To adjust the router bit to the correct depth, place the router upside down on a table, place the base router jig on the bottom of the router base, now adjust the router bit so that 16.5mm (21/32”) of the cutter is protruding above the rubber non-slip pad on the bottom of the jig. This results in the tip of the cutter being 1/32" (1mm) above the lip of the load bearing collar.
Alternatively, a box can be placed on the bottom of the jig, then adjust the bit until it is slightly above the top of the upper surface of the load beam collar.
It is a good idea to do a test run in a scrap of foam to ensure that everything is correct before proceeding.
NOTE: for installation into deep double concaves it is advisable to set the bit a little deeper in order to allow the box to be fully below the bottom surface, at the lowest point of the concave. A measurement of roughly 31.75mm (1 1/4” ) from the base of the router to the tip of the cutters on the router bit can be used as a starting point! This results in a cavity that is slightly deeper than the depth of the box when installed in a deep concave.
A GEARBOX 2 install is very simple and only requires our routing system, hex key, die cut tape, boxes, and a router that you provide.
A trim router is strongly recommended as these are easier to handle and fit better on the jigs, but any router will work! See the general sections for router bit setup, details about the routing system, glossary, box details, and more.
Routing will most commonly be performed on the shaped surfboard blank. But an installation can be performed after the bottom has been laminated, but the boxes will still need to be capped with glass.
As part of the setup the blank needs to have the shapers fin layout lines, for the desired fin setup.
To ease the process there should be a line drawn connecting the two dots that mark the fin location, if these are not already present.
These lines will help with the positioning of the jigs, and are typically placed on the blank by the shaper to their desired fin layout.
Place the base router jig on the blank oriented with the rail marker pointing towards the rail.
Place the back shapers mark window on the back shapers mark, then use either the centerline for a center box, or the side centerline for a side box to align the jig between the marks. Use the shapers mark crosshatch to position the mark within the window.
Typically, the jig does not need to be anchored to the blank as the weight of the jig and the rubber pad on the bottom keep the jig in place.
Place the top router jig on top of the base jig, once again with the rail marker matching that of the base jig. The top jig has a built in locater on each end that locks it into position on top of the base jig.
The router bit depth DOES NOT need to be adjusted to rout this cavity as the jig correctly raises the bit to the correct depth.
Proceed with the routing of the cavity that forms the shelf onto which the box load beam collar will rest.
Remove the top router jig and place the bottom router jig inside the base jig. The bottom jig fits precisely in the inner opening. Ensure that the rail marker is oriented the same as the base jig. The jig will not drop into the previously routed cavity as there is a slight reveal all the way around the interior.
Router bit depth does not need to be adjusted for this cut. Be careful inserting the router bit into the jig as there is not a lot of room. Start up the router and then insert the router bit into the surfboard foam. Holding firmly onto the router move it in a clockwise direction around the inside of the jig. Resulting cut is always a 1/16” away from the jig.
Be very careful when routing a center box as the stringer can cause the router to jump. It is safer to create a starter hole in the stringer to make it easier to start the router while inserted into this opening. The hole can be made by using the router before adding the bottom router jig, or a Forstner Bit can be used to made a starter hole in the string. If there is a lot of vee in the board some tape might be needed to hold the base jig.
When finished routing always wait for the router to stop spinning before removing it from the jig, this prevents accidentally nicking the jig. After routing the bottom cavity, remove both the bottom jig and the base jig from the blank. Cavity routing is now complete!
WARNING: When routing a stringer, hold the router firmly while slowly plunging into the center of the stringer, then remove small amounts of the stringer at a time to minimize the risk of the router bit catching! Once the stringer has been removed run the router clockwise around the perimeter of the jig to finish the hole. A drill can also be used to remove some of the excess wood to simplify the routing process!
With the revised notched bottom jig the cavity now already features cutouts for the screw posts so no additional work is required!
Before starting the installation the boxes need to be prepared. Start by using the provided hex key to make sure the grub screws are well down into the box so that they cannot be touched when sanding the board. Next cover the dams on the boxes with the die cut tape we provide, or masking tape cut to fit the dam. Make sure the tape is pressed down tight to prevent resin from leaking into the slot.
To install a box, pour some laminating resin into the routed cavity. Make sure all of the inner surfaces of the cavity are covered with resin. Press the box down onto the cavity, resin should squeeze up around the edges of the box and cover. Make sure the box is fully pressed into the cavity, the upper surface of the load beam collar flange should be slightly below the lip of the cavity.
WARNING: SIDE BOXES MUST BE ORIENTED WITH THE SCREW SIDE FACING TOWARDS THE STRINGER!
Spread the excess resin around the top of the cover ensuring that all cavities are filled with resin.
Now the box can be covered with fiberglass and the lamination process can proceed. An additional reinforcement patch should finally be applied over the boxes. But if a 6-oz or heavier cloth is being used it might be easier to place it underneath the bottom lamination. In this case it should always be a layer of 4-oz in order to get it to drape as tight to the dam of the box as possible.
After lamination, before the resin gels, check for air around the boxes and rub in extra resin, if needed, to remove any air, or use a pin or scratch awl to pop the air bubbles.
NOTE: there should always be at least two layers of fiberglass over the boxes. The additional layer should always be placed on top of the bottom lamination. Ideally, the second layer should be added after the bottom has cured, but it can be applied with the bottom laminate.
During the lamination process the box is capped with layers of glass, some of which is designed to be removed during the sanding process.
Once the board has been hot coated and has cured it is time to sand the board and boxes. The shape of the dam on the box creates a raised area that needs to be sanded down flush with the bottom surface of the board.
Sand down the protruding dam on the boxes until it is completely flush with the bottom of the board. This will expose the slot of the box, and the grub screw holes.
If the board is going to be glossed and polished another die cut tape, or masking tape, will need to be applied to the top of the box to cover the exposed slot and screw holes. Now the glossing process can be completed. Once the gloss coat has cured the board can be polished as with any other fin system. Remove the cover at the end of the process to keep the box slot clean.