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Bomb proof board from XPs insulation foam

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max
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Re: Bomb proof board from XPs insulation foam

Postby max » Sat Jan 21, 2017 11:00 pm

BWD wrote:You can get that rocker I am fairly sure without kerfing, it is helpful to thin the board toward the nose as flexibility relates to the cube of thickness.
Having made a couple of (non-foiling) boards similarly, I think if you use birch ply no glass is needed where you have ply. softwood ply or okoume, maybe some glass.
Also you will probably not need ply on the bottom, glass should do it, or glass plus some veneer or extra thin ply.
Maybe a ply inlay in the area of the box running forward to beyond your front foot position... just throwing experience/ideas out there, best luck!

hi BWD.

This board is purely for foiling. Stiffness is a good thing and also perhaps is keeping the volume in the nose. Basically keeping 30mm thickness throughout its 1200 length. The zeeko aluminium foil setup is not light as such and a bit of volume will help the boards ability to float it easily.

The kerning idea was to try something new to me. The amount of rocker is not extreme so I do have a few options that I am tossing over at the moment.

Like glass the bottom with wrapped rails first and weight it down on the rocker table OR bag 3mm veneer (if you can call it that) to the top with glass in-between and weight on rocker table and then glass the bottom. This would allow me to put some 'posts' in place that would be flush with bottom and through the top veneer before glassing either the top or the bottom.

Will put a pic or 2 up later of the stage it is at.

max
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Re: Bomb proof board from XPs insulation foam

Postby max » Sat Jan 21, 2017 11:36 pm

a few pics

Board with minimal HD insert positions and foil block
board 1.jpg
board 1.jpg (128.33 KiB) Viewed 470 times

minimal shaping on bottom rails . . . bit more to go
board 2 bot.jpg
board 2 bot.jpg (124.17 KiB) Viewed 470 times

3mm skin taped but still needs about 3mm removed from edge to allow placement within outline. WIll be feathered once attached.
board 3 skin.jpg
board 3 skin.jpg (131.03 KiB) Viewed 470 times

TomW
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Re: Bomb proof board from XPs insulation foam

Postby TomW » Mon Jan 23, 2017 8:25 pm

Hi Max,

Looks good. Don't forget to rough up the surface of the foam. The factory extruded surface will delaminate if you don't rough it up.

I recommend making veneer smaller than outline and then shape rails in rounded form to veneer shape. It will look nicer.

Lastly, you can thin the foam towards nose more. It will look less clunky. My surfboards are 5 mm thick foam at nose.

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Re: Bomb proof board from XPs insulation foam

Postby BWD » Tue Jan 24, 2017 12:30 am

:thumb:

DartBoard
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Re: Bomb proof board from XPs insulation foam

Postby DartBoard » Tue Jan 24, 2017 7:10 am

:jump: Looking good!

max
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Re: Bomb proof board from XPs insulation foam

Postby max » Tue Jan 24, 2017 12:04 pm

TomW wrote:Hi Max,

Looks good. Don't forget to rough up the surface of the foam. The factory extruded surface will delaminate if you don't rough it up.

I recommend making veneer smaller than outline and then shape rails in rounded form to veneer shape. It will look nicer.

Lastly, you can thin the foam towards nose more. It will look less clunky. My surfboards are 5 mm thick foam at nose.

Thanks again Tom.

As for thickness at the nose . . . plan on keeping most of the volume to help float the Zeeko Alloy foil and for touchdowns.

Agree, it would look better thinned and if it was not purely a foil board (smallish at 118 for my ability), it would be getting thinned out. Maybe a good excuse to build another once this one is finished and tested. :)

max
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Re: Bomb proof board from XPs insulation foam

Postby max » Tue Jan 24, 2017 12:06 pm

DartBoard wrote::jump: Looking good!

Cheers Matt.

WIll try to get a bit further with it this weekend and post some more. Not sure I fully trust this foam yet but will certainly be a cheap enough build . . . materials wise.

BWD
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Re: Bomb proof board from XPs insulation foam

Postby BWD » Tue Jan 24, 2017 2:29 pm

If you sanded the foam to 60 grit or coarser and coated with a good resin layer you should have no worries with adhesion.
It will be stiff as hell no worries there. I built one of 3mm ply / 25mm xps foam / 3mm ply glued with epoxy, and stood in it with supports at nose and tail. It flexed about <15mm with 80kg in the middle.
Great except when chop is too steep or square... but hard on the knees.

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Re: Bomb proof board from XPs insulation foam

Postby DartBoard » Fri Jan 27, 2017 6:12 am

Hey Max,

I see you decided to put the ply skin top and bottom instead of just glass. What made you reconsider it?

Cheers

max
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Re: Bomb proof board from XPs insulation foam

Postby max » Fri Jan 27, 2017 12:01 pm

DartBoard wrote:Hey Max,

I see you decided to put the ply skin top and bottom instead of just glass. What made you reconsider it?

Cheers
Hey Matt . . . no, just a 3mm skin on the top (6 onz under and 2x 6onz on top wrapping rails) and will go with just glass on bottom.

Bottom 3x 6onz plus a 200mm wide 6onz carbon strip for about 800mm from the tail. Wrapped rails also from bottom.


Well, that is the current plan. Hope to bond the wood top on this weekend and then put in the strap inserts and inserts for the foil mast, and then shape the rails into the top.


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