Welder Cart

Rolling Out the Upgrade: Fabricating a Custom Multi-Tier Welder Cart

While a custom welder cart is the quintessential first project for someone learning to weld, it had lingered on my own project list for quite some time. Until now, I had been making do by wheeling my welder around on a three-tier plastic Tuffy A/V cart—a setup that more than once nearly ended in disaster when the gas cylinder tether caught and nearly dragged the bottle to the floor. It was well past time to fabricate a proper, stable cart featuring a low-slung platform for the gas cylinder and effortless mobility around the garage and shop.

I spent time iterating on a Solidworks CAD model to land on a design that balanced utility with clean aesthetics. The concept settled into a multi-tier layout:

Top tier: The welder itself, positioned at an ideal height for easy wire changes and quick access to controls.
Second tier: A dedicated spot for a tool chest sized specifically for welding consumables and tools.
Bottom tier: Open storage for additional welding-related gear.

The design also integrated side hooks for the torches and ground cable, along with a low-profile gas tray designed to accommodate a standard 7-inch diameter cylinder. This allowed the bottle to be loaded without heavy lifting, kept securely strapped in during transit, and easily removed when needed.
Here is a look at the design and fabrication process that brought it all together.

This cart involved significantly more functional design iterations than previous projects. While placing a 26-inch center-section tool chest on the second tier was already locked in, details like cable management, cylinder support, and caster selection remained up in the air. I also debated building a two-cylinder cart; since my ultimate goal was to buy a multi-process welder, having a second gas cylinder with Argon for TIG steel or MIG aluminum would be convenient. However, because I wanted the footprint to be as narrow as possible to save floor space, backward and side tipping became a serious concern when factoring in dual 150-cubic-foot (85+ lb) gas cylinders.

To evaluate the risks, I modeled the swivel casters in CAD so I could rotate them 360 degrees, setting my target tipping force at the center of the welder to 20 pounds-force. I rotated the casters to their worst-case positions, pulled dimensions from the CAD model, and ran a series of statics equations to calculate the actual tipping force based on the geometry. I tested various welder, cylinder, and accessory weights alongside different caster models. While I would have preferred a higher design force to prevent sideways tipping during transport, a 16-inch width and the overall design height limited my options. Knowing that the easy-roll casters would provide exceptionally low wheel friction mitigated some of the risk, and since I would be the sole operator, I could easily stabilize the cart when wheeling it sideways. Ultimately, I settled on a single-cylinder design with side hooks and 5-inch casters.

With most of the design finalized, I moved on to metal procurement. As per usual, I took a cut list over to my cousin's fabrication shop. For the frame, I used 1.5-inch by 1.5-inch by 0.09-inch square tubing, and the shelf plates were made from 14-gauge (nominal 0.0747-inch) sheet metal. Because the cylinder tray design wasn't completely finished yet, I decided to go ahead and start cutting and fabricating the main frame. As usual, I spec’d the cut list pieces slightly longer than necessary so I could handle my own cleanup and 45-degree mitering on the metal-cutting chop saw.

For this project, I once again used a Millermatic 211 inverter MIG welder with 0.030-inch wire, the included MDX-100 MIG gun, and C25 shielding gas. I started fabrication by welding up the square frames for the three shelf tiers. With the corner joints already mitered, I beveled each edge on an 8-inch, 1/2 hp bench grinder equipped with an 80-grit M wheel to create V-grooves for deep-penetration welds. I then deburred those edges on the same bench grinder using a carbon steel wire wheel.

One important detail to note when cutting stock for square or rectangular frames is that just because a square tube has a nominal 1.5-inch by 1.5-inch size, it rarely measures out to that exact dimension—one side might be 1.505 inches while another is 1.485 inches. For that reason, it is best to orient the tubing consistently based on its outer dimensions when cutting. This ensures easier flush grinding and a much cleaner finish after welding.

