C. FABRICATED ACCESSORIES

Specially fabricated accessories can add capability to any trailer, making it versatile and useful as initially intended. If you start with a basic trailer, I recommend bolting as many accessories as possible. The chances are very great you’ll want to use your trailer for something you never imagined. I have also found light weight materials advantageous for accessories as a way to keep the weight of the trailer to a minimum. It is amazing how quickly accessory weight can cause the overall weight to creep up into an undesirable area. 

Fabricated accessories include tool boxes in any number of configurations, stakesides, overhead carriers, tire racks, saddle racks, special platforms for weld bottles or other unusual cargoes, hose reels, spare tire carriers, doors and tailgates, dividers and bins, vents and windows, kick plates, partitions, gravel guards, bins or compartments. The list is endless, and depends on the specific cargoes you intend to carry, as we have already mentioned, as well as the ultimate function of your trailer. We will discuss a few of the more universal accessories here, but for obvious reasons cannot discuss them all. 

Fabricated Accessories-Tool Boxes 

Tool or accessory boxes mounted to the tongue or over the wheels and tires can provide useful and necessary storage. Any tool box generally ends up holding lots of paraphernalia, some of which can be very heavy. The approximate weight is important to know so the tool box can be placed appropriately. Too much weight improperly distributed can have dire effects on trailer balance and stability. It is also a good idea to gather all the items you intend to house in the tool box and measure the space they fill. This is a good time to weigh them also. 

Figure 5.20 is a flatbed car trailer with a tool box attached to the tongue-a very popular place for tool boxes. You do need a longer tongue for this placement to ensure room for the rest of your cargo. Maybe this is a good way to ensure that a longer tongue gets built. The tool box and its weight should be included as part of your initial frame calculations, as discussed in Volume 2. Remember that a tool box and a long tongue can increase the load and thus the size requirements of the tongue material. A gusset and/or doubler may be necessary to help meet that requirement. Fender mounted tool boxes, Figure 5.21, are also a possibility. These have the advantage of being centered over the axle, so that a heavy load of tools won’t significantly affect tongue weight. As with the tongue mounted box, knowing the weight of the box material as well as the proposed components of the contents can make it easier to design a lightweight adequate supporting structure up over the fenders. 

As long as the tool box base is well supported, a light gauge steel- 16 or 18 gauge (and even 20 gauge in some instances)-is appropriate for most tool boxes and is recommended because of the significant amount of weight the box itself can add. Sheet steel is easy to bend on a box and pan brake if you have access to one. Stiffener ribs on large panels should be provided and spot welded in place. Spot welding (discussed in Chapter 6) works well for tool boxes because of its minimal heat generation. Stick or MIG welding will in most cases warp large flat steel sheets and ruin your material and the work you spent bending. Wooden tool boxes are also a possibility but usually end up being heavier and decidedly less resistant to the weather. Aluminum tool boxes are definitely light weight but may be expensive. The minimum wall thickness one would want to consider is probably .050-inches, depending on the alloy and number of stiffeners used. In this case riveting is probably a better choice for joining, although properly welded aluminum can provide a handsome product.