Here is a how to guide for beginners on how to make skis or snowbaord (or kiteboard or wakeboard).
Watch this first: https://www.youtube.com/watch?v=mRs0PawztA0
Have you decided that you finally wish to build you very own ride! Well I can tell you that there is nothing intimidating about it, and there is a lot of fun and learning in front of you! In general no matter if you wish to build a pair of skis or a snowboard, a kiteboard or a wakeboard, or for that matter you wish to have something to ride when there is no snow nor wind, like a skateboard or a longboard, the good part is that the method for building any of these is pretty similar and that you can find all the needed materials here on Junksupply.
Also, it does not matter if you have any experience with any of the materials or processes from before . Its easy to pick up all things by following youtube videos or following forums. So be ready to learn and dont be scared to jump into it.
You can also be confident that using the materials available here and this guideline you will be able to make a ride that is as good in quality as the best rides available in the stores, and further more it will be you that decides how it will, look, feel and behave.
Here is an exploded view of a ski, you will see from top down: topsheet, wood veneer or graphics, fiberglass, woodcore with some reinforcemand for the binding under foot and attached sidewalls, fiberglass, base with attached steel edges and VDS rubber.
You can do it this way or you might choose to make it your way, much less complex, it is up to you!
there are plenty of good forums out there where you can get help to build anything you want. Few of them you should visit are,
1) skibuilders.com , is a great, probably the best, and very friendly forum where you will get quality response and help fast. People there have loads of experience of building anything, but mostly work with pneumatic presses and composite fabric. Dont mind the name, you can get help on kiteboards or skateboards or anything else, the methods are all the same in essence.
2) kiteforum.com, is a forum for kiteboard builders and you can get help on anything, although most people there use vacuum bagging.
3) http://www.boardbuilders.co/, is an amazing blogg by a kiteboarder Matt from Australia. He is very talented and innovative guy who takes you thru boardbuilding with a vacuum bagging technique. Further more he started a forum there, so you will find plenty of help there.
and dont forget to youtube! Go out there and read and learn as much as you can!
In general you need to know the materials you will need and the precautions you need to take when making your own ride.
1) Epoxy, is a 2 component product that consists of a Resin and a Hardner. These when mix will start a reaction that will make long polymer chains form. The end product is called a cure and is a basically plastic. Some people call Epoxy a glue. In general you can find resins of different types such as Polyester, Vinyl, Epoxy however you should for your application only consider Epoxy as this has best mechanical properties, and when put under pressure and stress it delivers.
2) Composite Fabric, can be glass, carbon, kevlar or even basalt, hemp or other alternatives. It is in essence fibers/threads weaved together to make up a fabric. By them self they offer no function but when mixed with epoxy they give the amazing properties. These materials are characterized by their mechanical properties such as how easy they break when pulled on or how much they stretch etc.
3) Composite material, are the combination of fabric (glass, carbon etc) and epoxy. This is called a matrix. Typically the ideal ration of a cured matrix is around 40-50% (fabric to resin). You can imagine a composite as two very different materials working together to make something great.
3) Wood core and the sandwich, is the core of your ride. There are plenty alternatives. The choice of your core with the composite materials will pretty much decide the behavior of your ride.
4) topsheet and the base, are used on kiteboards or skis or similar to finish the top or base. This gives extra protection, and also on skis the good gliding abilities.
5) edges and sidewalls etc., are the other component that can be used to build your ride.
NOTE on RESIN: If any chrystals are present in the Resin, please make a warm water bath and place the Resin container in the warm water and stir til chrystals are gone. This is normal for some Resins.
The general idea
The general idea is to build something that can last for many years and take a lot of abuse without braking. This is why most people use composites in combination with wood or another core type. The idea is to make a core that will define the size and shape of the product, and then wrap it into composite materials. This way when cured, the stiff and tough composite materials along with the core give you a final product that is durable and delivers the properties that you need. To get the full benefit of the composites, you need a sandwich construction, your core is wrapped on both top and bottom with composites!
For example a core can be made of Paulownia wood or a foam core which is very lite, and gives you a lite ride. But the core this lite is not stiff at all, so when you bend it it will brake. However when you wrap it in composite material, the overall stiffness of the ride will increase so you will end up with a product that can take your weight and be durable while performing well.
In general for skis, poplar, birch or bamboo or any local wood can be used. They are hard woods that give the durability you need in this kind of sport and also take well the screws for the bindings.
For kitebaords best results are obtained with Paulownia wood.
