CB Sled Poly Dogboxes

 

CB Sled dogboxes are made to order from specially formulated polyethylene sheet material assembled using a unique system of "hook & slot" joints that virtually eliminate mechanical fasteners from the structure.


Photo1: Vent Holes & Locking Bar, Hooks & Slots






 Typical plywood construction uses wood cleats in the corners, 12 per box, so a 20-hole double-deck box requires 240 cleats. Each cleat needs at least six screws, for a total of nearly 1500 screws. These screws must be installed inside the boxes, which is not an easy place to work. The elimination of this difficulty and the problems caused by this assembly technique were key points of the CB Sled dogbox design.

 The hook & slot joint system not only eliminates many hundreds of parts, but also greatly simplifies and reduces the time, tools and skills required for assembly. This makes the shipment of knocked down boxes feasible, which is unheard of with any conventional dogbox construction. The high precision manufacturing required to make the joint system fit together properly is accomplished by our use of CAD/CAM design and a CNC router. This capability also allows us to quickly and economically design and cut complex vent hole designs, custom graphics, and complete custom dogbox and cage bank systems.


Photo 2: Custom Graphics




 

Material

The polyethylene material offers many advantages over marine or even expensive fiberglass-coated plywood for dogbox construction.

 

 

Even fiberglass-coated plywood is susceptible to moisture damage, fatigue, and rot at screw penetrations and edges. These problems cannot be solved by coating, only postponed, and coatings degrade quickly where there is trapped moisture. Dogboxes are exposed to extremely harsh environmental conditions, including long term exposure to salt water and sand spray while traveling. The material which has been chosen for CB Sled dogboxes was designed for continuous weather exposure and abuse resistance, as a material for the construction of playground equipment and signs. It is essentially a weather resistant version of the material of choice for wall surfaces used in modern dairy barns, where sanitation is of the utmost importance.


Photo 3: Many Colors Available






Our standard construction uses .400 inch thick textured finish solid color material, which is available in eight colors, for the roof, .125 inch thick smooth surface black for the interior dividers, .250 inch thick smooth surface black for the floor, and .500 inch thick multicolored textured finish material for the sides. This new material is co-extruded with thin layers of one color on each side over a core of a different color. Since it is made in one piece, it will never delaminate. It is available in eleven color combinations with surface and core colors that match many of the solid color shades. The colored core produces a striking effect around doors and vent holes, as well as providing limitless possibilities for maintenance-free CNC engraved graphics. More area for graphics can be had by making the rear panel from multicolored instead of solid color sheet. The material comes in 4' x 8' sheets, so designs should take that sheet size into consideration for cost efficiency. Sheets can be joined together to produce boxes larger than eight feet, and these joints are invisible on the finished boxes.

 

While the poly is roughly twice the density of plywood, since thinner pieces can be used and accessory parts and materials are minimal, the overall weight of a CB Sled poly dogbox is comparable to a similar plywood box, and substantially lighter than a fiberglass coated plywood box.

 

The polyethylene material is a highly evolved, well tested, extremely durable material. The probable limit to its lifespan is, as it is for many polymeric materials, UV exposure. This material is designed for many years of maintenance-free service in continuous outdoor use, but its useful life will be greatly extended if it is protected from unnecessary UV exposure during the off season. If cared for reasonably well, these boxes will last a lifetime, but if disposal is necessary, the material is recyclable as #2 HDPE.

 

Design & Construction

 

 


 Photo 4: Interlocking Construction, Drainage, and Door Hardware






Hook and slot assembly is a simple technique in theory, but as applied in a CB Sled dogbox it becomes a system of interlocking parts. The inherent flexibility of the material allows us to play some tricks with it that would be impossible with rigid material such as plywood. When complete, the assembly forms a fully interlocked self-contained structure. Mechanical fasteners are used in the structure only as retainers, not as primary load-bearing parts. The only mechanical fasteners used in the box pictured above are on the door hardware, and in the wooden parts. All structural loads are carried by the poly parts, which distribute stress very effectively.

