YOU ALSO CAN BECOME A SHAPER. THE GUIDE
PART II - SHAPING
Chapter 1 - GIVING THE RIGHT SHAPE TO THE BLANK
L the first phase of the actual work will be to give the final shape to your blank or polystyrene block, that is to say "shape" your table. First of all, if you have chosen a polystyrene block and want to insert a stringer, you will have to start from here. If, on the other hand, you have opted for carbon or other special fabrics, following our advice, or you have got yourself a beautiful PU blank, you can skip this step.
1. INSERT STRINGER
As a glue you can use a vinyl, an epoxy glue or even the epoxy resin that you have available for the table. There are several techniques, we point out one:
- Print your rocker profile, using a plotter or glue by joining the various printed sheets precisely following the guidelines. Better if you build yourself a masonite template as we have explained previously, or cut out the design and glue it with a glue stick on the wood you have purchased.
- Trace the profile of the stringer on the wooden panel.
- With a jigsaw, stand slightly off the line by securely fixing the model to the bench to keep it from vibrating.
- With a file, or with a surform plane or a medium / coarse sandpaper, depending on how far you are from the line that represents your project, approach until you reach the goal. You can choose to stay 2/5 mm away from the line, both at the top and at the bottom, if you are not sure if you can do a precision job in the next step. In this way you will reproduce a blank similar to the PU, which you will go to work again later by tracing the rocker profile on the sides, which we will explain later.
-Next take your glue, being careful not to overdo it to prevent it from falling on the sides of the blank that you will have to shape. With a brush, spread it trying to stay inside on each edge of about 1cm / 1.5cm to prevent the glue from coming out of shape during pressure.
If you have opted for a vinyl glue or epoxy resin, I recommend a double step: take the stringer and place it perfectly aligned on the track you have previously marked. Using weights, evenly press the stringer to the block. Wait half an hour, the time necessary for the stringer not to slide easily on the blank, and you will place the other block of EPS, also perfectly aligned on the stringer.
With epoxy glue, you can do the entire bonding in one step.
Once you have aligned the blocks with each other, you will have to press everything, so that each element is well adherent to the other, and perfectly in line. Here everyone uses what they have. Large weights can be achieved with many types of objects, from books to bricks to gym weights. The pressure must be large and even. It is also possible to use numerous snap straps, paying attention to the sliding of the edges. The ideal solution would be to get one-handed screw clamps, or even carpenter's clamps with at least 600mm of opening. Once you have found the right position, let it dry well.
If you have opted for the insertion of the stringer in EPS blocks, the following steps, the Outline and the Rocker Profile can be reversed.
2. THE OUTLINE
TRACKING THE OUTLINE ON THE BLANK: The outline is the outline of your board. If you are not going to spend the time making a cardboard or masonite template, s buffer all the components of the template and cut the sections. Set the smallest possible print margins so that you use as little paper as possible. Try to cut the outline as close to the line as possible, but never inside. Tap the printed sheets of paper together following the markings that are printed on each sheet for proper alignment.
Once the project has been reconstructed in full size, if you do not intend to build a Masonite template, you can simply place the paper outline template carefully on the bottom of the blank to trace the outline directly from the paper.
Align the straight edge of the template along the axis of symmetry (which can be the center of the wooden stringer or a line previously drawn by you if you have decided not to use wood) and adjust the exact position of the template with respect to the length of the table. In the case of PU blank, where the rocker profile is already roughly pre-set, the alignment phase along the symmetry axis is fundamental. In fact, in these cases the blank will be longer than your template, and if you slide the template forward on the blank you will get more rocker in the nose, while sliding it back towards the tail will give you a flatter rocker. Same thing goes for the tail, so you have to be good at managing positioning, as well as having chosen a blank more similar to your project.
Once the model is aligned in the right place, simply hold flat on the blank and trace the outline on the foam using a pencil. Then the model is turned over, centered on the axis of symmetry maintaining the previously chosen position, and the other side of the table is drawn. It is essential to make sure you have the same position on both sides to ensure the symmetry of your profile. You can verify this with your shaper's square.
