The FLIPPER

Looking to do mischief with foam and fibreglass one day…

I thought about making a lot of boards into 1 board.

Just a rounded shortboard mixed with a pin tail gun,

and with maybe a shortboard pintail and a rounded longboard added in.

Minimal volume in the pintail and lots more in the shortboards’ tail. And a lot of other variations too.

So what to do… maybe try something in a smaller version and build up.

Having a penchant,inclination, preference, perversion and a touch of fetish for the paipo at the moment, ( courtesy of a separated shoulder ) I found a start point.

Starting with the planshape. I thought of this…

A scalene triangle, rounded all round, but if you FLIP it, you get 4 different shapes.

Not overly pretty I admit, until you flesh it out with a few attractive curves and start turning a thought into an idea and then into a solid design. See next post…

SF.

Now its looking more organic, different WP’s,( as indicated), different widths,curves, math and science all the way 'round.

Accel. curves for manouverability, decreasing curves for hold,straighter lines for drive, same ~ area each side for lift taken from several angled midlines. And taking into account how the 3rd dimension will increase or decrease hold or release.

All the usual stuff but with more to come.

And I thought Id use the ply outline as more than a planshape and use it to make a HWS skin too.

The ply is beautiful Swedish aircraft ply that was used to make WW2 Spitfire planes, amongst others…

I bastardised the ply for my own gain and glued several slabs together but the details of that are boring. The important thing is that per sq. in., its twice as strong laterally, as longitudinally.

SF.

Surfoils-where did you get info about Ply being used in WW2 Spitfire planes?

The Spitfire(and all its variations) was built as an all alloy stressed skin monocoque-no wood in site!

Maybe your confused with the Mosquito twin engined bomber-that had incredibly strong plywood wings that coupled with its slippery shape was an incredibly fast aircraft. Its designers unknowingly at the time also created the first “stealth” bomber, as the wood did’nt reflect the the primitive German radar of the day!

That said-I’m intrigued how your kraft is going.

Hey shifty, only source of info was the dudes at the lumber yard. They said it was for internal bracing/ bulkheads. Thanks for steering me straight tho, I hate being a source of mis info.

Anyway,sanded 2 outlines using all sorts of witchcraft and blasphemy til I was happy.

Every picture makes it look a different shape.

The intention is to have nil rocker but use the rail (outline/ planshape) as the rocker. So it should be as fast as possible in a straight line but with the exaggerated outline it should loosen it up.

Paipos are pretty manouverable anyhoo just because of their size so the outline design came back to being an exercise in blending different rails and tails.

So I sanded down a ply stringer, ~ 3in wide 7 ply, 3/4 in at the round end down to 1/4 in. ( At 3 inches wide and horizontal, is it still a stringer or a beam?)

Epoxied into place on one side.The shadow of the stringer shows the thickness variation.

And then poxied the other skin on top.

So with the 2 skins separated by only the midline stringer, I taped off 2 in strips of carbon and cut down the centre of the tape so that the edges dont fray when I wet them out and lay them up.

The tape weighs nothing and I can sand it off later if its going to be seen.

Now with the ‘flipper’ on its edge, I laid 1 strip per side against the stringer. So with a strip either side the stringer became an " I " - beam, of sorts… or an H - beam…

End elevation.

Chime in if you want or am I being boring ?

SF.

Sorry. Been too enthralled to comment.

It’s like watching a carcrash in slow motion… No idea what’ll happen next, but I know it’ll be interesting!

Quote:

Sorry. Been too enthralled to comment.

It’s like watching a carcrash in slow motion… No idea what’ll happen next, but I know it’ll be interesting!

Hey Doug, thanks for the reply, I never know if the guys are nodding, shaking or scratching their heads when I post.

May I mention a quick thanks to all the posters who share their varied views and pursuits here on Sways ?

Despite some shameful idiocy, MOST people are very kind and thoughtful.

I f you are ONE of those people, consider this to be your prop for the day !!

As for the “carcrash”,… its coming.

Ive finished the board and tested it already. But I didnt want to start a thread if I didnt have a worthy conclusion.

Thanks to those who watch.

SF.

Hey I got props!

Keep it coming becuase I keep checking this thread :smiley:

Looking forward to the next installment and thanks for posting this interesting one!

This is really interesting, keep the thoughts flowing here…

Thanks to you Doug and Grant.

The plan was to make both sides concave so I built a jig that held the board flat but allowed the sides to open and kept the ends flat. So where the blue is in the pic, I squirted in expanding foam. Maybe at this point you’ll be wanting me to return my Swaylocks key-ring…

I forgot to take pics of the jig.Sorry.

The foam is epoxy compatable, waterproof, sticks like the proverbial and shapes easily.

It filled in from the sides about 2~3 in or so, its not in any way exact but as its not going to be stood on, it’ll do fine.