For longboards and skateboards, Maple is popular in US since it is local, however I would suggest 1.5mm Baltic Birch in Europe.Typically if you build skate then you go 4 or 5 veneers with lenght grain and 2-3 cross grain orientation veneer for support both in lenght or width. It is showed bu several products in Europe and also with some school studies that Baltic Birch veneer is as good as Maple, support local!
You will hear about a lot of fancy mechanical terms but dont worry, it is up to you how much you wish to learn and work with it. I want describe many of them (Matrix or Flexural rigidity), but in general the best idea is to read on forums, and decide what to build by borrowing some ideals from others, and copying the build up and layup to start with. Dont let this scare you, its easy to pick up.
Flexural rigidity is what we call stiffness. It is defined by your core material, core thickness and composite materials!
Matrix, is the mixture of composite fabric and epoxy. To get best properties, you need right ratio. Typically you weigh your fabric and then you mix the same weight of epoxy!
Pot life is the time you have to work with your epoxy before it becomes gel and unusable. Make sure you dont exceed this! Be well organized!
Cure time is the time it takes epoxy to cure, where all molecules are bound, and for your ride to be usable.
Profiling the core
I get a lot of questions about profiling the wooden core so the tip and tail is nice and thin while the middle is strong and thick. Usually you can go to a local carpenter shop with a cnc machine and thy can do it for you. If you like doing it your self as most of us, you will need a router and build some kind of a jig to profile your core. A jig purpose would be
1) to hold the core secured while you are profiling it with the router,
2) to make the right profile on the wood, thin tips and tail and the desired thickness in the middle.
You can easily use mdf as the base. If you decide to use a vacuum cleaner as the sucktion device you can rout channels in the mdf and connect the wacuum cleaner or a vacuum pump to it. this however need some testing and working on. A simpler solution is to hold the core down with clamps.
Also the base needs to have some ramps on each side to make sure that your routed core has the correct thickness in the end. The remps would serve as giudes for the router, which can be placed on a piece of mdf or plywood, securely, with the hole in the middle for the router bit to go thru. The whole setup would slide on the ramps and route the wooden core underneath to the desired thickness.,,
Also if you would like some CNC machining to be done, vising few local carpenters. Many of them have CNC machines and can cut the core to your shape for like 50 euros.
Profiling your wood core might be needed if you are building a kiteboards or skis or a snowboard, so you might wish to build a setup where you can put down your core and run over it with a router, so you can get thin tips/tails and thick middle. Se here as an example, https://www.youtube.com/watch?v=ue-seCVszPo
Se this video for inspiration,
Rules of thumb
1) Use epoxy above 20 degrees C, minimum at room temperature. It is much easier to work with!
2) For every 10 degrees you raise the temperature of your layup, the epoxy cure time will half. In general a full cure takes 7days or more. But in 24h typically you will have 90% or more of a cure. If you imagine that you cured at room temperature + 10 degrees C, the the same cure will be achieved in 12h. If you imagine you cured you layup at room temperature + 20 degrees C, the same cure would have been done in 6h. Many resins cure at 80 degrees C in just 30minutes or so. Further more when you cure at higher temperatures, your resin will be more viscous, and penetrate the composite fabric better, giving better result.
3) The stiffness of your final product, total thickness of your ski/snowboard, is proportional (^1) to the composite material weight/stifness, but ^3 to the core thickness within the composite material! This means you can increase the stiffness/weight of you composite material to improve stiffness or you can increase the core thickness, however the core thickness is a much more effective way to do it. If you increase the core thickness by 10% your stiffness will go up ~30%. Read here. This also means that any thickness change within the composite sandwich is much more effective then thickness changes outside the composite sandwich (like adding some veneer on top or a topseet)!
4) Weigh your fabric and mix the same weight of Epoxy. This is a good start to get optimum fabric/Epoxcy ratio.
…basically how stiff will your design feel? It is probably the most important property of your ride. In order for you to be happy with it, the design has to be just right.
The final stiffness depends on many factors and it is very hard to guesstimate. You have so many variables that do influence the stiffness, mainly the core thickness, the composite material properties and type and also your design width and length etc. So before you start crafting your ride, it is best to do a few calculations in order to get an idea how stiff your design should be and how to build it. For this you will need to look at some rides that you already know, and use it as a reference/benchmark for the calculations/simulations. Then you can do a study on how the design changes will influence the final design properties, hence the performance, and you can tweak your design till you are happy with it.
Luckily we have a tool here that will help you estimate the stiffness/flexural rigidity and many other properties of your ride, go to our simulation page.
