Openly leaning my face into the strike zone with this thread.....don't hold back the fastball,
I don't care what's thrown, this ones going out of the park!.
rails look too boxy. Super white foam, hard to discern the the outline. blends in too much to the background, Shaping room lights too high and too bright also.
Really poor camera skills, too. Contrast is WAAAY to low.
A colour shot might be better?
Ha Ha sorry pics will be coming
First I must define the design intent:
Light, strong, AND cheap, the cheap part is why I'm building it.
It won't be cheap by swaylocks standards but cheap by off the shelf standards.
I read a bunch of Ben Thompsons old posts on here, about surfboard stiffness. although he didn't finish his experiment completely, one of the most interesting conclusions he made was when given a bunch of identically shaped surfboards with various stiffness. in blind tests, surfer unanimously preferred the lighter boards. So I'm going for weight.
I break shit, all the time, I'm not particularly careful, but also have a view that things should stand up to real life. that means ghost surfing into the rocks hitting the odd driftwood, scraping the fins on the bottom, stomping airs, dropping the board, blowing away on the beach (I said light) and just plain not snapping in half.
Simple dings if used undetected are board enders most EPS boards due to water absorbtion into the foam. I've done this repair too many times to be satisfied with current eps construction.
So strong and impenetrable is what I'm after.
I had screwed around with this earlier in the following thread.http://www.swaylocks.com/forums/new-guy-new-test-lab
lightweight spectra cloth over 1/8" corecell over 4.5oz uni directional carbon fiber on 0.75lb EPS.
lighter and stronger but the real benefit is a hugely durable surfboard.
Spectra is the lightest strongest fabric in the world, is incredibly abrasion resistant and the panels can be beaten with a hammer with zero penetration
It will do a better job of keeping cracks/dings and leaks from getting to the eps core than any other material.
The carbon fiber is "armoured" by the spectra and the corecell.
Being considerably stiffer, the carbon fiber will be carrying most of the structural loads. burying it beneath the corecell balances this out a little but ultimately the armoured carbon will be the load bearing member and very well protected.
The spectra doesn't bond terribly well to epoxy so a load bearing unidirection carbon skin is ideal material to take the buckling loads.
This material combination is lighter than a 4 + 6 glass.
Although the Extra bondng of corecell adds resin weight, it's likely I can get this board as light as a typical pro board by using a light weight core especially when water penetration will not be a concern.
strong light impenetrable
I'm wondering how the deck holds up to denting. Corcel alone of .75 EPS will dent like crazy. With Carbon? How hard is it to shape? It might be realy soft and spongy.
... But polyethylène on the outside is very hard to laminate. It's also expensive in woven form.
What is the density (pcf) and minimum compressive strength (psi) of the 1/8" corecell you are using as the outer skin?
Years ago dpiction posted a method using a corecell skin over what I think was an O-C Foamular 150 XPS housing insulation (1.3 pcf, 15 psi) core.http://www.swaylocks.com/comment/384532#comment-384532
Swaylocks Surfboard Design Forum: thoughts & theories ... practical & theoretical
RAIL PROFILE http://bgboard.blogspot.com/2014/03/march-82014-afterr-seeing-recent.html
All very very good warnings
Every surfer: I've use .75lb and 1lb foam. In kiteboards. (see below)
I'll take pics of my blanks, shaping isn't pretty but isn't hard.
bagging requires vacuum control to prevent crushing it.
rails and finboxes need re-inforcments.
Was planning on running 90 degree 6 oz carbon. Under the impact zones. In addition to the 4oz 0 degree. That will give me the same amount of fabric for dent resistance While being stiffer than glass
I'm not worried about dents, carbon is really stiff and doesn't really bend much , it just breaks.
Went with uni. As at 90 it won't create a lot of additional stiffness. And will reinforce the 0deg. Carbon in impact
This board is gunna be pretty stiff I don't wanna make it worse. but weight trumps flex according to Ben t's. Blind experiments
Stone burner using 80kg/m3. divinycell 200psi compressive strength (5lbi/ft3 (ish)
Have multiple boards with years of beat downs as strapless kiteboards with the following
1/8 80kg/m3 corecell
6oz e glass
1/8" corecell 80kg/m3
I believe that's a typical Bert Berger style construction.
1.5lb eps is readily available but adds a lot of weight.
Jago. I like the hard way. This will surely require multiple trips to the vacuum bag
Regarding cost, since it doesn't bond worth a crap, can't be cut and is generally shit to work with no one wants the spectra. generally what good is a really strong fabric that doesn't bond well so can't be used structurally. good in ballistics only
Find a composite store that brought in a big roll and they are usually eager for you to find a use for the stuff to take it off their hands.
I'm getting it cheaper than most other expensive stuff.
Not gunna give up my source yet i. may wish to put a lowball offer on the roll depending how this goes.
Are you doing corecel on top and bottom? I did a corecel carbon on deck and bottom once. It was way too stiff. No flex at all. I then started only putting corecel on the deck.