I’m really excited for you boys. And very anxious for a ride report.
What is your definition of a small wave?
Waaahoo. Gdaddy wanted a foil for micro waves and that’s where I’ve started this thread to help him foil on the slightest of waves. Imagine you’re learning to surf. It’s a sensible place for anyone to start something new.
But with a few mods you can soon take a similar foil out in head high hollow waves but you need to learn how to foil first otherwise it’s a recipe for failure.
The best waves are gentle sloping crumbling waves with a long shoulder. Certainly take a few waves prone to understand the balance back and forth and side to side. Take the time to learn how quickly it lifts and how to handle it. It’s not hard but build on that and you’ll find where you’re happiest. You’ll quickly get the muscle memory to ride it without thinking.
It’s taken me 11 years to progress and learn and I’m more confident and feel safer on a foil than a shortboard.
It’s a completely new world.
I’m looking at these blades as fin area and drag while paddling and when engaged laterally. So I’m starting out with 3"x 8", which is 24"sq per blade x 4. That’s a lot of surface area when engaged laterally even if only 1/3 of the strut area is below water. So I don’t see any downside to cleaning it up other than the time involved. I’m using a 1/8" G-10 core because I got it for $2 (offcuts that were sold by the pound) and I’m using the 1/8" aircraft ply on each side because I just bought a panel for making fins on the other board I’m working on so cutting off a couple pieces for this project only amounts to $5 or so.
I want the struts to be narrow, but have some resistance to flex and twist without being dead like a piece of aluminum. I glassed one side of the G-10 panel yesterday and am doing the other side today.
I did spend $6/ea for (4) 8.5" Bahne boxes which is actually cheaper than FCS plugs or Future boxes - and way stronger. So by the time I’m done I’ll be at about $50 when including the epoxy. And as we all know, good fins (or struts) have a long usable lifespan. Besides, I’ve got more time than common sense.
Thanks, we have plenty of days will slow rollers that really never break cleanly. I have an old Boardworks 9’0" that I could operate on that would be fun to use on those days.
That’s a perfect combo.
Ride report, and where I went wrong.
Took it out in knee to waist high chop affected, weak swell.
As a belly board, got a couple of short rides, must have got some lift as felt moments of increased speed and a very twitchy side to side feeling . Easy to over correct while experimenting with balance.
Where I went wrong: my usual board is a wide 8’ mal. Going to a short board just made it so much harder to catch waves, and I think that in these conditions my wave count on that short board was always going to be poor.
I’m thinking on the mal I would have easily caught waves and hopefully the foil would kick in then I can worry about that.
Plan B: Will get another set of fin plugs and put them on the 8" x 24" mal. See what happens then 
SGO, well done. Sounds like you’re on the cusp of getting it.
As you lift the nose slightly you’ll notice no noise or board chatter and that reduction in drag translates into speed.
Much like a bicycle, the balance kicks in as you get faster.
Would not the surface area contributing to lift be to sum of the board and the foil until lift off?
All the best
Yes Greg, there’s initially a huge amount of lifting area to begin with. On a HPSB I think there’s about 1000 sq in on the hull but Amazingly the small foil area of around 250 sq in is able to lift so efficiently.
Part of that lift is that the foil is submerged and exposed to the rising water of the wave face. The other side of the foil is exposed to a negative pressure because the foil is so large and when you change the AOA, that huge difference in pressure lifts the foil.
So the foil is both pushed up from beneath and and pulled up from above.
Sometimes if you’re heavy or the waves are really gutless the foils going to struggle a bit.
Really big waves are not my forte but I can see that with some R and D Surf Foils for places like Pipeline would be ultra refined hi tech ribbons of Carbon Fibre and able to make very high speed surfing possible. Where that then leads is anyone’s guess.
So what happens when you use shorter struts? What’s the minimum length you’d recommend for a beginner?
The strut length gives you a margin of error to control the vagaries of power, AOA and control.
Too low and you’re surfing, too high and the foil is planing.
Initially I used 12 inch struts but after a few months went down to 8 inches and that’s good length once you’ve got it tuned in.
I’ve gone down to 5 in struts and that allows the board rails to come into play on cutties.
Initially the foil sup guys came out with 3 ft masts and they’ve quickly dropped down to 24 or 12 in but they also do a lot of the Huntington Hop.
For an absolute beginner 8 to 12 gives you plenty of play
I’m ready,hope to get it in the water soon but it won’t be this weekend. This is a board I customized a few years ago,for an earlier attempt at standing up,It’s not an ideal shape for catching waves but I spent a lot of time on it because I knew it might come in handy someday ,WAAYY over built but that’s just how I roll lol.
,the superstringer that I built into the board holding the 24 inch slingshot mast makes it surprisingly rigid for a single mast.
The longer mast is because I want to try it with a kite and behind a boat and the added height is necessary…
It’s neither simple or cheap but it IS homemade enough for me.
Bullet proof.
All the best
While my ideas are unique , there are lots of ways to foil, some of them are very technical with precision parts and others make foils from bits of pine with glass but they all achieve a similar result. And you can choose between any number of struts or mast arrangements.
The higher the tech the higher the cost but it also returns a much more sensitive foil but you’ll always need a wave to ride even if it doesn’t break.
Unless of course you put an electric motor on a foil which can seem to be surfing version of blasphemy on top of heresy.
But it’s possible.
My wing is glassed and my struts are 70% done, I just need a little more work on the foil. The G-10/Aircraft ply combo is solid; they won’t be twisting. I think I’m going to mount them a bit wider apart, like 9" or 10". My test mule board is 22" wide. If the wider “cluster” makes the turning too sluggish then that’ll be my answer.
Gdaddy, I think widening the struts is a great idea for improving stability.
The reason I chose 8 inches apart is that a 16 in wide foil sit neatly under a shortboard and with the struts set at half that distance apart there would be approx the same area of foil inside the struts as outside so you could try a wider foil.
2nd session
After my first attempt I thought I was laying pretty far forward, while belly-boarding, so perhaps I should move the centre of lift forward?
So I turned the foil around to have more area at the front, and shifted it forward 50mm as well.
Not sure if it made much difference, but I did get a short ride on a clean face with the board up in the air 
Unfortunately the end wipe-out, nose first, resulted in some damage. This was in deep water, so I didn’t hit anything.
Anyway; back to the drawing board!
At $10 in materials and 30 minutes of foiling/glassing per wing, busting one is no big deal.
When you did get it up did it still feel tippy to you?