Fins inserts - kite board peraje

Made a perspex mold for epoxy fins inserts. Filled with epoxy with some orange powder pigment.
Notice that orange inserts are smaller than a hole. This is after I drilled 3mm more into the perspex to achieve "step down" - basically a straight hole and than counter sink with 45degrees.
I think this will make better contact with the board since wood will be drilled on the same principle.

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Kako bih ugradio kite board peraje odlucio sam napraviti kalup za drzace peraja. Kalup izradjujem u pleksiglasu koji cu ispuniti epoksijem sa narandjastim pigmentom. Primjetite da su obojeni drzaci manji nego sto je rupa u pleksiglasu. To je nakon sto sam odlucio produbiti pleksi za 3mm tako da dobijem "prijelaz" - sa "obicne" rupe na konus pod kutem od 45 stupnjeva. Tesko je objasniti. No mislim da cu tako dobiti bolji kontakt sa drvetom posto ce i daska biti izbusena po istom principu. Nakon toga samo ubacim "drzace" za perajice uz malo ljepila i gotovo!

The perspex is drilled with counter sink on quite slow speed with this attachment for better positioning:

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Pleksiglas je busen sa "konusnim" svrdlom sa malom brzinim okretanja busilice i drzacem za precizno busenje:

It must be on a slow speed since will burn perspex easily on a higher speed. No way to use plunge router for this. At least not without speed control. So my idea of precured rails will not work:(

One thing, powder pigment and epoxy will not give good results when applying on board! I do not know why is that since I've mixed it for 5 or more minutes but pigment wasn't really dissolved leaving many visible marks on my test run. Will stick with other pigments, not powder based.

The idea of precured fins inserts is just to speed up the things!


P.S.
Precision tool. Wouldn't do it without one! 

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Busilica mora biti na sporijem okretanju inace se pleksiglas moze rastopiti. Ideja mi je bila koristiti router, no prebrzo se okrece model koji ja imam.

Jedna stvar, pigment u prahu i epoksi ne daje dobar rezultat kada je upotrebljen na dasci. Naime, pigment se nije dobro rastopio iako sam mjesao vise od 5 min epoksi. Nakon primjene, vidljive su grudice pigmenta na probnom uzorku. Dakle, bolje je koristiti tekuci pigment.

Ideja izrade drzaca perajica u kalupu je samo da se stvari ubrzaju!

P.S.

Bez preciznog drzaca ne bih radio ovo!

Vacuum quick release - vakumski ventil

What to say after a while? :) Well, for a start, the kite surfing season just finished for me. Managed to learn some new tricks, not much though. It was an unusual season with only 20 or so sessions on the water:( Also managed to break my hand made board. Sort of. It didn't really break. It's just a tiny crack from a side to side under my foot and needs fixing. This happened after a Jump. And this Jump was not for heart fainted. At a middle of it, I was thinking that will flew over the trees. Not at, or trough, but over 15-20m tall trees:( In a split second decided to land before the trees, to avoid becoming a something like Christmas tree decoration:) Landed dead flat and the board snapped. Of course, it snapped because the bottom of the board was not fiber glassed. Didn't have a time to do so, holidays coming etc. Now we will concentrate how to, hopefully, fix it! But first, I need a better vacuum connector, or a quick release. Coz, I'll glue some Bamboo veneer to my board in a vacuum bag.

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 Sto da se kaze nakon toliko vremena? :) Za pocetak, kite surfing sezona je zavrsila za mene. Protekle sezone naucio sam par trikova, nista posebno. Sezona je bila losa, uspio sam biti svega 20-tak puta na vodi:( No, uspio sam slomiti moju dasku. Ne skroz. Nije slomljena do kraja. Nekako je samo lagano napukla sa jedne strane na drugu tocno ispod vezova i potrebno ju je popraviti. Desilo se to nakon sto sam skocio. No, to je bio skok za pamcenje. Usred skoka, mislio sam da cu jednostavno preletjeti obliznja stabla. Ne zabiti se u njih ili sletjeti na iste, nego preletjeti preko 15-20m visokih stabala. U djelicu sekunde odlucio sam sletjeti prije nego postadoh Bozicna dekoracija:) Sletih sa totalno rvnom daskom i u tom je trenu napukla. Naravno, napukla je jer nisam stavio fiberglass na doljnju povrsinu daske. Nije jednostavno bilo vremena, problizavali se praznici i to je to. Sada cu se koncentrirati na popravak, nadam se uspjesno! No prvo, potreban mi je bolji vakumski ventil za vakumsku vrecu. Jer cemo lijepiti bambus furnir na dasku u vakumskoj vreci.

