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Thin build, flexible with strength.
Posted: Mon Feb 17, 2014 10:43 pm
by SURFFOILS
No I'm not talking about your wife, but how thin could you build a paipo and still maintain structural strength ?
I'm thinking of layering glass and veneer several times but what else would work ?
Re: Thin build, flexible with strength.
Posted: Tue Feb 18, 2014 12:38 am
by spudnut
Personally, the idea of a thinner wife excites me more. I am not sure that if the rails are kept thin, that having a thicker body might be more advantageous ( rolled bottom effect ) than just super thin and flat; which bring me right back to the wife effect!

Re: Thin build, flexible with strength.
Posted: Tue Feb 18, 2014 3:09 am
by SURFFOILS
Ive tried the thick and the thin and the curves are better.
But back to the paipos....
I'm thinking the veneer adds more strength than the glass layers but the resin and glass will hold the layers of veneer apart to build up thickness and multiply the rigidity of the wood.
I can't think of anything else that would be formable like the veneer as I'm not doing a flat paipo.
The plan is to make a male EPS mold and vacbag layers over it.
Re: Thin build, flexible with strength.
Posted: Tue Feb 18, 2014 8:22 am
by bgreen

- P1030251 (450 x 600).jpg (71.63 KiB) Viewed 12216 times
Brett,
http://www.paipo.com/ &
http://ocean.victoriaskimboards.com/foamie/ (Thanks Nels). These are both well under 1" thick.
Durability - see
http://www.youtube.com/watch?v=1dptdD95YPo
Flat can be good - see attached on the right.
Bob
Re: Thin build, flexible with strength.
Posted: Tue Feb 18, 2014 10:31 am
by GeoffreyLevens
Don't know where to access photos but many years ago, Dale Solomonson built a guitar pick style paipo of only carbon fiber glass and epoxy. He then added closed cell foam pad to deck for removable extra floatation. You can shape in full rails (Greenough Velos style) w/ super thin body of any shape and pretty much totally separate "shape" from "float". You knew that of course. Dale was aiming for highest amount of very snappy stiff flex he could get and the board did snap in a large, powerful wave, nearly cutting him in half, but that was more a materials use error/experiment than a shape issue I think
Re: Thin build, flexible with strength.
Posted: Tue Feb 18, 2014 3:29 pm
by bgreen
I believe this is the board Geoffrey is referring to. If not. sounds similar.
Bob
Re: Thin build, flexible with strength.
Posted: Tue Feb 18, 2014 10:53 pm
by SURFFOILS
Wow! That board there ^^^ is great and that's the kind of thing I'm thinking of but with downturned wingtips.
Possibly build an EPS foam mold and vacbag layers of glass and veneer over it.
And here's another paipo-ish craft under construction with a foam nose cone and an inflatable hull.
Re: Thin build, flexible with strength.
Posted: Wed Feb 19, 2014 2:13 am
by Poobah
I've had thoughts in the past about doing somethng similar, except I was going to form it on an old windsurfer (the front half of the deck) instead of building a plug.
Were you planning on 1/8 inch bending poplar for the veneer?
Annother kooky idea I've never tried....give the fiberglass a sort of egg crate structure by glassing on top of a bunch of wooden dots, like the little wooden things that are made to cover screw heads on furniture.
Re: Thin build, flexible with strength.
Posted: Wed Feb 19, 2014 3:33 am
by SURFFOILS
A windsurfer would be a great plug to work on, I wish I'd thought of that at the start !
The wing tips will be down turned and I'll do a small amount of lift in the nose. Hopefully it will be a stylish piece of wood and glass with planing area for low speed lift and enough down turned wingtip area for high speed control.
If it was going to be flat I would've gone with XPS and epoxy but with the curves I think veneer is the best way to go.
I've got tonnes of 1/16 veneer of native Australia wood so I could put single or double sheets between layers of glass.
There's a lot more thought to come before I start.
Re: Thin build, flexible with strength.
Posted: Wed Feb 19, 2014 4:49 am
by All about water
Sure this will be an impressive board! At least I am

Re: Thin build, flexible with strength.
Posted: Wed Feb 19, 2014 12:48 pm
by GeoffreyLevens
Thank you Bob! That is the very board. And of course after riding it (and snapping it) Dale had many changes in mind if he ever did a next iteration.
Re: Thin build, flexible with strength.
Posted: Wed Feb 19, 2014 4:30 pm
by airboy808
How did the Dale S. board work? Did you see it in action GJ?
Looks super fun and can't wait to see what SF is cooking up
Re: Thin build, flexible with strength.
Posted: Wed Feb 19, 2014 9:45 pm
by SURFFOILS
Here's the basic planshape, it looks too wide in the tail but remember the sides are rolled down so it won't be as wide as it looks.
Here's the right half of the shape. I'm keeping the middle 14 " of the deck flat (red dots) and then rolling the sides down.
Ive scalloped the back corner to shorten the length of the side tips. (Green dot)
And the overall curve from the front view.
The lowest part of the tips are 4" below the deck because I wanted to create deep hold similar to a finned board.
Re: Thin build, flexible with strength.
Posted: Wed Feb 19, 2014 10:12 pm
by SURFFOILS
The problem with the curve is that as you curve a hull down into a concave it loses its planing area but the concave is essential to get the depth for the fins. Odd curves underwater can be unpredictable too so I might need to reduce the area where it's curved.
Here's the area where the curve is neither horizontal or vertical. between the red dots.
So one solution is to use cut-outs on the sides to reduce the area where the curves aren't an advantage.
So now there's a middle planing area and a minimalist 'outrigger' configuration leading out to the downturned tips that create a deep set side fin on each side.
Call me mad but it will be a unique ride.
Re: Thin build, flexible with strength.
Posted: Thu Feb 20, 2014 10:13 am
by GeoffreyLevens
airboy808 wrote:How did the Dale S. board work? Did you see it in action GJ?
You meant GL yes? Never saw it, only remembering telling me about its catastrophic failure which I think led to trip to the ER
Re: Thin build, flexible with strength.
Posted: Sat Feb 22, 2014 4:36 am
by SURFFOILS
Glued the EPS blocks together for the mold.
Re: Thin build, flexible with strength.
Posted: Sat Feb 22, 2014 4:00 pm
by bgreen
Ok, keep them coming.
Bob
Re: Thin build, flexible with strength.
Posted: Sun Feb 23, 2014 4:01 am
by SURFFOILS
Changed the outline and working out how to carve the eps to get the correct shape.

- image.jpg (112.34 KiB) Viewed 8606 times
I'll start shaping the mold tomorrow.
Re: Thin build, flexible with strength.
Posted: Sun Feb 23, 2014 9:25 pm
by SURFFOILS
Nose rocker done, one side done.
And a selection of woods to use for the veneer, there's some supple woods like pine and Victorian Ash and some brittle one like Jarrah and a Spotted Gum. The Jarrah seems stronger but it's not a smooth wood that will create a smooth surface on the final product so I'm going to use the pine and ash.
Re: Thin build, flexible with strength.
Posted: Sun Feb 23, 2014 11:55 pm
by SURFFOILS
Spackled and ready to sand.
Then a coat or two of resin before I start planning the veneer pattern.