OUTLINE CUT: Once the outline is drawn on the bottom of the blank, you need to cut the scrap. Using a hand saw is the preferred way of all shapers, because it is still quick and easy. If you want you can use a jigsaw with an elongated blade; this will guarantee you a cut closer to 90 degrees than the block.
Being very careful, with the blade as perpendicular as possible, you will have to cut your outline trying to stay outside the line by at least 3 mm to have some margin for any errors. Going beyond the inward line is a mistake that has no remedy other than the one that goes through changing the size of your board. The closer to 90 degrees your cut is, the easier the following procedure will be.
SQUARING AND SANDING THE CUT OUTLINE: Once the outline is cut, a careful squaring of the cut is required. The most suitable tool to do this job must be chosen based on your skills and the financial resources you have decided to use on your project. Most shapers use an electric plane. You can use a Surform, or the series of hard blocks with abrasive paper, or better yet a tool that you can simply build with two wooden blocks glued at 90 °, inside which you will glue some coarse-grained abrasive. With a vertical team you can control your work.
- Place your blank inserted vertically in the saddles of the racks (it also works flat using weights to hold the blank in place).
- First of all, with the chosen tool, you will remove all the material to create a smooth surface, free from depressions.
- After that you will have to carefully approach your line drawn on the blank deck by creating a soft outline curve and being careful to keep it as close to the 90 degree angle. The closer you get to the drawn line, the more you have to pay attention to what you are modeling. Take your time, and use your available lights to check the entire length of the rail for unwanted dips in the outline.
- Simultaneously with the approach to the curve of the outline, you must bring the two surfaces to stretch perfectly at 90 ° to each other. By scrolling the combination of teams along the rail of the board you can quickly see where the outline needs to be squared. Work here slowly, using the hard sanding block with sandpaper to flatten and square the areas of the rails . Maintain control with the combination of teams so that you can make adjustments.
- When you are satisfied with the squaring of the outline with your block you will have to gently get to make the marked line of the outline disappear, remembering that it is much more important to obtain clean smooth curves than having to obsessively chase the traced lines.
3. THE ROCKER PROFILE
Now that you have got your well-squared and smooth outline, you will need to obtain the rocker profile of your board inside your blank, which is nothing more than the curve of the board that starts from the nose and reaches the tail. If, on the other hand, you have opted for EPS blocks with insertion of stringer, it is better to start from the rocker profile and then subsequently cut the outline.
EPS BLANK: Let's continue with our EPS without outline, and then see the process with the PU blanks. Trace your profile on the two sides of each of your EPS blocks, making sure the opposite sides of your block are exactly aligned with the stringer. As for all the shaping phases made up to here, it is a good idea to leave a small space, at least 3 mm, to then allow a finishing work in which two surfaces must be obtained, that of the deck and that of the bottom, flattened and parallel to each other, as well as perpendicular to the rails. To achieve this you will have to start by tracing the rocker profile starting from one side, perhaps using your temlate or using the rocker and thickness measurements at the following points:
Tail, 3 ", 6", 9 "12" 24 "from the tail,
Center of the table,
Nose, 3 ", 6", 9 "12" 24 "from the nose.
If you have designed with a Shape3d or Akushape type program these points are easily traceable. If you have instead created a template, or inserted a stringer, the work will be easier.
In any case, these points, or some of these in the case of a template, must be marked on both edges of the table, making sure that they are perfectly aligned. You can use the shapers team, to bring each point from one edge to the other and then check the result with teams and a tape measure.