 

The joint designs eliminate many moisture trapping lap seams, while providing sealing areas where needed, and moisture will not soak into or damage the material in any way, even on the cut edges. Plywood is unsuitable for use with this joining system since the hooks would be weak, easily damaged, and rot-prone. All of the main joints are constructed using "cap strips" which slide under the hooks and are bedded in sealing compound, producing watertight joints for the roof and the floor.

 

Drainage holes are provided along the sides, on top of the floor, making it easy to spot soaked bedding, and keeping any drainage out of the truck bed on pickup bed-top boxes. The roof and floor(s) are arched with a 1 inch drop from the center to each side, so the boxes will drain regardless of whether they are parked level or not. The arched shape also stiffens the parts, so there are no sags that could pool drainage inside the boxes.

 

Because crating & shipping a fully assembled dog box is prohibitively expensive, one of the key design points for CB Sled dogboxes was to make them easy enough to assemble that they could be shipped knocked down and assembled by the customer. We joke that all you need to assemble them is two dumb dog drivers and a mallet. This is not far from the truth. The basic box assembly requires only those things and a caulking gun. The finish assembly also requires a cordless drill and a few bits, but that's about it for tools. All parts are test fitted before shipping so there won't be any surprises during assembly.

 

The latches are designed and manufactured by CB Sled, specifically for dogbox use. The latch bodies are CNC milled from the same UV resistant HDPE sheet as the floors. They pivot and latch on nylon bushings which are secured to the box with stainless steel hardware. They are completely corrosion resistant. There are no loose parts, and no keeper clips are required due to the positive self-latching action. They cannot be knocked open by dogs or rough roads. The latch bodies also function as the door stops to keep the doors from getting pushed into the boxes, so no additional stops are necessary.




Photo 5: Specially Designed Latches




The operation is quick and simple: A 45° turn counterclockwise to open, clockwise to close. When closed, there are two separate detents holding the latch closed. When open, there is a detent holding the latch in the fully open position so it will close cleanly every time. The standard handles are plastic, with wood and stainless steel handle options available. Regardless of the handles chosen, the latches are easy to operate even with cold hands and mittens. To the best of our knowledge, these are the only latches available which have been specifically designed for dogbox use.

 

The acetal and stainless steel door hinges feature a positioning system that holds the door in a 115° open or a fully closed position. In the open position, they do not interfere with the adjacent door, and they will open past the detent to nearly 180°. You can open a door, then pick up a dog without having the door shut itself in the meantime, even if the wind is blowing or you are parked on a hill. They are attached through the doors and side panels by stainless steel hardware. There is no protruding hardware on the inside.

 

Locking bars can be provided in a number of different configurations, from concealed internal or external sliding bars to flaps in wood or poly. Since such variety is possible, all are optional. One type is visible in the vent hole photo above, and the photo below

 


Photo 6: Integral Roof Rack






The roof rack frame parts are precisely cut to match the curvature of the box. They are standard because they cover and protect the hooks which penetrate the roof and they create a sealing area around those joints. They also provide a nice flat, easy to work with base for whatever sled holders or racks might be desired. Keeping sleds off the roof protects both the roof and the sled. A piece of steel tubing secured in holes drilled near the ends of the rack frame can form a full-length tiedown bar on both sides of the roof on the higher profile style.



Matching wood ribs which fit under the box are included. These also create a flat surface for ease of handling and mounting. None of the the wood parts are structural, they are merely convenient. The boxes are complete self-supporting structures on their own. The wood parts are available in any number of different species and grades, from "2 by" pressure-treated stock to cherry, and are normally supplied varnished.

 

Pricing & Availability

 

Since there are so many options, not the least of which is size, there is no real "standard" model. Each CB Sled dogbox is constructed to order. They are therefore priced to order. Basic 8-hole full-size pickup bed top boxes can start at under $2500, not including either crating & shipping or assembly & installation. Any box can, of course, be preassembled and picked up, or you can help asssemble it here. Shipping costs vary depending on distance, but are at least $100, and can be $600 or more to Alaska. Truck shipping is normally FOB Littleton, NH, 03561,via Yellow Freight.

Normal lead time is 6 to 8 weeks. A 50% deposit is required when placing an order, with the balance due before shipment or at pick-up, or within 30 days of notification of completion if pickup is to be delayed. Orders unpaid after 60 days from notification will forfeit the deposit and be subject to sale.