Having a car trailer can be very beneficial, especially if you are planning a move or if you haul a lot of items--or you often go drag racing. Fortunately, you can build a car trailer quickly once you have the parts and tools gathered together.
Construct the floor frame. You will use the angle iron to create a 6-foot by 10-foot rectangular floor frame. Cross brace the frame with three angle iron bars that cross the frame at the 2 1/2-foot, 5-foot and 7 1/2-foot marks. Spot weld all joints making sure you weld all the way around. Flip this frame over before moving on to the next step.
Find a used axle and wheel assembly that is already connected to a towing tongue. You can find these at junk yards and salvage yards for a reasonable price. This step is going to save you a lot of time and money when building a quick car trailer. Once you have your axle and wheel assembly at home clean it up, making sure you remove all of the rust spots and patch and spot weld holes in the frame.
Attach the flooring frame to the axle and wheel assembly by spot welding it along all the points of contact between the two components of your trailer. Put on the wheels and tires and then flip the unit over with the help of one or two people.
Build side walls for your car trailer. You will first want to lay down some plywood to create the base of the trailer. Next you will box in the base with 1-inch by 4-inch boards. You can simply nail together the 1x4s or you can use metal brackets to join the corners together. If you want, you can add a hinge to the back board so that it can be lowered to make loading the trailer easier to do.
Read your local laws regarding the construction and registering of car trailers to make sure you aren’t breaking any laws with your homemade trailer.