DIY Network

Utility Trailer Utility Trailer From "Trade School" episode DTRS-103

Figure A

Having completed his barbecue grill, welding student Conor Tracy sets to work building a 5'x8' utility trailer, complete with a retractable loading ramp (figure A). For the trailer's critical components, he uses a flux core arc welder (FCAW) which runs hotter and penetrates deeper for a stronger weld than the MIG welder used on the grill ....

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Basic Tools:

Flux Core Arc Welder
Chop saw
Disc grinder
Plasma cutter
Center punch
Steel square, Combination Square
Clamps

• Conor refers to a computer-aided drawing of the trailer provided by his instructor for each phase of this project (figure B). The frame is composed of 2-inch square metal tubing. A tongue protrudes from the front of the frame. He measures and then cuts all the pieces on the chop saw (figure C).

Figure B

Figure C

• Next, starting with the outer pieces and working in, Conor clamps down all the cut tubing on the Platten table. He tack welds at each crossing point until the frame's shape is achieved (figure D).Then, he goes back and solid welds along each seam. Then, with his instructor's help, he flips and clamps the frame and repeats the tack/solid welding process until all the seams are connected (figure E).

Figure D

Figure E

• Aided by a forklift, Conor places a large sheet of diamond plating over the tacked frame and traces around the edges (figure F). The plating serves as the deck surface of the trailer. With the shape of the frame transferred to the plating, he cuts the shape using the plasma cutter and a clamped straight edge to guide the cutter. After tack welding the plating to the frame, he staggers 3-inch weld seams along the edge (figure G). This technique is called stitch welding. (A complete weld around the edges could cause warping and would be considered overkill.)

Figure F

Figure G

Figure H

• Using more square tubing, Conor crafts the side frames of the trailer separate from the main frame. He makes sure each post is squared to the top beam and welds the pieces together. Next, he aligns both completed side frames to the diamond plating and stitch welds each post to the main frame (figure H). He then welds the front frame between the two side frames and to the deck.

• Conor proceeds with the critical phase of the trailer: Squaring the torsion-flex axle to the frame. If the axle isn't mounted square, the trailer could potentially break apart on the road causing severe damage or even injury. Working on the bottom side of the trailer, he uses a center punch to form a divot at a centered point in the tongue.

• Next, he clamps the axle on middle section of the frame and measures the distance from both mounting brackets to the divot (figure I). Once these two measurements are exactly the same, he welds a solid seam lengthwise along the axle brackets (figure J). (Welding widthwise along the brackets could weaken the integrity of the trailer.)

Figure I

Figure J

• After attaching the wheels to the axle, Conor uses the forklift and a portable crane to flip the trailer right side up (figure K). Then, he begins forming the rear tailgate / ramp out of more square metal tubing. Before welding the ramp frame together, he drills holes through the tubing to insert a metal rod. To attach the ramp to the trailer, Conor first welds two steel mounting brackets with holes near the rear end of the main frame. He slides the metal rod through the brackets, then in through the holes in the ramp frame. Next he welds a thick metal slug on one end of the rod and secures the opposite end with a bolt that allows the gate to be removed when necessary (figure L).

Figure K

Figure L

• With the rod secured, Conor welds a fitted sheet of expanded steel mesh over the ramp frame (figure M). He also welds a latch mechanism to the railing to lock the ramp in an upright position (figure N).

Figure M

Figure N

• Next, Conor welds a hitching coupler directly onto the tongue (figure O). He also welds a drop-leg jack on the frame to keep the front-end level when not hitched to a vehicle. He mounts and wires brake lights making the trailer legal to tow (figure P).

Figure O

Figure P

• Conor finds that the factory-made fenders are too narrow to properly shield the tires. To solve the dilemma, he widens the fenders by splitting them in half and then adding a strip of 12-gauge to the middle. He welds the fenders back together, and grinds them smooth. The fenders receive and new paint job and are now the proper size. Then, he welds them to the frame allowing ample room for the tires to rotate freely, even on bumpy drives (figure Q).

• To finish the project, Conor adds a cosmetic touch to the trailer. Between each post on the railing, he welds square pieces of expanded metal, reinforcing the corners with steel gussets (figure R).

Figure Q

Figure R

School Contact Information:

Aims Community College
PO Box 69
5401 W. 20th Street
Greeley, CO 80632
Toll-Free: 800-301-5388
Website: www.aims.edu