After you have marked all the points, the rocker and the thickness, on both sides and verified that they are perfectly aligned, use your template to reproduce the rocker profile. If you don't have it, join the lines with something flexible that allows you to reproduce the curves. I recommend using small pegs to insert at each point and wrap a thin wooden stick or even a fabric ribbon around them. Remember that you will have to create curves, and not obsessively follow your points. The lines drawn must be a reference point; it will do the same if in the cut of the rocker profile you have not obtained exactly the profile and the thickness traced on the blank. Don't get too involved with the signs as the flow of water doesn't care about numbers, only about curves. If in the cut and shape you have made long and precise movements you will surely get smooth and soft curves that must remain your goal.
In summary, you will have to trace the profile on both sides, in order to have a guide when planing or cutting with hot wire to obtain your profile. After gluing the polystyrene blocks with the crossbar already inserted, you can foil both the deck and the bottom. An electric plane could help you.
Manual alternative is to use the surform. Get ready to produce lots of foam around your workplace. The quickest solution would be to use a hot wire that can cut your rocker profile along the lines drawn on the edges. A very fast and precise method that could save you a lot of time, in fact self-building a hot wire is not so difficult. Go to youtube and you will find many ways to build your own hot wire for polystyrene cutting.
Once you have the rocker profile, you will need to move on to cutting the outline, as illustrated above.
As you can see, this is a tiring and delicate job, which would require more complex and therefore more expensive tools. Our solution is to give you blanks already pre-shaped by machine in outline and rocker profile. Perfect 90 ° angles and flat surfaces that you will then have to shape to your liking, leaving you all the taste of the shape by hand. The cutting of the outline but above all of the rocker profile, as far as I'm concerned, is an effort that I would gladly avoid, even if we have the idea of wanting to do everything by hand. Gutting an EPS block involves a lot of effort, dust and waste material and an ever present risk that the opposite surfaces are not perfectly parallel to each other. In fact, if you have chosen our EPS Preshaped blanks you can skip the paragraphs concerning the cut of the outline and the cut of the rocker profile and go directly to the next chapter, where you will be guided to create your rails and to dig your concave on the bottom. .
PU BLANKS: For the PU blank (or EPS not in block), we must provide ourselves with gauge and rocker stick and always refer to the project. A rocker stick is nothing more than a long straight stick to be placed along the axis of symmetry to measure the depth of the rocker once the foam is removed. It can also be used in the phase of marking the points on the edge. Perfect would be a square aluminum profile, which due to its lightness is ideal for this job.
Place it perfectly level on the bottom along the axis of symmetry, sliding it forward or backward to perfect the level point. This will be found by placing a spirit level over the rocker bar. The point where the bar touches the blank will be rocker level 0. With the measuring rod inserted vertically, a simple tape measure or a square, you can get all the rocker points. These can be drawn on the cut edge of the outline.
Once the traces of the profiles on both edges of the blank have been obtained, perfectly aligned and parallel, it is time to go and remove all the material to get to your table. The advice is to start from the bottom, so that you have already defined the rocker. It is also good to know that PU Blanks have a surface hardness that decreases as you go down towards the core. Eliminating more material on the bottom contributes to having a deck, where we will then put our feet, much more resistant. So after reaching the rocker curve (I remind you that the blanks already have a curve, and if you choose the right one you can skip this delicate step), you will have to lower the board until you get to the thicknesses chosen for your project, leaving you about 4 / 5 mm of margin to be able to work also on the deck.
Once the bottom is finished, the task of foiling the deck of the board becomes much easier, as the goal is to reach the thicknesses of your project in the center of the board.
At this stage, it is good to protect yourself with headphones, a mask and goggles. The most suitable and most effective tool, due to its speed and precision, is the electric plane. If you are not an expert and want to grow gradually without haste and above all you do not want to ruin your first blank, the advice is to use tools such as hard blocks with very large grain paper or better still the Surform capable of removing more material in less. time. It depends on the tools you have at your disposal.
If, on the other hand, you are not afraid and want to use the electric plane immediately, do it with some precautions:
- first of all study how an electric plane is made and how it works: the front plate of the plane is your reference. It must drag well adherent to the foam. The blade will cut where it passes with the thickness you decide with respect to the position of the front plate. Remember the position of the blade well. The knob manages the depth of cut, study its movements.
