Take your surfing to the next level with the GEARBOX Fin System!

There are two separate depth settings on the gauge, STANDARD (circular notch on the side) for a typical install and CONCAVE (triangular notch on the side) for installations in double concaves; this depth is 1/32" deeper than the standard install. The concave depth is deeper due to the base router jig tending to bridge the concave; the goal is to have the box flange slightly below the install cavity's lowest point. Depending on the severity of the concave, the depth might need to be adjusted from the one provided. See the EXTRAS section at the end of this page for more details on the gauge.

The depth gauge is placed on the bottom of the router base with the appropriate notch above the router bit for the desired depth - CIRCULAR Notch = STANDARD and TRIANGULAR Notch = CONCAVE, as shown in the illustration above.

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. A better install can be achieved by always having the box slightly below the lip of the routed cavity.

Doing a test run on a foam scrap is an excellent idea to ensure everything is correct before proceeding.

A trim router is strongly recommended as these are easier to handle and fit better on the jigs, but any router will work!

Routing will most commonly be performed on the shaped surfboard blank. The significant difference with this type of installation is that we will install a high-density foam block into the routed cavity. This provides a more stable support platform for the box, especially in low-density foam.

The 1Rout installation technique utilizes a single jig and HD foam blocks to house the box within the routed cavity. This technique is the simplest and is always used for low-density EPS foam installations. However, the HD foam blocks must be purchased separately for the installation.

To ease the process, a line connecting the two dots that mark the fin location should be drawn if these are not already present.

These lines will help position the jigs and are typically placed on the blank by the shaper to their desired fin layout.

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. Finally, 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.

Once the base jig is in place on the blank, the routing process can proceed. For this type of installation, we will rout a single cavity, the shape of the box, and the total depth using the standard router bit depth setting.

Start removing foam from the center of the cavity first. Then finish off by moving the router in a clockwise direction around the perimeter of the jig. This will protect the outer edge of the cavity from debris flying around inside the cavity. The resulting cut is always a 1/16” away from the jig.

Be careful when routing a center box, as the stringer can cause the router to jump, removing small amounts of the stringer at a time. Also, if there is a lot of vee in the board, some tape might be needed to hold the base jig.

When finished, please wait for the router to stop spinning before removing it from the jig; this prevents accidentally nicking the jig. Next, remove the base jig from the board.

A single cavity is now routed into the blank into which the HD foam block and box will be installed.

Use the provided hex key to ensure the grub screws are well down into the box so they cannot be touched when sanding the board. Next, cover the dams on the boxes with the provided die-cut tape or masking tape cut to fit the dam. Ensure the tape is pressed tight to prevent resin from leaking into the slot.

The HD foam block and the box will be installed into the board simultaneously in two steps.

First, the HD foam block will be installed. Start by coating the bottom and lower sides of the routed cavity with a light coat of resin. Next, push the foam block down into the cavity, ensuring it is flush with the bottom; it should look like the photo in the next step.

Now that the HD foam block has been inserted into the cavity proceed with the installation of the box. To install a box, pour some resin into the narrow cavity in the HD foam block. Please make sure all of the inner surfaces of the cavity are covered with resin and that there is enough resin in the bottom cavity to almost fill it.

Press the box down into the HD foam block and cavity, resin should squeeze up around the edges of the box and cover. Ensure 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 when installed correctly.

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 used, placing it underneath the bottom lamination might be easier. In this case, it should always be a layer of 4 oz 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.

Once the board has been hot coated and cured, 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 box slot and the grub screw holes.

If the board is glossed and polished, another die-cut or masking tape must 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.

Post-lamination installation is where the boxes are installed after the board has been laminated but before the hot coats are applied.

The advantages of this approach are an increase in strength. More time to complete the installation without the pressure of laminating the entire bottom of the board. Improvement in the strength of the bottom lamination as it is not interrupted by the box installation so that the fiberglass can be laid down more symmetrically.

