  I have been a Tuttle advocate since Day 1.  For 30+ years Tuttles were the only boxes that wouldn’t rip out of windsurfers.  Tuttles go Deck-to-Deck.  There has to be some substantial material extending from Deck to Deck.  BUT there could be a very light Matrix of foam and carbon rod, with solid top and bottom carbon layer for example that would suitably hold the load for dual tracks.

Estimated Weights of Final boards.  This matrix shows the estimates for a board with:
1)   Dimensions will be similar to a Barracuda shape 7’ 6” x 22” x 6” around 120 liters
2)   XPS Foam:  1.5 lbs per Cubic Foot.  Water Proof and therefore MINIMAL intrusion of water from Dings.
3)   1 Layer of 6 oz of Carbon around the entire board.  Estimate using a 60% fiber to 40% resin ratio.  It will be vacuum bagged.  No final gloss coat.
4)   Dual Tracks will be added.  Ideally 1 lbs of additional weight for the Tracks and necessary structure.

Total IDEAL weight:  8.8 lbs.  It will NOT be pretty.

12

Foil SUP / eFoil Etiquette in the Lineup

« on: January 02, 2023, 07:26:52 PM »

So it has happened.  eFoils and Foil Drive Assists going through the lineup.
 
Where do eFoils and Foil Drives fit in the lineup hierarchy?

First there were SUP’s, then SUP Foil boards and Prone Foils introduced to the lineup and causing varying degrees of UPSET.   This past week it happened at one of the better spots in Northern California.
 
We have been SUP foiling when the waves are gigantic at this protected, otherwise beginner spot, for the past 4 years.  Buoys typically 15+ feet at 18 seconds and Mavericks would be breaking 30+ feet.  The knowledgeable beginners stay away, so the foamies clear out and we will catch waves at the half way point where they soften and the short boarders, or better long boarders are about to kick out at the end of their rides.  Takeoffs can range from 6 to 12 foot faces so its advanced foiling conditions. 

This week I was out and it was big, but not gigantic buoys 12 ft @ 14 seconds.  The long period wraps the point inside to where the beginners sit and there was a pack of foamies well inside.  I was SUP Foiling and could takeoff on 5 to 7 foot unbroken faces 200 yards wide of the pack.  Then I would fly wide into the open, unbroken ocean. 

I turn for a wave and the eFoil Assist guy 20 feet inside of me says “You going?”  Really!  You’re going to power OUT into the lineup and then ASK me, as if you are going to SPIN and go!!!!!!

There has to be SOME UNIFORM etiquette around eFoils. 

I am not a hater, and there are some outer reefs that a Foil Drive Assist would be great but at this spot it was clear that the eFoilers were NOT advanced riders.  They were learning to takeoff deep as opposed to developing good paddle skills and flying wide of the whole world where the entire open ocean would be their playground. 

We have managed to keep the piece as foilers but the locals were yelling at the powered guys. 

PS: For the record there was a guy on a Lift eFoil last week that was totally keeping wide.  Never tangled with anyone, totally respectful, skilled and was having fun.     

13

Gear Talk / iWatch ULTRA the Good the Bad

« on: December 26, 2022, 02:26:01 PM »

I just got an iWatch Ultra from Santa.

I was a bit ambivalent about it but my iWatch 5 could get spotty reception at times and was bad with Dawn Patrol sometimes shutting down sessions.

I am only 2 days in but:

The Good:

• 2 hour surf session running Dawn Patrol only burns BATTERY from 100% to 80%
• The BAND appears to be much more robust
• Initial testing with Wet Fingers seems to work better
• Texting in formerly bad areas now works aka BETTER RECEPTION

The Bad

• Dawn Patrol appears to SMOOTH the speed on Waves with what looks like a running average.  Lowering Max Speed. This eliminates the mini peaks on takeoff and troughs of speed during flight? See data from 2 apps below.  Same Wave Max speed different
• There is now a difference between top speeds on Waterspeed and Dawn Patrol.  With Waterspeed higher and Dawn Patrol reading 15% lower on MAX.
• The band is harder to get off quickly.  Good (maybe) for not losing but more bothersome when daily charging

I am sure there is a WHOLE LOT MORE GOOD so let me know. 

14

Foil SUP / The Tale of Tails

« on: December 07, 2022, 11:29:54 AM »

One of our local FOIL Amigos, Kyle, has been pushing the limits of equipment with a focus on downwinding.  There have been plenty of discussions about front foils but not quite as much about tail wings.  So I decided to dust off the formulas and “run the numbers” on tails and their influence on the LIFT and DRAG of our Foil Systems.

My Conclusion:  Tails Count Twice

In Simple Terms:  The Lift Generated by the Main Wing (Front Foil) has to carry:

Weight of the Person  +  Weight of the Foil board + Downforce of the Tail (?)

In my case ~200 lbs of Person with Wetsuit + 25 lbs of Board and Foil = 225 lbs.
 
Because Tails create DOWNFORCE for stability this Center of MASS sits slightly in front of the Center of Pressure of the Front wing.   The Center of Pressure is typically at the ¼ Chord meaning 25% back from the leading edge of the wing. 

15

Foil SUP / Longer Fuselage for Stability and Pump

« on: November 22, 2022, 09:38:39 AM »

Contrary to the conventional “Go Shorter” on fuselage I am proposing To Go Longer.
 
My objective is to catch More Waves, Smaller Waves and Bigger Faster waves on a SUP Foil.  I have found that BIGGER boards can do all of this better than SMALLER boards.  The challenge with bigger boards is pump-ability.  So in an attempt to match the resonant frequency of Bigger SUP Foil Boards, meaning 5’ 6” – 6’ 0” board in small waves or 7’ – 7’ 6” boards in big waves, we might want to go back to longer fuselages.

I have been using the Crazy Short Axis 644 mm / 25.3 inch fuselage.

Prompted by a discussion on the Swim Missiles thread I called Sam P’ae and had a 45 minute conversation on the benefits of LONGER fuselages for stability and pitch control.  For me this would be most interesting in Big Wave scenarios – Thinking 10 foot faces with a standard Fuselage 784 mm / 31 inches long.
 
Ideally you can use a long fuselage with a LITTLE tiny tail.  Think Flying Wing with a Carbon Arrow for stability.