A lot of metalwork never makes it to the shop. It happens in alleys and plants, on gravel shoulders and behind grocery stores where a loading dock hinge tore loose under a pallet jack. Mobile welding is the answer when the weld has to meet the work, not the other way around. Done properly, a mobile rig delivers structural repairs, stainless steel welding, aluminum welding, and precise TIG or MIG work with the same quality you expect in a controlled bay. The constraints are different out in the field, but the mindset is the same: control variables, prepare clean base metal, and verify the result.
I run a truck welding setup that has seen a little bit of everything. A wrought iron fencing rebuild after a box truck kissed a corner post. A fast fix on a crusher guard at a quarry with fines blowing like snow. A cracked aluminum ramp on a refrigerated trailer that needed to be back on the road before nightfall. Different materials and environments, one rule: the job has to hold up when the welder leaves.
Mobile welder is more than a title on the door. It’s an equipment strategy, a power plan, and a way of staging consumables so that you can solve problems without a warehouse at your back. On site welding services will always be constrained by unknowns. You can’t predict where the nearest outlet is or whether the wind will gust just as you strike an arc. You prepare for that.
A proper portable welder rig balances weight and power. It needs to carry a reliable generator, a welder that can run stick and MIG, sometimes TIG, oxy-fuel for cutting, a small press or porta-power for straightening, grinders, clamps, and a surprising number of wire wheels. I see rigs that look like they could lay pipe across Alaska, but they struggle with a simple disturbance in shielding gas. It’s not about the fanciest machine. It’s about the right machine, maintained, with redundancy where it counts.
MIG dominates mobile work because it’s fast and forgiving in production conditions. With solid wire and gas, it’s clean and efficient indoors. With flux-core, it tolerates a drafty alley or a breezy rail yard. That said, I keep stick rods and a TIG torch on the truck. Structural tacks high on a mezzanine often go faster with 7018 and a short lead than dragging a MIG whip up a ladder. Stainless steel welding in a food plant or sanitary pipe repair usually pushes you toward TIG to control heat input, color, and cleanliness. Aluminum welding can go MIG or TIG depending on thickness, joint type, and access. A mobile welder is not married to a single process. You pick the method that fits the metal and the conditions.
The generator is the heart. I prefer an engine-driven welder-generator with at least 10 kW continuous output, more if you run multiple grinders or a plasma cutter. It should comfortably power a 200 to 300 amp MIG job while keeping lights and fans running. If you work heavy equipment and structural steel, size up. Think about duty cycle. A nameplate rating at 25 percent duty does not tell you what happens when you’re on your third consecutive pass on a 3/8 inch flange. You don’t want thermal shutdown sixteen minutes before a rainstorm.
Gas management makes or breaks MIG and TIG away from the shop. I carry separate cylinders for C25, pure argon, and a tri-mix for stainless, plus flux-core wire as a backup when the wind refuses to cooperate. I keep spare regulators and short hoses ready because a cracked O-ring can turn a profitable afternoon into hand-wringing. If you weld aluminum MIG with a spool gun, argon consumption surprises people who only run short beads in a booth. Plan cylinder size to your typical day. A 125 cubic foot bottle goes faster than you think at higher flow rates.
Over the years I’ve learned to stash a wind screen in the truck. It’s nothing fancy, just a foldable panel that lets me shield a joint on a fence or a gate hinge without burning through gas. It also keeps passersby from staring directly into the arc on a sidewalk job. Safety for them and less arc flash for me.
When you fix an industrial handrail that’s been hit by a pallet, MIG welding lets you prep, fit, and lay down consistent fillets quickly. For mild steel, C25 shielding gas with ER70S-6 wire handles dirty mill scale better than a bare filler. On galvanized, strip the zinc in your weld zone, grind back to bright steel, and keep fume control in mind. Outdoors where wind is steady, flux-core wire like E71T-11 or gas-shielded E71T-1 solves porosity trouble when pure gas would blow away. I have a simple test: if my hood lens shows the arc blowing like a comet tail, switch the process or change the angle before you chase pinholes for an hour.