The above are the parts from my "enhanced" vacuum connector. The main part is Check valve! Last but not the least some Perspex with a hole to connect Check valve and some channels at the bottom for air evacuation. How does it work? I always try things before "production" usage:)

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 Na gornjoj slici su svi porebni dijelovi za moj "redizajniran" vakumski ventil ili konektor. Najvazniji dio je "jednosmjeran" ventil, ne znam Hrvatski naziv, sorry. Drugi isto tako vazan dio je komad plexiglasa sa rupom za ventil i par kanala na dnu plastike za evakuiranje zraka. I kako to sve radi? Uvijek probam stvari prije "pravog" koristenja:)

The above photo says everything! After 2 hr, vacuum was still holding. The slightly raised  area around stainless steel nut is Blue Tak to keep everything air tight!
All of the above for this:

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Gornja slika sve govori! Dva sata nakon sto je vrecica vakumirana, vakum jos drzi. Malo uzdignuta povrsina oko matice od nehrdj. zeljeza je "plastelin" tj. ljepljiva masa koja drzi sve "zabrtvljeno"!
A sve to da bih dobio ovo:

On the side left with a piece of lace is the vacuum connector, vacuum holding for 10 hours! Stay tuned...

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Na slici lijevo je vakumski konektor spojen sa spagom, vakum drzi 10 sati! Nastavljamo...

Finished kite board

Finally second fiberglass layer goes on top! I've decided to finish glassing with the proper breather and bleader fabric and what a difference!
This fabric is really cheap, just a few bucks for couple of meters. Now, vacuum bag is a different matter! Since I'm using a tick vinyl for my vacuum bag, it is possible that the fabric won't bridge the gap between two layers, marine ply and bamboo. But than, the proper thin vacuum bag fabric is so difficult to work with that I've put everything in my vinyl bag. This means the proper vacuum fabric bag inserted in my bag and applied vacuum.
The reason for this is that I just couldn't apply the vacuum on a new 'proper' bag:(
And since the time is important while doing it the only option was to quickly use my proven solution for vac bagging.

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Konacno stavljen zadnji sloj fibergalsa na gornju povrsinu daske! Odlucio sam zavrsiti taj proces sa profesionalnom 'breather' i 'bleader' tkaninom i to zaista vrijedi!

Tkanina je jeftina, nekoliko dolara za par metara. No, vreca za vakum je druga prica. Kako sam koristio dosta debeli vinil kao materijal za vrecu, vinil se vjerovatno ne bi dovoljno savinuo izmedju dva slojeva sperploce sto cine dasku. No, vrlo tanak materijal za 'pravu' vakumsku vrecu se pokazao kao tazak za raditi, pa sam na kraju sve zajedno stavio u 'moju' vinil vrecu. Sto znaci 'prava' vreca u vinil vrecu i tad pod vakumski pritisak. Razlog tome je sto jednostavno nisam mogao dobiti vakum na novoj 'pravoj' vreci od vrlo tankog ali cvrstog materijala.

I kako je vrijeme jako vazno dok se to sve radi , zadnja je opcija bila da brzo vakumiram sa dokazanim postupkom.

I'm using a special super clear epoxy as final fiberglass resin. Around 52 grams.

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Koristim poseban bezbojni epoxy kao zavrsni sloj uz fiberglass. Utroseno oko 52 grama.

Proven vacuum quick release  clamp:) A bit of Blu Tack around. Need to make this better for next time. Also notice VERY important thing which is a perspex leftover with a small hole in the middle and channels like X under. Without this the 60 cents vacuum plug can't stick on vinyl vacuum bag!
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Dokazan nacin spajanja vakumske pumpe. No, moram sistem jos doraditi. Primjetite znacajnu stvar sto je komad pleksiglasa sa malom rupom u sredini i kanalom kao slovo X ispod. Bez toga par kuna vrijedan vakumski priljepak se ne moze priljepiti za vakumsku vrecu!

