An Improved Gas Cylinder Clamping System
by Ralph Waters

I recently decided to treat myself to a capable MIG welder, and purchased a Lincoln Power MIG (see compact wire feeder/welders). I decided to build my own shielding gas bottle platform at the rear of the machine that would allow me to accommodate small CO₂ gas bottles, and add a handle to aid in moving the unit around the shop.

My clamping system consists of two components:

(1)	a more positive cylinder clamp that would keep the cylinder from rattling around, and
(2)	an adapter to support my CO2 bottle, which is considerably smaller than a compressed gas bottle because its contents are liquefied.

PART 1 - The main clamp consists of an inverted "U" which rotates at the base and presses the cylinder firmly into the factory stabilizers with two small feet. A turnbuckle on each side adjusts the clamping force and will accommodate any size cylinder. One side benefit of the round tube handle is that the welder can now be maneuvered just like a shopping cart, and the power cable coils neatly around it for storage.

When the turnbuckles are unhooked from the eye bolts, the assembly pivots down to ground level so that loading a fresh cylinder is a simple matter. A variation on this design could be to mount the bracket legs on the outside of the welder chassis instead of the inside, using longer tabs to allow the legs to lie flat on the ground, making a large gas cylinder easier to load.

The dimensions shown are "as built" for my welder (from scrap, of course) and may have to be modified to fit yours. The one piece of round tubing makes a comfortable handle, and the square tubing everywhere else simplifies alignment during fabrication. The tabs at the base of the vertical legs were drilled to accommodate the bolts used to mount the OEM cylinder tray. Be sure to check the full range of motion on the handle before drilling & welding these tabs, so that the handle touches the ground before the arms contact the lip of the cylinder support tray. It's best to mount the cylinder support legs last so they will fit your cylinder perfectly, and maintain a little gap between the cylinder and tubular handle. Don't do any welding near that cylinder!

List of Material for Clamp
Qty	Material	Length	Usage
1	1-3/8" Round Steel Tube, .062" wall	14"	Horizontal Handle
2	1-1/4" Square Steel Tube, .080" wall	24"	Vertical Arm
2	2" x 1/8" Flat Hot-Rolled Steel Bar	2-1/2"	Mounting Tab
2	2" x 1/8" Flat Hot-Rolled Steel Bar	1-1/2"	Cylinder Foot
2	3/4" Square Steel Tube, 0.080" wall	3-1/2"	Cylinder Leg
2	5/16" Eye bolt w/ 2 flat washers + 2 nuts ea.	3"	Arm connector
2	5/16" U-bolt w/ 4 flat washers + 4 nuts ea.	2"	Bracket connector
2	1/4" Turnbuckle	4-7"	Clamp Adjuster
2	Nuts to fit OEM tray mounting screws		Main Mounts

PART 2 - I'll be the first to admit that the adapter to support my choice of CO₂ bottle appears "unrefined" (to say the least), but it is simple to make and has served me well for several years now. My only regret is that no welding is required.

A wooden 2x4 is placed on top of the welder's lower stabilizer bracket, elevating the bottle so that its shoulder now extends above the welder's upper cylinder stabilizer bracket, and the valve is at a convenient height for use. The sheet aluminum is formed to the curvature of the cylinder, then sheared on each side to create two tabs which are bent parallel to each other and screwed to the 2x4. In place, the aluminum skirt then cups the base of the cylinder, extending well beyond the edge of the lower stabilizer bracket, and the 2x4 is roughly centered under the bottle. The weight of the cylinder and the vertical tubes of the new clamp (above) keep the 2x4 and cylinder exactly in place, held securely against both the upper and lower stabilizer brackets

List of Material for Clamp
Qty	Material	Length	Usage
1	2x4 Douglas Fir	13"	Support beam
1	Aluminum Sheet 6061-T0, .062 Thick	12" x 12"	Extension skirt
2	#10 x 1" Self-Tapping Cap Screws

When both components are in use together, a 20 lb. CO₂ cylinder is held securely.