‘The stiffness of your final product if proportional to the composite material, but ^3 to the total core thickness! This means you can increase the stiffness/weight of you composite material to improve stiffness or you can increase the core thickness, however the core thickness is a much more effective way to do it. If you increase the core thickness by 10% your stiffness will go up ~30%. Read here.’
also note, that on wide rides, basically anything than skis, you will have to deal with the stiffness in width as well, which is pretty much unwanted and will only worsen your ride in most cases. In reality it is reflected by the flexing of the ride diagonally, that is around the length axis. So in general you can look at it as
– longitudinal or length stiffness: which is the stiffness of your ride that you wish to determine as much as possible. Do you wish a stiff and responsive ride, or a soft and sluggish ride or something in between these two extremes. This is why we do simulations/calculations.
– width stiffness: which is the stiffness across the width of your ride. In general we wish this to be as stiff as possible so that you dont have unwanted flexing in the width of your ride that will make it worse performing. In ideal situations it should be infinite, in reality we use multi-axial composite material to make it as good as it can be.
– diagonal or torsional stiffness: this is basically a combination of the first two (length and width), and since the product is always physically the longest diagonally, this flexing of the product in the diagonal direction is the result of a lack of stiffness in width. You can imagine the stiffness as vectors, and any diagonal is a combination of the two (widht and lenght, x and y). In practice you can test the ‘quality’ of your product, by testing for the torsional stiffness. Start by placing the one side of your product between your feet , tightly, and grabbing the opposite end by your hands in each corner. Then try to flex the board by your hands by pulling opposite by each hand, so that it is locked tight between your feet and is turned clockwise or counter clock wise with your hands. The better the torsional stiffness, the harder it will be to flex the ride without having to loosen your feet grip.
The most widely used multiaxial fabric, and the one proven to give best stiffness properties in width and length is 0 (zero) degree combined with +/-45 degree. It is the one with the longitudinal fibers going in the length direction, 0 (zero) degree direction, and the rest of the fibers going in the plus and minus +/-45 degree direction, which is the diagonal direction of the ride.
It turns out that just as with vectors, you can split the diagonal stiffness vector into the length and widht stiffness vectors. The contribution you can get by multiplying the magnitude (in this case the weight of the ply in +/-45 degrees) with the cosine to the angle. So if the angle is 45 degree, the cosine to 45 degree is 1/square-root(2) or 0.707, then you multiply the weight of the ply in the diagonal direction with 0.707 to get the weight contribution to the length (or 0 degree) stiffness and width stiffness.
Work in a well ventilated room and use Nitrile gloves. Then you are well off! Also rub your hands in some hand lotion, just in case you get Epoxy on you. It wont go to your skin.
The worst kind of contact is via the skin, so avoid getting epoxy on your skin. Also dont rinse it of your skin with solvants!!!! A solvant (acetone or alcohol) will remuve the skins natural oily protective layer and allow the epoxy to get into your system!
Just use plenty of soap and hot water. you will be fine.
What method you choose to build your ride depends on your involvement level and pocket size. In general you need a way to make a mold that will define the shape of your ride, then you need a way to press your materials onto this mold until the composites and epoxy cures. You might also choose to use heat, this way you will get better results. There are many methods, but here are 2 popular choices,
1) vacuum bagging technique, well basically it is what you think it is. You put all your layup in a vacuum bag, against your mold, and you turn on the vacuum device until the cure is done. This way you suck all the air out, putting 1atm pressure on your setup. Removing the air bubbles (weak points) and making the resin go deep into the materials. If you can put the layup into a box that you can heat up a bit, you will get good results. This is a cheap way to build your ride. You will need to research it, but in general you will need to build a table/mold that defines the shape of your ride and that you can suck against. Then you will need some specific materials like release film, vacuum bag, peel ply, breather and bleeder, vacuum pump etc, on order to make it work. I think the cost of this will not be over 500euros, and some of it is reusable. Go here to learn much more, http://www.boardbuilders.co/.
NOTE: A note on a vacuum pump. I often get the question about what it should be. I have really had good success with a cheap 100euro vacuum pump. It is slow, but in general they all get to achieve the same vacuum, which in ideal case is close to 1atm. So there is no need to get an expensive one unless your application requires it. I got one in my local hardware shop, 3.4m3/h, 130hp. If it runs with oil, remember to change the oil every few presses.
2) pneumatic press, is the more expensive method, that is suited if you are going to produce more then few products, perhaps sell to friends and build own brand. This method gives more consistent results and might give higher quality as it allows to press at much higher pressure and temperature. Most of the big players use this method. IF you wish to do so, dont worry, you can build all of it your self, it can be low level or high level version, but here is a good guide on how and what if you wish to build something everlasting and have some $$$ to spend, Happy monkey skipress. This will probably cost you around 3-4.000 euros. A good video that gives you an impression of what I am talking about and what is involved can be viewed here. If you decide to build this baby also take the advantage of skubuilders.com, then you will make it for sure.