Vinyl vacuum bag sealed this time with Blu Tac. Quite faster than using a tape. And reusable too!
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Kompletna vakumska vreca zatvorena je 'plastelinom' tj. slicnim materijalom. Puno brze za raditi nego selotejpom i mogu ponovno koristiti!

Too much of epoxy resin going out through perforated breather fabric. This is exactly what we want! Note, applied vacuum of around only 15 mm of mercury. You can see the vac pump under the bag and a white breather fabric...
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 Visak epoxya izlazi van kroz perforiranu foliju i to je upravo sto zelimo! Ovaj puta koristio sam 'samo' pritisak od 15 mm zivine vage. BIjela tkanina je 'breather' - za disanje.

Vacuum applied. Didn't have a time to remove my plaster mold from it...Roller used for pushing epoxy into the fiberglass.

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Vakumska vreca. Nisam imao vremena ni da izvadim gipsani otisak iz vrece...Valjak je koristen da se epoxi dobro upije u fiberglass.

 

Final kite board after black paint and varnish on top and bottom. Mirror shine!

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Zavrsena daska nakon farbanja crnom bojom i zavrsnog zastitnog sloja vodootpornog laka. Sjaj kao zrcalo!

Board in action on river mouth ( 25 Dec 2011, Denmark, Australia )

Board details: 

• 135.5/41.5 cm
• Rocker 4.2 cm
• Concave 5 mm 2/3 of length, tips no concave
• Weight 2.8 kg no accessories
• Bamboo top 6 mm
• Marine ply bottom 6 mm
• Flex comparable to Xride 2009 133/39cm

The Rocker and first impressions - Prvi dojmovi i zakrivljenost

The first impression is - BEAUTIFUL!

You can't really see the shine, might be better with my other camera! But shine it is.

I'm still not finished! The last fiberglass layer on top to go! It will happen this days and than I'll reveal the top side of my new board! Yeah, sorry about that for keeping you waiting!

There are many things what I can show here but more important than anything is The Rocker. It's just as designed by my plaster mold. Not taking into the account some spring back of a ply wood might reduce the rocker a little bit.

But it's been more than 10 days since gluing and a spring back is about 2-3 mm! Which is great! I'm expecting to reduce some spring back even more with a new fiberglass layer.

The commercial board is on the right hand side. The wooden one is my work!

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Prvi dojam je - PRE KRASNO!

Ovdje se ne vidi sjaj drveta no pokusati cu boljim aparatom!

No, nisam zavrsio dasku. Jos jedan sloj fiberglasa ide na gornju povrsinu! To cu pokusati ovih dana i nakon toga cu pokazati kompletnu dasku. Zao mi je, ali morati cete se strpiti!

Ima nekoliko stvari koje bi ovdje iznio no najvaznija je zakrivljenost, tzv. Roker! Proizasao je upravo kako sam i ocekivao sa mojom sablonom od gipsa. Nisam uzeo u obzir savijanje daske nazad i to ce svakako malo ublaziti zakrivljenost.

No sada je vise 10 dana proslo od lijepljenja i zakrivljenost se umanjila za svega 2-3mm. Sto je odlicno!

Ocekujem da cu sprijeciti daljnje izravnjavanje sa novim slojem fiberglasa.

Kupovna daska je na desnoj strani. Drvena daska je mojih ruku djelo.

Fiberglass layer - sloj fibreglasa

A few nights ago I've made my first fiberglass attempt. Well, sort of. The first few runs were with my test ply wood and I strongly encourage everyone to sort this out before you fiberglass your real project.

For example, on the test run I've a used 'some' peel fabric (bleeder) and a Dacron fabric (breather). This proved wrong since the bleeder was not the right one and a Dacron fabric glued to the wood through the peel fabric.

The result was a 'hairy' ply wood, and impossible to sand off. Imagine an 'hairy' kite board:)
Like, "my board is so old that it grew a beard":)

After first test attempt, I've made a trip 'around a corner' to the fiberglass shop and bought some real peel fabric and real breather. All together around $15 for 3 meters.


So here we go:

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Prije  nekoliko noci uradio sam prvi pravi fiberglas pokusaj. Recimo. Prije pravog pokusaja napravio sam par probnih na sperploci i svakako bih predlozio da uradite isto prije nego glasirate glavni projekt.