Once the joints were prepped, I fit them up tightly, checked them with a fabrication square, and measured across the frame diagonally with a tape measure to confirm squareness. I then tightened the C-clamps to keep everything level and tack-welded each corner. I followed my usual welding sequence: all four top corners, let cool; all four bottom corners, let cool; and finally, all four outer corners downhill, let cool. After removing the clamps, I finished the inside corner fillet joints. Once one frame was complete, I moved on to the next until all three were finished. Finally, I carefully ground the welds flush using an 80-grit flap disc on an angle grinder and hand-filed the corner radii with a 10-inch single-cut mill bastard file.

In my designs, I often try to mask or minimize welds for aesthetic purposes, believing it creates a much cleaner, more seamless look. To achieve a low-profile, recessed mounting method for the 14-gauge shelves rather than standard fillet welds, I devised a plug-welding scheme using quarter-inch-thick steel tabs. I cut six 1-inch by 1-inch pieces from a quarter-inch steel strip for each shelf, beveled their edges for a more refined appearance, and drilled a 3/8-inch hole through the center of each. These tabs would be offset and fillet-welded to the inside of each tier from underneath, allowing the shelf to rest on them and be secured via plug welds through the holes from the bottom. This approach results in a stylish, recess-mounted integral shelf.

To position the tabs for welding, I laid two pieces of 1.5-inch square tubing on the concrete as supports, then placed the rectangular frame on top. I stacked two tabs on top of each other inside each of the four corners—maintaining a half-inch offset from the top of the frame—and dropped the 14-gauge shelf in to center it. Finally, I measured equal distances from the frame edges to the tabs to ensure precise placement before tacking them into position.

Once all the tabs were tacked, I fillet-welded them to the frame and plug-welded the sheets to the tabs from underneath. Although I initially wanted to challenge myself by avoiding air tools on this project, I ultimately had to use an angle die grinder with a 2-inch 80-grit fiber disc to grind down the plug welds, as my standard 4.5-inch angle grinder was too large to fit into the corners. I repeated this entire process for all three tiers.

Next, I turned my attention to the caster mounts on the underside of the lowest tier. Because the tubing was hollow with a wall thickness of only 0.09 inches, tapping holes directly into it for the 5/16"-24 caster screws wasn't a viable option. Instead, I purchased 1/2-inch outer diameter low-carbon steel round tubing with a 0.12-inch wall thickness, cutting it slightly longer than the width of the frame tube to serve as weld-in sleeves that could be easily tapped. With an inner diameter of 0.26 inches—only about 0.011 inches undersized for a 75% thread on a 5/16"-24 tap—I could basically cut the threads straight out of the box. The plan was to drill slightly oversized holes in the frame and use a fillet weld around the tube for strong penetration. It seemed simple enough.

To mark the hole locations, I placed a caster at each corner and used a transfer punch. However, once I drilled the frame holes and cut the spacers to length, the process proved trickier than anticipated. Getting the sleeves positioned properly and sitting square inside the holes was a challenge. I ultimately had to use C-clamps to hold them flush while tack-welding, which carried the risk of weld spatter (even with E-Weld 4 anti-spatter spray) damaging the clamps. I originally chose this store-bought tube method only because I lacked immediate access to a lathe while still building out my workshop; had I been able to machine much thicker custom spacers with the same internal hole diameter, the method would have worked much smoother.

The next step was to grind the welded bosses flush with the underside. This process reinforced a valuable lesson I’ve learned over time—one that became clearer than ever and permanently changed my technique: when aiming for a clean, professional aesthetic, proper weld finishing and blending are absolutely crucial. Grinding down a lot of material can get tedious, but one heavy-handed pass too deep leaves a gouge in the part that requires extensive blending if you are lucky, or re-welding and regrinding if you are not.

While grinding the bosses flush, I started with an 80-grit flap disc on my angle grinder. Feeling impatient after working longer than planned, I aggressively ground several of the bosses completely flush, leaving unsightly gouges in the metal. Looking at the finished product later—and considering the high level of effort I was putting into the build—the flaws bothered me so much they kept me up at night. Since then, my approach has evolved: I start with an 80-grit flap disc, but once the weld is nearly flush, I finish it with a 120-grit fiber disc using single-direction passes, blending the material smoothly into the surrounding area. When used carefully with minimal pressure, a 120-grit fiber disc removes a minuscule amount of material—roughly 0.0001 inches per pass (I measured it with a Mitutoyo mic). While this method takes significantly more time, the final result is well worth the patience. Ultimately, I needed to re-weld around some of the spacer tubes, and I later fixed the frame by re-welding and blending the gouges.

