I wanted to show off my latest home crafted board now that I've had a chance to get it out on the water and put it through it paces. Its a 137x41 cm wake style board with a paulownia wood and PVC foam core and ABS rails.
The thing that really novel about it is that I used 300gm Basalt Fibre in the layup as an alternative to carbon and glass. As far as I've seen so far this is the first time Basalt Fibre has ever been used in a kiteboard - there you go a world first and you heard it first on Seabreeze
Basalt Fibre is quite impressive stuff. Its got around 70-80% of most of the physical properties of carbon with one major exception in that it stretches around 3 times further before it breaks so none of the brittle failure you see with carbon. Its also about 40% cheaper than carbon.
It is literally molten basalt rock. The basalt is dug up from old volcanic pits, crushed, melted and drawn into a thread.
It get some use in composites but as I understand one of its big uses is in fire resistant clothing like firefighter suits. Until recently when www.playwithcarbon.com.au started to sell it you could only get it in industrial quantities. These guys sell it by the meter.
Without resin its got this amazing metallic sheen to it because of the high metal content of it ( its once was magma in the earth!).
Unfortunately, when you wet it out it looses that luster and it more an amber color which has a different but not as great impact as the black of carbon.
The board has got loads of rocker in it. 50mm. I was aiming for 40mm but it didn't spring back like I though it would. This has turned out to be a great asset as it pops off chop and makes for a edge that is really easy to engage or fully disengage with relatively little effort. It carves like an absolute champion and the extra stiffness in the board makes it lively on the water compared to my other attempts that are very thin and so they flex all over the shop for a smooth ride but a mushy feel during any tricks. The big amount of rocker does reduce the the upwind performance but overall I think this is the best outcome so far.
On the next board I want to have a crack at putting some channels in the tips. The tips are a bit slippery (fins a long way towards the center in order to get then as far from the heal as possible) so when you come off the lip of the wave the tail can spin out unless you are edging hard. I'm hoping channels will give that extra bit of grip to see it to the end.
As always, the whole guts and glory of the build is on boardbuilders.co
[URL]boardbuilders-forum.1077691.n5.nabble.com/Franken-Board-td963.html[/URL]
I don't know much about making boards (other than it looks like a lot of work) but that looks great! And using mag-muh is cool
sweet. I've seen longboards built with bassalt but never a kiteboard. So good effort for blazing a trail.
is it only one layer of basalt top and bottom?
Nice work, you just need to setup a stunt with a ring horseshoe of fire and test out its fire rated properties.
Nice build! Good to see you going custom custom! Really, this forum has produced some fantastic self builds. I really like that you have tried something new here, I would have never considered basalt fiber. Do you know what it weighs in comparison to carbon? I actually like the wet look and wonder how it would work on a surfboard. If it stretches more than carbon it could offer the strength and the feel of a good poly board.
this forum has nothing to do with these board builds they are all on boardbuilders - forum dart board . it just a great blog for new and old kiteboard builders to show of their builds
Thanks everyone.
Without accessories the deck came in a 2.2kg which is about 200gm more than the other boards I've made using the 195gm e-glass in place of the 300 gm basalt.
Plummet, yes, in this board I've only used the basalt as the top and bottom layer and there is 450gm stitched e-glass under. I've got a plan to try a basalt only board. This was a bit of an experiment to see what it was like to work with basalt. Data on all this stuff always give fairly wide ranges for properties so I was keen just to do something with it and see how it turned out and then go back and tweak and test variations on it.
The density of basalt is quite close to e-glass (2.6gm/cm3) compared to carbon fibre which is much lighter at around 1.8 gm/cm3.
A few sources put the properties of it something like s-glass only a bit stronger and stiffer and I have only ever been able to find s-glass in very light weights.
Dafish, found some more numbers that might be of interest:
Tensile strength
Carbon fibre (medium) = 5.1 GPa Basalt = 4.14-4.8 GPa e-glass = 3.4 Gpa
Elastic Modulus ( stiffness, all else being equal)
Carbon fibre ( med) = 250 Gpa vs basalt fibre = c.110 GPa vs e-glass 70-80GPa
Elogation before breaking (% it will stretch before breaking)
CF = 1.4%, basalt = 3.2 % e-glass = 4%
The big attraction is its much cheaper than carbon and isn't brittle like carbon.
Dafish, thanks for the tip on long boards, I'll check them out and see if any of those builders can give some ideas about the pro's and cons.
Cheers
matt
Select to expand quoteKAOS69 said..
this forum has nothing to do with these board builds they are all on boardbuilders - forum dart board . it just a great blog for new and old kiteboard builders to show of their builds
Thanks Kaos69 - looking forward to seeing your handy work up there now that you've got re-excited about making some more mean machines!
In case anyone is interested in experimenting with a similar style of board, the 1:1 scaled plans in pdf format can be downloaded from the Project Plan tab at
[URL]www.boardbuilders.co/p/board-project-plans.html[/URL]
It includes the outlines for both decks and the rocker jigs for a rocker table ( side and center jigs). The plans are all taken from the design in the design spreadsheet 'BoardOff' you can also download from the site.
Also, to give you some idea of how much stiffer this board is, when I design the boards I've been using the flex model in BoardOff with a benchmark test of 20kg load at the tip and the model spits out the side profile of the board from the middle and from under the footpad to the tips. In the soft boards that I've been making before now the design goal was to have the board bend up 10cm at the tip when it was clamped at the middle. This is 'wobble board' teritory. For the basalt board the core is nearly twice as thick and the basalt stiffer than the FG it replaced so under the same test the tips bends up about 30-35mm
In the chart above, the blue and pink lines are what the board looks like from the side when you clamp it in the middle or under the heal and bend the tip up under the test load of 20kg at the tip. The black line is the curvature (helps to see the flex another way that is easier to compare with other designs). There is a kink in it because the of the upper deck ending abruptly.