Na primjer, tehnika glasiranja kaze da morate koristiti dva materijala izmedju fiberglasa i vakumske vrece - bleeder i breather (hm, kako ovo prevesti?). Ja sam odlucio koristiti neki materijal za koji mislih da ce biti dobar. No nije. Umjesto da se materijal lagano odlijepi sa fiberglasa kad se ljepilo stvrdne, on se je potpuno zalijepio (Dacron) i sperploca je ostala 'dlakava'. Nemoguce za odstraniti.

Zamislite 'dlakavu' dasku:)

Ono, kao, moja je daska tako stara da je pustila bradu :)

Nakon ovog pokusaja otisao sam do obliznjeg ducana sa fibreglas materijalima (ima toga ovdje:) i kupio pravi bleeder/breather (oko $15 za 3m).

Onda krecemo:

Also, on the test run my vacuum bag was sealed well since it was just a small plastic sealing bag. My 'suction valve' was working perfectly since the bag was well sealed!

Now, on the real attempt the vac bag was *not* sealed properly resulting in two or more hours wasted precious epoxy working time! The reason why wasn't sealed was a sellotape around the bag sides! When I finally found the cause it was getting late and couldn't run my vacuum pump for much longer (not having a garage or a 'man' shed doesn't help with a man's projects).



I don't have any more photos of the process. Was too stressed out knowing that the epoxy workable time was disappearing and not knowing why can't apply vacuum.


Learned lessons:

Check for the leaks! And check again all around the edges of your vac bag! Or better, permanently seal the sides on vac bag. And start working early in the morning.


Next time, the result. And, almost a perfect one...

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Na probnom pokusaju moja vakumska vreca je bila potpuno zabrtvljena, jer sam koristio malu vrecicu sa vakumirati hranu. Time je i moj ventil dobro radio jer je vreca dobro bila zacepljena!

Kod pravog glasiranja vakumska vreca nije bila dobro zabrtvljena cime sam izgubio dva ili vise sati dragocjenog radnog epoxi vremena! Vreca nije bila dobro slijepljena selotejpom jer se isti u medjuvremenu odlijepio sa strane! Kada sam konacno pronasao gdje je odlijepljeno vec je bilo dosta kasno te nisam mogao imati upaljenu vakumsku pumpu dugo vremena (nemam garazu sto bas i ne pomaze kod muskih projekata:).

Tako da nemam vise slika jer sam bio previse iznerviran znajuci da je sve manje vremena za rad sa epoxijem.

Sto sam ovime naucio:

Provjeriti gdje vreca pusta! Nekoliko puta. Ili bolje, trajno zalijepiti vrecu sa strane. I svakako poceti rad rano ujutro!

Slijedeci puta gotova daska! I to skoro pa perfektna...

Vacuum bag - vreća za vakum

Nakon uspjesnog vakumiranja testne sperploce sa fiberglasom, doslo je vrijeme glasirati pravu dasku.
Postoje samo dvije vrste materijala - PVC ili poliuretanska plastika za vakumsku vrecu. Ja sam odabrao vinil, dakle PVC plastiku koju sam imao od prije. Vinil je 1mm debljine i dosta je tvrd, no biti ce dugotrajan!
Trebati ce vam dosta velika plastika. Ovaj vinil je oko 180 sa 120 cm. Preklopljen je po duzoj strani dakle dobio sam 180 sa 60 cm radnu povrsinu tj. vrecu.

Neko sam vrijeme razmisljao kako zalijepiti stranice vrece no previse komplicirati ne vrijedi. Jednostavno sam selotejpom zalijepio dvije strane, a obostranim selotejpom stranu kroz koju sam umetnuo gipsani otisak i dasku.

Prije nego sto vakumiramo potreban nam je neki ventil koji spajamo na vakumsku pumpu. Stari, nevaljni ventil od auto gume i jedan kupaonski ili kuhinjski priljepak za keramicke plocice je dovoljan. Ventil od auto gume sam skratio i izrezao nepotrebnu gumu do pola ventila i skroz do zeljeza.. Kuhinjski priljepak sam probusio te umetnuo dovoljno ljepila i ventil. Gotov ventil na lijevoj strani zgleda ovako:

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After successful test vacuuming  with a wood ply and fiberglass, it's a time to go with a final board. There are two different vacuum bags - PVC or polyurethane plastic bags. I would suggest grab a vinyl sheet from a balcony blinds supplier. I went with a 1mm thickness,  quite tick but strong and paid only $5! You will need a sheet at least 180x120 cm so you can fold it to get 180x60 cm of working vacuum bag.