The next step was installing the caster plates, which were pieces of quarter-inch plate serving as simple mounting extensions for the casters. I began by cutting the plates to size, rounding one corner and beveling the opposite corner on a 12-inch disc sander to fit around the fillet welds in the corners of the frame. Next, I beveled the plate edges on the bench grinder so I could weld them and grind everything flush. With the prep work done, I placed a caster in position, held the plate underneath it, aligned the existing three mounting holes, and traced the final hole location with a pencil. I then punched the hole center on the plate with a prick punch followed by a center punch, pilot-drilled it with a hand drill using a 7/64-inch 135-degree bit for easy alignment, and finished drilling it out on the drill press. I repeated this process for each plate.

With the holes complete, I clamped a scrap piece of quarter-inch plate to the bottom of the frame and used a second clamp to secure the caster plate flush against the frame surface. From there, I tack-welded two corners of the plate. I repeated this entire process for each of the remaining caster plates.

After fully welding the caster plates into place, I took the opportunity to fix the gouges I had unintentionally created earlier and touch up the tube edges that lacked full penetration. I started by cleaning all the welds with a 3-inch carbon steel wire wheel on a hand drill to strip away surface oxides. Then, I welded up the gouges and applied my updated blending technique—starting with an 80-grit flap disc, finishing with a 120-grit fiber disc on the angle grinder, and feathering the repairs smoothly into the surrounding frame. Once that was done, I hand-tapped the 5/16"-24 threads using a tapping block.

Although the upper left corner of the frame still required some minor cleanup around the tubes, the image shows the vastly improved results following the repair.

With the lower and middle tiers finished, I turned my attention to the handle on the top frame. My goal was a round handle that blended seamlessly into the upper frame. To achieve this, I purchased a piece of 1-inch nominal black pipe, stripped off its outer coating using a CGW red stripping disc on the angle grinder, cut it to length on the chop saw, and squared the ends on the disc sander.

Next, I fabricated the mitered ends for the handle. I welded a square piece of 1/8-inch steel onto the ends of two pieces of 1.5-inch square tubing—making them long enough to securely clamp in the chop saw vise—then ground down the welds and rounded the corners with a hand file. To create as flush a match as possible between the pipe and the corner pieces, I used a CNC mill I had access to in order to square up the welded faces that would mate with the pipe. Back in the garage, I made the final miter cuts on the corner pieces to the required length.

I debated for a while on the best method for welding the tube, ultimately deciding to plug-weld it from the inside through the milled face to the edges of the pipe, keeping the weld completely invisible. To pull this off, I centered the pipe on the face of the milled miter piece and traced its outline. I then used a 3/8-inch drill to punch three access holes through the face, positioned so they lined up with the pipe edges without extending past its outer diameter.

Next, I set up a rigid jig using large C-clamps and shims to perfectly align the pipe with the mitered piece. With everything locked firmly in place, I completed the welds by plug-welding through the access holes from the inside.

With the left side complete, I moved on to the right side, orienting and drilling the plug-weld holes. I set up the makeshift jig in the same manner and plug-welded the holes. The final result, shown in the image, turned out impressive.

Once the handle assembly was fully welded, the next step was attaching it to the top frame. This process was relatively straightforward: I used the same C-clamp method I relied on earlier to bring the pieces into alignment and plane, then welded the tops, bottoms, outside corners, and finally the inner fillets, allowing the welds to fully cool between each step. With the welds completed, I finish-ground and hand-filed the radii to match the rest of the frame.

The next step was to fabricate mounting tabs for the cylinder straps. To make swapping cylinders quick and painless, the design featured a rear platform where the tank sits, secured by nylon cinching straps with squeeze-release buckles, similar to those found on a backpack.