The most important thing when building your own ride is to be well organized and have patience. Make sure you have all the tools, machines at hand and that all the materials are sorted and cut into the right dimensions, and also it helps if they are laying in the right order so once you start working with the epoxy and the layup, your work will flow with no stops and you can work effectively.
You can read the HOW TO on the http://skibuilders.com/howto/
how to build Kiteboards or wakeboards
Materials: Core, Epoxy, composite fabric, inserts, topsheet. If you will do vacuum bag technique you will need a pump, some film and/or a bag, release agent, peel ply and some breather.
Machines: Jig saw, drill, router, sander or sandpaper.
1) Figure out the shape of your kitebaord and the shape of your mold. Make the mold by using some of the techniques available.
2) Cut the channels onto the kiteboard. The channels are filled out with epoxy or PU material and they make out rails which later protect the board from water and impact. You can alternativelly make sidewalls/rails from UHMW-PE or PU or ABS materials. This is really up to you, what method to choose.
3) fill out the channels by epoxy or polyurethane filling. let them harden
4) Profile the core thickness.
5) put inserts and fill with epoxy
6) Prepare materials, topsheet, epoxy, fabric. Arrange , organize and cut to shape needed.
7) Mix epoxy resin + hardener. Mix it by weight of hardener and resin. Mix for 2 minutes well. In the beginning the mix is foggy, but after well mixing and scraping sides, the mix will become clear. Now you can work with Epoxy for the pot life of it! Dont exceed this!
8) put topsheet, then your graphics if any, then glassfiber layer, woodcore , glassfiber, graphics, topsheet.
9) put onto mold and put pressure on, let cure.
10) take out when fully cured and finish. At room temperature this can be 24h or more, but at heated setup it can be as low as 30min depending on your setup.
how to build Longboards or skatebaords
Materials: Core/veneer, Epoxy, composite fabric if wanted, topsheet if wanted. If you will do vacuum bag technique you will need a pump, some film and/or a bag, release agent, peel ply and some breather.
Machines: Jig saw, drill, router, sander or sandpaper.
1) Figure out the shape of your longboard and the shape of your mold. Make the mold by using some of the techniques available.
2) Prepare materials on the right order: core, topsheet, epoxy, fabric. Arrange , organize and cut to shape needed.
3) Mix epoxy resin + hardener. Mix it by weight of hardener and resin. Mix for 2 minutes well. In the beginning the mix is foggy, but after well mixing and scraping sides, the mix will become clear. Now you can work with Epoxy for the pot life of it! Dont exceed this!
4) put topsheet, then your graphics if any, then glassfiber layer, woodcore , glassfiber, graphics, topsheet or if veneer only then just put the layers of veneer.
5) put onto mold and put pressure on, let cure.
6) take out when fully cured and finish. At room temperature this can be 24h or more, but at heated setup it can be as low as 30min depending on your setup.
how to build Skis or snowboards
Materials: core, base, sidewalls, steel edges and VDS rubber, composite fabric, epoxy, top sheet or final wood veneer and some superglue/woodglue. Inserts and binding reinforcement if needed. If you will do vacuum bag technique you will need a pump, some film and/or a bag, release agent, peel ply and some breather.
Machines: Jig saw, drill, router, sander or sandpaper.
1) Figure out the shape of your ski/snowboard and the shape of your mold. Make the mold by using some of the techniques available.
2) Cut the core to the shape. Make sure you take into account the width of the sidewalls if any.
3) glue the sidewalls by any glue usable (epoxy is good). Make sure all is bit wider then needed as later you will cut the excessive material and it will aligne well witht he base/edges.
4) Profile the core.
5) Prepare materials, topsheet, epoxy, fabric. Arrange , organize and cut to shape needed.
6) put tip/tail filler if any, onto the core.
7) cut the base to the shape.
8) cut and glue the steel edges to the base. The glue is super glue, nothing special. Since the edges will add to the overall widht of the base, make sure the base is shorther for the width of the edges .
9) Mix epoxy resin + hardener. Mix it by weight of hardener and resin. Mix for 2 minutes well. In the beginning the mix is foggy, but after well mixing and scraping sides, the mix will become clear. Now you can work with Epoxy for the pot life of it! Dont exceed this!
10) put base (with edges glued), top the steel edges and critical areas with VDS, then glassfiber layer, woodcore , glassfiber, bindings reinforcement, graphics, topsheet.
11) put onto mold and put pressure on, let cure.
12) take out when fully cured and finish. At room temperature this can be 24h or more, but at heated setup it can be as low as 30min depending on your setup.