Shinai is born - Shinai je rođen

On left is Shinai, my new kite board!  On right my 2011 build (no name:)

By suggestion from kiting community, and being a bamboo board, hence Shinai ((竹刀) - is a weapon used for practice and competition representing a Japanese sword.

Weight before accessories 2545 grams, 137x40.5cm, concave 3mm, rocker about 3cm (straight 1/3).

And now for my next project, I'll make some fins for my board...

Kite board rails and varnish - Rub daske za kajtanje i lak

As I've left some bamboo ply all around kite board rails, now is a time to cut it and make rails. Huh, that was a tough job!
Since my board was glassed on both sides, it's very hard to cut fiberglass, even harder with a hand saw! Decided to finally buy a jig saw, but even with that was not easy to cut.
The problem is, glass is an insulator and the metal blades tend to overheat quickly and than metal just melts. Spent a few good blades for this...
Anyway, finally the board is cut. Now I need to sand out bamboo excess and finally got myself another machine to work with, a belt sander. Made this setup which worked perfectly:

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Kako sam ostavio nesto bambusa oko rubova daske, sada je vrijeme da dasku ispilim na mjeru i napravim rubove. No to nije bio lak posao!
Kako je f. staklo na obje strane, vrlo ga je tesko rezati, jos i teze sa rucnom pilom!
Konacno se odlucih kupiti ubodnu pilu, no ni s time nije bilo nista lakse.
Problem je sto je f. staklo izolator i metalni noz ubodne pile se brzo ugrije i nakon toga rastopi.
Potrosio sam cak nekoliko dobrih nozeva za ovo...
Konacno, daska je izrezana. Sada trebam pobrusiti rubove od viska bambusa i za to sam si kupio novu masinu, brusilica sa remenom. Napravih ovo i radi izvrsno:

One hour or so and was finished. Must remember to have a decent breathing mask, this is a fiberglass I'm sanding and it will be a nasty thing to breath!

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Nakon jednog sata bilo je gotovo. Zapamtimo koristiti dobru masku za disanje, jer brusiti fiberglass i udisati ga je nezgodna stvar!

Finally, it's coming to an end!
Now I just need to varnish the board and how long it takes to make a board, it might take even longer to varnish it!
However, this time I'll be doing both sides in one single run. And the above photo is showing how. I've placed 4 small clamps and will rest my board on it while varnishing the other side.
And, important thing, there is enough space to place a 100W light bulb under the board to generate some heat.
Than, I've placed a styrofoam on sides and top, covered with towels and left over night... Process repeated 5 times. That is 5! Would like a super shine board!

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Napokon, doslo je do kraja!
Vrijeme za lakiranje je skoro isto koliko treba da se napravi daska!
No ovaj puta lakirati cu obje strane od jednom. Na gornjoj slici se vidi kako. Stavih 4 male stege na koje cu okrenuti dasku i lakirati drugu stranu.
Zatim, staviti cu jednu zarulju od 100W ispod daske tako da ju grije. Mjesta ima dovoljno.
Nakon toga, sa malo stiropora daska ce biti kao u kutiji da se lak brze osusi preko noci...I citav proces ponoviti cu 5 puta, dakle 5 farbanja!

"Mega" kite board rocker - "Mega" od zakrivljenosti kite daske

After I got my kite board of the vac table, was quite surprised to find just a tiny board rocker. The bamboo spring back is much more than 30%, and wasn't expected this.

So what to do now? I could glue a second bamboo layer on top of it to get a decent rocker. But, it won't be a light weight board any more.

So, made an experiment and used a carbon - kevlar fiber fabric on top of bamboo strip to see how that will work.
And, I got some rocker.

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Nakon sto sam skinuo dasku sa vakumskog stola, iznenadilo me da je zakrivljenost (rocker) daske skoro nestala. Naime, kod bambusa je ocito povrat elasticnosti znatno vise od 30%, sto nisam ocekivao.

Dakle, sto sada napraviti? Mogao bih zalijepiti jos jedan sloj bambusa da dobijem pristojnu zakrivljenost. No tada daska nece vise biti lagana, vec znatno teza.

Onda sam za probu zalijepio carbon kevlar fiber platno na gornju stranu bambusa da vidim kako to radi.
I, dobih zakrivljenost.