To accommodate the straps, I fabricated a total of four slotted tabs out of 1” x 1/4” steel strip (two per strap). Since I didn’t have access to a mill to machine the slots, I marked the center points for the two end radii about 1.25” apart and drilled them out on the drill press. Next, I used a Dremel with a fiber-reinforced cut-off disc to clear the material between the holes, then hand-filed the edges to create a clean, finished slot shape. Finally, I fillet-welded the tabs in place at the top-rear of the middle shelf frame and the underside of the top shelf frame.

With the tabs welded and cleaned up, it was time to assemble and weld the uprights, starting with the bottom tier.

To ensure precise alignment with the frame corners, I clamped 1/4” steel flat strips to the uprights to create an artificial registration edge, allowing the frame and upright surfaces to sit flush. After tack-welding the uprights to the frame, I verified perpendicularity using a fabrication square. I repeated this process for each leg before moving on to the middle tier. Once everything was fully tacked and square, I finished by welding all of the outside butt joints.

With the middle tier welded in place, I repeated the process for the top tier. Due to minor stack-up tolerances, the top frame didn't sit perfectly flush at first; however, a short ¾” Pony pipe clamp easily pulled the assembly into proper alignment for tack welding.

With tack welding complete, I proceeded to fully weld all outside butt joints and upright fillet welds.

Next up was weld blending and finishing. I followed my standard multi-step procedure: oxide removal with a 3” carbon steel wire wheel on a hand drill, initial weld knock-down using an 80-grit flap disc on a 4-1/2” angle grinder, finish-feathering with a 120-grit fiber disc, and final corner rounding with a hand-file. While tedious, this meticulous process gives results that speak for themselves.

Beyond refining my technique, this build taught me a valuable shop management lesson: I no longer grind inside the garage. Despite protective sheeting and barriers, fine grinding dust inevitably coats every surface, making cleanup a nightmare. While an overhead air filtration system is on my future project list, setting up a tarp outside for cutting and grinding makes managing chips and dust infinitely easier and keeps the workspace clean.

With the basic frame complete, I bolted on the casters and rolled it out for a test run. The cart rolled smoothly and effortlessly like it was gliding on ice.

Next up were the custom hose and ground cable hooks, constructed from 1” x 1/8” steel flat bar and 1” OD x 1/8” wall carbon steel tubing. To determine the correct dimensions, I measured the welding gun hose diameter, estimated the ideal loop configuration for a clean layout, and modeled the design in CAD to verify frame clearance. After cutting the flat bar, I bent one end 90 degrees in the bench vise to be fillet-welded to the inside of the upper frame. I then radiused the mating ends of the strips to match the contour of the tubing, beveled the joining edges, and welded them together. Finally, I hand-filed the strip-to-tube interfaces for a seamless transition and radiused the front edges of the strip to prevent chafing or damage to the hose.

With the hooks complete, I plug welded the top shelf in place and ground the welds from underneath using the angle die grinder.

The final welded assembly was the cylinder tray. After several CAD iterations, I settled on a design balancing two key constraints: minimizing the lift height for a heavy 150 CF cylinder to just an inch or two while maintaining a 1” ground clearance to prevent dragging on uneven floors. I also needed a functional wear surface that would allow sliding the tank on and off without scratching the powder coat (more on that solution later). Ultimately, I designed a round tray featuring a half-round front plate mounted at that 1” clearance height.

Back at the fab shop, my cousin cut the 1/4” thick round base on his CNC plasma table. Forming the front plate proved tricky; we initially tried bending a flat strip around a large welding cylinder, but the resulting radius wasn't smooth enough. Fortunately, we found a short length of large-diameter pipe that matched the exact diameter we needed. My cousin split it in half on the bandsaw, and I used a curved pipe section directly in place of a bent strip.

To ensure a clean joint, I beveled the lower edge of the pipe section before welding it to the base disc. Afterward, I ground down the weld and hand-filed the perimeter smooth. Interestingly, the plasma cut settings or torch alignment had naturally put a slight bevel around the edge of the base disc; I turned this minor quirk to my advantage by hand-filing it uniform all the way around, creating a crisp, deliberate aesthetic detail.