Some sites suggest gluing with a plastic cement but it's too complicated. I just used a duct tape on two sides and a double sides tape on the entry side of my bag where I've put a plaster mold and my board in.

Before we go with a vacuum we need some kind of valve for connecting a vacuum pump. Old, used auto tires valve and one suction cap for bathroom or kitchen is more than enough. Tyre valve I've cut and removed half of rubber to get to the metal part and on the suction cap drilled a hole (actually cut the top of it - it's got a hole already). Than poured some PVC cement and a valve in a suction cap. Finished valve is on the left side:

Zatim sam probao vakumirati dasku da vidim kako ce se ponasati gipsani otisak, daska i pumpa. Nesto obicne spage na dasku da vakum moze povuci zrak i to je to. Pumpa se palila svakih 30tak sekundi da odrzi vakum na oko 28 in-Hg. Ako tako radi grijati ce se, dakle pazite na pregrijavanje! Sada je sve spremno za glasiranje! Primjetite vrlo vaznu stvar, dasku sam pobrusio grubim papirom po povrsinama koje ce biti lijepljene! Inace bi moglo doci do odljepljivanja slojeva.

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Than I've applied vacuum to see how the plaster mold, board and pump will work. Some cord on top of the board and around the plaster mold to get the air out and that's it. The pump started every 30 seconds or so to keep vacuum on 28 in-Hg. It *will* be a quite hot over 24hrs! Everything is ready now for the fiberglass! Notice important thing, around gluing areas ( ie. foot pads) I've used a medium sand paper, otherwise there might be some de-laminating after glassing.

Fiberglass & Epoxy #3, test run - testiranje ljepljenja

For a long time no news from me! It doesn't mean I wasn't working on my kite board, for example I've needed a quite some time to finally finish my vacuum pump before glassing my board!
The reason - vacuum advance device from an old carburetor wasn't working as expected. And to source another one in Perth is no mean feat.
Than, I've spent some time thinking how to glue the two layers of my board. The decision is to try first with a two peaces of exactly the same wood. Routed similar holes in it as well.
This is how it looks like:

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Dosta je vremena proslo od zadnjeg clanka! No, ne znaci da nista nisam radio po pitanju izrade daske za kajtanje, vec je trebalo vise vremena da zavrsim vakumsku pumpu prije lijepljenja daske!

Razlog kasnjenja je neispravni vakumski dio od starog automobila koji je dosta tesko nabaviti ovdje gdje zivim.

Nakon toga, dosta sam razmisljao kako da zalijepim dva slojeva daske. Odlucio sam napraviti probu od dva komada istog materijala u kojima sam izradio slicne otvore.

Evo kako izgleda:

I will be using the most common epoxy for fiberglass  105A & 206B. This is my third epoxy product since already got the epoxy for gluing and epoxy for sealing. The expense now just for this three products is around $130AUD but hoping this will last for 3-4 boards. That is, if I'll make that many:)

The fiberglass cloth is  4oz and thinking to use 2-3 layers between plywood layers only in the middle of the board and under the footpads as well. Two layers diagonally at 45 degrees and one straight. Not sure if will be glassing both finished sides of the final product. Probably only top side anyway.

All of this might try on a test run. Hopefully, will go well!

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Koristiti cu uobicajeni epoxi za fiberglass 105A i 206B. Ovo je treci epoxi proizvod koji sam kupio jer vec od prije imam epoxi samo za lijepljenje i epoxi za brtvljenje. Sve su to drugaciji proizvodi za drugu namjenu. Trosak za sva tri proizvoda je sada oko 130$Au, no nadam se da ce trajati za 3-4 daske. Ako ih toliko napravim:)

Fiberglass tkanina je 4oz tezine i razmisljam koristiti 2-3 sloja izmedju sperploce kroz sredinu daske i ispod vezova za istu. Dva sloja dijagonalno polozeni i jedan ravno. Nisam siguran da cu glasirati obje strane gotove daske. Najvjerovatnije samo jednu i to gornju stranu.
Sve to mogu isprobati na ovom uzorku. Drzim palceve!