The additional strength of this install technique comes from the fact that the side of the box is bearing onto the edge of the lamination once installed. This helps dissipate loads into the laminate, making it stronger.

The process is identical to standard or EPS installation techniques, except the board is first laminated before installation.

1. apply a few pieces of adhesive-backed (PSA) sandpaper to the bottom of the board and then place the base jig with its pad on the sandpaper; this will help prevent the jig from sliding
2. apply double-sided carpet tape to the board on either side of the box location, then place the base jig on the tape to lock it in place; peel off the tape when done

STEP 1

Laminate the board, as usual.

STEP 2

Proceed with the installation by following one of the previous install guides. The only difference in the process is that the routing will also go through the bottom lamination.

Boxes will still need to be capped with two layers of glass, as with the standard approach.

STEP 3

On completion of the installation, apply the hot coats as per any standard lamination.

In this case, there will be no color over the cover, so it will show as WHITE in the installation unless there is a custom or color cover, in which case the color or material will be visible!

This installation technique is also easier for anyone wanting to check the cant angle of the box. The box can first be glued into the board with a fin in the slot. This allows the fin cant angle to be checked before applying the glass caps over the boxes.

The base router jig is the primary positioning jig and serves as the host for the two working jigs (it is also utilized on other installation options; see the 1ROUT Install Guide). It has a rubber pad on the bottom to prevent slippage and protect the bottom of the board. The bottom router jig is used to rout the cavity for the bottom of the box. Finally, the top router jig routs the shelf onto which the box rests during installation. All jigs have markings on them to help with orientation and placement.

The router bit features a bearing larger than the 3/8” diameter cutter, so there is a slight offset from the edge of the jig during the routing operation.

A depth gauge is also provided to set up the router bit depth.

The depth gauge supplied with a GEARBOX install kit correctly sets the depth of the router bit.

There are two different depths on the gauge. STANDARD (circular notch), used for installs on flat bottoms, shallow concaves, or vee bottoms. CONCAVE (triangular notch), used for installations in deep double barrel concaves.

The CONCAVE depth is needed because the router jig can bridge a deep concave. When routing a cavity at the STANDARD depth, the box could end above the lip of the cavity at the bottom of the concave—making deeper cavity results in the installed box being slightly below the lip at the low point. For extreme concaves, the depth might need to be adjusted as needed. Always do an initial test rout in scrap foam.

The depth gauge is placed on the bottom of the router base with the appropriate notch above the router bit for the desired depth - CIRCULAR = STANDARD and TRIANGULAR = CONCAVE, as shown in the illustration below.

This is possible by using an alternative installation process. Instead of putting the box in during the lamination process, it can be bonded into the blank before lamination. This allows a fin to be placed in the box so the installer can adjust the box to a specific angle. To do this, the cavity for the box has to be made slightly deeper to allow the adjusted box to still sit below the lip of the cavity.

It is critical with this type of installation to ensure sufficient resin in the cavity during the installation. This is because the box will no longer be seated flat on the shelf created by the cavity. So there needs to be enough resin to fill in the space below the tilted collar of the box.

It is also possible for the more precise installer to adjust the base router jig to the desired angle. This allows the cavity to function as intended, allowing the collar to be fully seated on the shelf. It is also possible in certain circumstances to shave down the flange of the collar to better accommodate a change in angle, but this should only be done in extreme situations. When adjusting the cant angle to something other than those provided, it is advisable to use a guide to ensure they are installed precisely.

Once the boxes have all been set, the lamination process can proceed as usual.

This is a standard used by many in the surfboard industry. In addition, we highly recommend using the G Square that GEARBOX SURF sells, as this layout tool makes the process extremely easy.

The G Square has a width that is the standard 4 1/2"; once the back mark has been placed, it is straightforward to layout the front mark with the appropriate amount of toe-in, use the back mark measurement, then subtract the amount of toe-in to find the front mark. In addition, the square has a centerline that can line it up with the stringer on the surfboard.