To attach the tray to the welder cart, I used two pieces of 1.5” x 1.5” x 1/8” angle iron. With the wheels installed, I flipped the cart upright to verify frame ground clearance and determine the proper support length. Next, I marked the center of the tray's front plate, placed the tray on a flat reference surface, shimmed the angle iron ends so they would be slightly recessed, oriented them equidistant from the centerline, and tack-welded them to the tray.

With the supports tacked, I flipped the cart upside down, removed the wheels, and marked the cart's centerline to properly align the tray assembly. After holding the tray in position, I tacked it to the cart frame. Once I verified squareness and made minor adjustments, I fully fillet-welded the angle iron to the cart and completed the remaining seams on the tray.

To protect the powder coat from direct cylinder impact and abrasion, I fabricated a wear disc from 1/8” thick recycled UHMW polyethylene, securing it to the top of the tray with countersunk #10-24 flathead screws. UHMW offers exceptional wear resistance and a very low coefficient of friction, allowing a heavy tank to be easily tipped and slid onto the platform without lifting. To install it, I located and center-punched three evenly spaced mounting holes, drilled them with a hand drill, and hand-tapped the threads using a tapping block. The image shows sacrificial screws used to protect the threads during powder coating.

Fabricating the wear disc required a bit of ingenuity, but UHMW machines cleanly and easily. To test the process, I ordered a 12” x 12” x 1/8” square of UHMW and a Bosch 1/4” carbide 2-flute O-flute router bit. After clamping down the material, I made a few test cuts in the corners using my cordless router, which yielded very clean edges.

To achieve the precise diameter needed, I measured the offset distance from the router base's edge to the cutting edge of the bit. Subtracting this offset from my target disc radius gave me the exact radius required for a circular routing template. I ordered an aluminum disc of the correct size to act as a guide, clamped it to the center of the UHMW sheet, and routed around it while keeping the router base firmly in contact with the template at all times. The result was a perfectly round UHMW disc of the exact required size. To finish, I clamped the disc to the cylinder tray, marked the mounting holes using a transfer punch, and drilled and countersunk them.

My powder-coater typically plugs all threaded holes with screws and critical through-holes with rubber plugs to prevent powder from curing inside the threads, which otherwise makes re-tapping them later a requirement. To save on coating costs and shop time, he suggested I plug the holes myself. Following his advice, I prepped the cart by threading inexpensive grade 2 hardware into every threaded hole. With that done, the cart was fully prepped and ready for powder coat.

For this project, I wanted to see if the round handle and the uprights could be powder-coated in two distinct colors. After discussing it with my coater, I learned it was entirely feasible: they use high-heat Kapton-style tape and aluminum foil to mask the transition areas. The first color is applied and cured in the oven, and the process is repeated for the second color. I chose Prismatic Powders' Bengal Silver for the uprights and gloss black for the rest of the frame. The coater did an exceptional job and sent over a few preview pictures of the process.

With the powder-coated cart back in the garage, I reinstalled the wheels and mounted the UHMW wear disc to the tray. To further protect the finish, I riveted two additional UHMW strips to the rear of the frame at the middle and top tiers using steel rivets. These strips act as a non-marring cushion for the gas cylinder to rest against, preventing any scratching or abrasion from tank movement during transport.

For the middle storage tier, I originally planned to use a 26” Craftsman intermediate black tool chest, but that model was discontinued. While I would have preferred a higher-quality unit, I settled on a Workington 3-drawer chest from Amazon that matched the required dimensions and aesthetic. To finish the interior, I lined the drawers with protective non-slip toolbox liners.

One important takeaway regarding powder coat is that it is not impervious to damage. While some formulations offer better abrasion resistance than others, powder coat is ultimately a plastic layer, and gloss or dark finishes tend to show blemishes much more easily. In a workshop environment filled with grinding dust and debris, it is always best to clear surfaces using compressed air rather than wiping them down with a rag, as trapped grinding dust can act as an abrasive and scratch the finish.

Here is the completed welder cart fully loaded, equipped, and ready for active shop use.

​Rolling Out the Upgrade: Fabricating a Custom Multi-Tier Welder Cart

Rolling Out the Upgrade: Fabricating a Custom Multi-Tier Welder Cart