-to make the best use of the electric plane, I recommend that you observe Master Matt Kazuma on his youtube channel.
- a tip is to take a polystyrene block, cheap and easy to find, and turn it around until you have reached greater safety. After each pass, clean the surface by hand, and start again with a new round of cut.
- If you don't have any practice, you can help yourself by drawing guidelines with a pencil, parallel to each other at a distance of about 7/8 cm from each other, starting from the axis of symmetry.
- you can get closer to your project using a shallower thickness of cut and then finish by hand after each pass.
- always walk, light as if you were intent on getting to the nose of your longboard, don't be afraid to stay still on the foam.
When you feel like it, with the plane on, lay it flat on the edge rotated 45 ° from the direction of travel and advance along the first line near the edge. Move slowly, and when you get near the rocker zero points try to get out with the plane still on, as if it were an airplane taking off. Make yourself the whole width of the board, as if it were a lawn to be mowed, overlapping each pass by a small space. When you have reached the bottom, start with another lap. Go several times in the areas where more foam needs to be removed to increase the rocker. Adjust the depth of cut as you approach the required thickness and try to blend the cut with the simple movement of the plane or by lowering the depth of cut.
Once you have approached the lines you will have to smooth out the lines and then the entire surface of the bottom with hand tools using first the surform (if you have it available) and then the rigid blocks with sandpaper. With medium pressure, try to make long movements. Never stop for a long time on an area and try to cover the entire surface while spending the same amount of time. Use the stringer as a reference plane to hold the pressure of the rigid block. You will immediately notice at the first shaped board, that the foam comes off faster than the wood. You can then use it as a support surface to level the surfaces.
Once the work is finished you will have to check that the two side edges where you are going to make the rails, are perfectly aligned and with the same thickness. Combination of teams and rocker sticks will be your verification tools. If you find any differences in thickness between one edge and another, use your long block to try to match the thicknesses. To consider the bottom surface flat, you will need to check the perpendicularity along the entire rail edge on both sides.
Once you have obtained the surface of the bottom you will have to work on the deck so that it too is flat and perpendicular to the rails following the profile, and therefore the thicknesses you have decided for your board. The manufacturing process is almost identical to that used to obtain the bottom. The only difference is the curved shape of the deck typical of raw PU blanks already pre-shaped.
Flip your blank, with your deck facing up. If you have not already done so, draw your thickness guidelines with respect to the rocker with the combinations of teams at the points: Tail, 3 ", 6", 9 "12" 24 "from the tail, Center of the board, Nose, 3" , 6 ", 9" 12 "24" from the nose.
If you have a thickness gauge and a good familiarity with the electric plane, you can skip this phase, and make a pass with the plane over the entire surface or in the points that need to be lowered to reach the desired thickness.
Put on the appropriate safety tools, mask, goggles and earplugs and start again with the same procedure as above. Compared to the bottom, the material to be removed to get to your thickness lines will be much less, if you have listened to the advice to work above all on the deck.
You will have to work so that the surface of the wood and the foam are perfectly aligned. A small plane, well sharpened, will be of your support. A soft, medium-density pad may help you lower the foam as you pull the wood down in the center. This will be even more complicated as you get closer to the nose, where the surface becomes more and more curved. The best tool in this situation is the spokeshave, a small two-handed plane for curved surfaces to be used exclusively on wood, but you can do it carefully with any manual abrasive.
When you have reached the drawn lines or the desired thicknesses, take all your time to check the surfaces. You will need to get two large surfaces, that of the bottom flat and perpendicular to the surfaces of the edges where the rails will go, and the curve of the rocker on the deck and on the bottom clean without any dip.
4. SURFACE FINISH
If after your verification, everything went smoothly, you can move on to subsequent processing. First wipe all surfaces with a light grit sandpaper on a soft block, such as a 120 #.