 
To cut a kevlar fiber fabric is a real pain. You'll ruin a decent scissors in a second and fiber will be everywhere. And because I like to complicate things I want my carbon kevlar fiber on top on my board but not from rail to rail.
Than, I was thinking why not to semi cure some epoxy and than cut it? Immediately after, vacuum bag it.

Worked as a charm!

1) First I need a template for applying epoxy on carbon kevlar fabric.
2) Than applying just enough epoxy around a template.
3) One hour after I cut kevlar  with an extremely sharp knife around a template.
4) Done. Carbon kevlar fabric is now ready for my "mega" rocker vacuum jig - 10 cm! Used 50g 5:1 epoxy.

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Rezati carbon kevlar fiber platno nije lako. Cak i pristojne skare ce biti neupotrebljive nakon par sekundi rezanja i tkanina ce se razici po svuda. I naravno, zato sto ja volim komplicirati stvari, zelim da moje platno bude na gornjoj povrsini daske ali ne od ruba do ruba.
Onda sam dosao na ideju zasto ne bih upotrijebio epoksi i nakon nekog vremena probao rezati platno? I odmah nakon toga na vakum stol.

Radi odlicno!

1) Prvo mi treba sablona da nanesem epoksi na carbon kevlar platno.
2) Nakon toga nanesem malo epoxija oko sablone.
3) Nakoj jednog sata sa vrlo ostrim nozem izrezem platno oko sablone.
4) Gotovo. Carbon platno je sada spremno za moj vakumski stol i "mega" zakrivljenost- 10cm! Koristio 50 grama 5:1 epoksi.


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And 10cm jig for the rocker is because I'm still expecting 50% and more spring back! And that might make just about a decent rocker of 4cm:) Will see tomorrow! Can't wait...

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Zakrivljenost od 10cm je radi toga sto ocekujem 50% povrat uslijed elasticnosti! Sto ce mozda ostvariti pristojnih 4cm rockera! Vidjeti cu sutra, jedva cekam...

Under the pump - Pod pritiskom

As promised (to myself:), today I laminated my bamboo kite board with a few layers of fiberglass. Used bi-ax 200g glass with 45 degrees layer in the middle overlapping the foot pads, two layers under the foot pads and one orthogonally layer for the whole board length. Used 180g (3:1 by volume or 3.5 by weight ), epoxy with the 403 West S. filler.
I was expecting to use much less epoxy however using a filler makes it more complicated to wet out. Will see when I'll glass the bottom with no filler how much epoxy will use.

Decided to use my new vacuum table which is efficient way to get the rocker. The concave is here as well, made with two 1mm balsa veneers and placed underneath. I think it was possible to place 20-30 cm wide fiberglass under at the same time to keep that concave in place. Maybe I will do that next time.

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Kako obecah samome sebi, danas sam lijepio moju bambus dasku sa nekoliko slojeva fiberglasa. Koristio sam dvo-osni 200g fiberglas pod 45 stupnjeva u sredini preklapajuci mjesto za vezove, zatim dva sloja na mjestu za vezove i kompletan sloj po duzini. Utrosio 180g (3:1 epoksi volumno ili 3.5 po tezini), epoksija sa 403 West S. mikro granulama. Mislio sam da cu trebati znatno manje epoksija no koristeci mikro granule dosta je tesko navlaziti tkaninu. Vidjeti cu koliko ce trebati za dno daske bez tih granula.

Odlucih se za novi vakumski stol i efikasnu zakrivljenost. Konkava ispod daske je takodjer tu, na nacin da stavih dva slojeva balsa furnira od 1mm ispod daske. Mislim da sam mogao istovremeno staviti 20-30cm siroki fiberglas ispod daske tako da se zakrivljenost konkave zadrzi, mozda drugi puta i uradim tako.

It will take a few days to cure this super clear epoxy....

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Trebati ce nekoliko dana da se ovaj specijalni super proziran epoksi osusi...

Getting there to my new kite board - jos malo do nove daske

Thanks to Matt and his idea for a new board!

 All the details and the design are in the Board Design page on the right hand side at the bottom of the page, B8 - WakeUP:

http://www.boardbuilders.co/p/board-project-plans.html

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Hvala Matt na prijedlogu za novu dasku!