After it set, I shaped the rails into a concave all the way 'round. It should have very little form drag. ( You know what I mean.)

And then I glassed over the concave rails with carbon and epoxy X 2.

SF.

So how to glass concave rails, I was going to do each side in turn, stick it in a plastic bag and immerse it into the water tank so it would get all-over pressure. Kinda like a vacbag but in reverse and energy efficient. But I didnt.

Instead I put strips of carbon over the rails and then covered it with Saran / Glad wrap / cling film.

Then I laid a rope of compatable diameter into the concave, with added pressure to conform to the curve.

And then gently paper-taped the Saran, the rope and the sides of the carbon down.

Yes , I know, its exactly what you’d see in any pro glass shop.

Bizarrely, when I unwrapped the thing , it was a 9.5… conformed to the concave and smooth.

More pics to follow.

SF.

SF,

two questions:

You’re going to ride that standing? I’m looking forward to some video! Ride report’ll do, though.

This may be obvious, but the most acute curve is the tail, right?

Quote:

SF,

two questions:

You’re going to ride that standing? I’m looking forward to some video! Ride report’ll do, though.

This may be obvious, but the most acute curve is the tail, right?

Hi Janklow,

    Sorry I didnt make it clear at the start but the tail /nose is at both ends, depending on what you want. 

Either side, either end, you can flip the board 4 ways to suit the waves or how you want to surf them.

Ive already ridden The Flipper so Im saving the ride report til the end.

Heres a pic of the concave carbon rails, post cure.

Resin poor, shiny and flat to the intended shape.

Id try some other way next time but I cant fault the result I got with this technique.  

Dumb luck, eh ???

SF.

I love it, especially those concave rails. What’s your reasons behind their design? Your template looks like the template of my new finless board that I have been working on. Thanks for posting, I also attached a pic of one of my old boards that I’ve posted before, it also had concave rails, probably for the same reason that you are seeking? -Carl


This thread is great. Looking forward to the finale, B.

How’s that red and white one work, CO? Do the rails give you hold enough to carve a turn?

Aw Jeesh… NOW I get it. Until I went back and read the text I thought you were making a SUP paddle!

Hi guys,

 Carl ! Good to see youre doing something similar. I like the Red'n'White one!!  

After coming up with all these great new theories and being quite proud of myself, I checked…

None of my ideas are new at all.

I even did the ‘holes thru the board’ back in the 70’s when I was a kid but itd already been done.

The good thing about my ‘new’ design ideas is that theyre new to me, I thought of them myself without knowingly copying anyones prior work. Is it the same for you Carl ?

As for the concave rails, there are several worthy reasons.

With a clean release along the bottom edge of the rails, the board will ride dependant on the outline. The effect of the outline on the performance should be obvious.

With no protruding foam rails, if I hit anything, theres the 2 skins and double carbon / epoxy wraps to take the impact.

Short of hitting a water buffalo, I shouldnt have to worry about minor cracks and dents etc…

With the carbon doubling back between the laps, it appears to give 4 layers of carbon around the rail, ( see blue line).

So like folding paper, it gives it strength by adding extra axises of ‘rigidity’ without adding extra material.

And the sharp rails should be fast.

SF.

Headline reads- " Surfs up."

Wow!

Didn’t see the blowout coming (concave deck/bottom) or the vehicle going up on two wheels (concave rails)!

This is great.

Can’t wait for the ride report… And video would be great.

I suspect it’ll actually fly… Or drown.

One extreme or the other :smiley:

So with the rails done, I scraped a thin layer of epoxy over the deck and hull to make it waterproof and then the board was surf ready.


I’d had an idea that itd be interesting to make a board that flexed but not like these modern wonder boards.

The idea was to provide a bit of suspension and soften out the millions of surface bumps and lumps that a board has to go over and thru.

Hopefully the board would then move with the water in a more fluid manner rather than reacting to every force against it.

Possibly a firm yet yielding surface like a dolphins skin.

So I searched for about 2 or 3 months looking for rubber sheeting, closed cell foam, but it had to be waterproof, have +ve bouyancy and be thin.

And cheap.

Until one shop had a roll of EVA skin, the guy said they skim the top off each block. Its slick on one side and 3mm thick. Ten bucks.

6ft X 3 ft, plenty of room for 2 skins and some left over for the next idea.

I cut the EVA skin slightly larger than the board so after it was glued and dried, I trimmed it back to follow the planshape as closely as possible.

I learnt my lesson with using a skin for bouyancy before, its better to spread it out over the whole area.

And now the Flipper has 6 mm of added bouyancy in addition to the flexible skin I wanted.

SF.

Man this is looking great! Finally some real expirementing and theory put into action! I can’t pretend to quite understand all the forces/tekniques at play here but it sure is looking good!

Christian