Detalje daske mozete pronaci na desnoj strani u dnu pod B8 - WakeUp:

http://www.boardbuilders.co/p/board-project-plans.html

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My gut feeling is that this will be quite beautiful board:)

Hope you'll share my view!

First things first.

This time I was using the router with the attachment I've got with it. This attachment enables me to do an offset by moving bottom part by 1-2cm.

That way I can make a smaller or a bigger board with one single template! However, the catch is the template should be below the routed surface, not on top. This is not really easy to do, at least for the first time.

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Duboko sam uvjeren da ce ovo biti prekrasna daska:)

Nadam se da cete dijeliti moje misljenje!

No, prvo najvaznije.

Ovaj sam puta koristio router uredjaj sa dodatkom koji je dosao sa uredjajem. Taj dodatak omogucava mi da pomicem router za 1-2 cm prem unutra ili van.

Tako da mogu napraviti manju ili vecu dasku samo sa jednom šablonom! No, postoji problem sa time i to je da šablona mora biti ispod povrsine koju radite, a ne iznad. To nije jednostavno, bar za prvi put.

The template is below my new board!
Tapered rails! Done with a belt sander in 10 minutes! After that drilled fin and footpad holes. Than poured epoxy into the rails. Used 60ml per side, 120ml all together. Epoxy 5:1, with red and orange pigment. Pigment ~5%.

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šablona je ispod nove daske koju radim.
Obratite paznju za kosinu zlijeba! To je vodena strana! Kosina izradjena sa rotacionom smirgl masinom u 10 minuta. Nakon toga izbusene rupe za perajice i vezove za dasku. Sledeci korak epoksi ljepilo u zlijeb. Utrosio 60 ml epoksija za svaku stranu, sve skupa 120ml, epoksi 1:5 sa crvenim i narandjastim pigmentom. Pigment oko 5% tj, dva puta na vrh skalpela:) Od okativna metoda.

Remember my pre-made fin inserts? With 5 min epoxy and pre-made inserts all done in a jiffy...

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Ovde dolazimo do unaprijed izradjenih drzaca za perajuce, ako se sjecate? Jednostavno sa 5 minutnim epoxijem i drzacima, sve napravljeno u tren oka...

Now it comes to the vacuum table! Still thinking if I'll do my standard vacuum method or will go with this:

Sada dolazi odluka oko vakumskog stola. Jos razmisljam da li da koristim moj standardni vakum stol ili ovo:

The above method is easy but no concave. Will run some tests and see...

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Gornja metoda je jednostavna za dobiti zakrivljenost daske, no ne i konkavnost. Uraditi cu par proba pa odluciti...

Inserts test run - probni drzaci peraja

Fins inserts:

This is a second run. The middle insert was made first, didn't like the shape. This one is more what I'm after. But didn't like the color! It looks the same but it's not. Only middle one is a fluorescent orange, flash probably made it to look the same, see:

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Ovo je drugi probni uzorak. Uzorak na sredini je prva proba, no nije dobar oblik. Ostali uzorci su noviji i oblik je u redu. No ne i boja. Izgleda isto no nije. Trebala bi biti flurescentna boja kao sto je srednji uzorak. To se vidi najbolje ba doljnjoj slici:

Now a third run...

Let the kite boards begin - izrada novih kite board dasaka

I just sourced Paulownia 1500x600x15mm, Bamboo 3 pieces by 1800x420x5mm and Marine plywood 2 sheets by 1560x480x3mm.

Yeah, let the board games begin!!!

My plan is to build lightest board as possible and with initial calcs Marine ply is the lightest but Bamboo is not to far by 200 grams only.
Yeah, let the board games begin!!!

My plan is to build the lightest board as possible and with initial calcs Marine ply is the lightest but Bamboo is not to far by 200 grams only.

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Upravo nabavih nekoliko dasaka: Paulownia 1500x600x15mm, Bambus 3 komada 1800x420x5mm and Marine sperploca 2 komada 1560x480x3mm.

Dakle natjecanje za najlaksu dasku upravo pocinje!!!

Plan mi je sto laksu i cvrscu dasku te sa probnim racunom Marine sperploca je najlaksa, no bambus je tezi samo 200 grama. Paulownija drvo bi svakako bilo vrlo vrlo lagano da je recimo 5mm debljine. No nije, vec 15 mm i previse je posla da bih je napravio tanjom.

 To be continued...