Tentative measurements matter. Many mobile calls revolve around material that’s thicker than it looks. A cast steel coupler or a trailer tongue might hide a quarter inch of base metal under paint and grime. I bring a caliper and a magnet, scratch a clean line, and read the edge. If the part is structural, I set parameters for full penetration or use a root pass with a slight weave, then step up to fill and cap. It’s tempting to lay a fat bead as a bandage, but fat beads do not equal strength when the root is cold.
I treat the truck like a traveling shop, built around the kind of calls I get. For wrought iron fencing, gates, and railings, I keep a small selection of forged leaves, collars, and standard pickets so I can match patterns on the spot. Nothing makes a client happier than seeing a damaged gate repaired without waiting for special order components. For aluminum ramps and dock plates, I stock 5356 wire for strength and color match with many alloys. Stainless jobs get ER308L or ER316L based on environment. If it’s close to salt or de-icer, I default to 316 for corrosion resistance.
Clamps matter more than people admit. Half my rig is fixturing. Deep throat C-clamps, a couple of locking pliers with swivel pads, two strong magnets with switches so they release under load, and a handful of wedges. On a truck frame repair or a pipe repair in a tight trench, getting a joint aligned and held is most of the job. The weld itself goes quick once the root lands where it should.
I keep a log of wire and consumables usage by job type. After a year, patterns appear. For example, fence welding eats cutoff wheels, not wire, because prep consumes more time than weld. Heavy equipment repairs burn rods and gouging electrodes when you need to excavate a crack in a bucket ear or loader arm. That data guides what I buy in bulk and what I keep light.
Mobile work puts you under pressure to finish fast. That can lead to shortcuts. The thing that keeps me in business is saying no to bandages when the part is structural. A cracked bracket on a spreader bar looks small, but if it holds a hoist chain, the liability is massive. I’ll refuse a surface weld and insist on removing and plating both sides, or fabricating a new bracket out of proper material. That’s not being difficult. It’s being a certified welder who likes to sleep at night.
AWS codes and procedures exist for a reason. Not every job requires a formal WPS in a binder, but the principles still guide field decisions. On structural steel, I lean on D1.1 practices for joint prep and preheat. On stainless in sanitary service, I follow D18 cleanliness standards where practical, especially when TIG welding inside a plant. If a client asks for paperwork, I can provide it, including PQRs and welder continuity if we are doing code work. Even when no one asks, the habits carry over: measure, preheat when required, control interpass temperature, avoid weaving on certain materials, and record heat input when it matters.
Every material carries its own field quirks.
Mild steel on site is forgiving, but it hides contamination. Paint, oils, zinc dust, and wet rust all create porosity. My default is to grind a clean groove, wipe with acetone or a degreaser, then preheat lightly if the material is thick or the air is cold. In winter, a small propane torch can make the difference between a glassy weld and a brittle one. I use a temperature stick to check preheat when the base is over a quarter inch.
Stainless punishes contamination and too much heat. If I’m repairing a stainless handrail, I isolate carbon steel tools and wire brushes. I use a dedicated stainless brush. After TIG welding, I passivate with a gel pickling agent or a citric acid cleaner when the site allows it. Discoloration isn’t just cosmetic. Those straw and blue colors mark oxide formation that can invite corrosion. An extra ten minutes cleaning protects a reputation. If the environment is sensitive, for example inside food processing, I set up a plastic containment to catch dust and run a HEPA vacuum on grinders.
Aluminum moves. A cracked trailer ramp or a cast aluminum pump housing requires bracing before you tack. If you weld without restraining, the part will pull and reward you with a misaligned hinge or a crooked seal face. I’ll drill stop-holes at the end of a crack to blunt it. On castings, I burn off oils with a gentle preheat, then wire brush with stainless before and between passes. Porosity loves trapped oil. Sometimes the fix requires short beads with peening to bring bubbles to the surface before a cover pass.
Pipe welding in the field depends on the medium. A simple water line repair can be MIG-tacked and stick welded quickly if you have isolation valves and can dry the line. Any line that carried hydrocarbons or chemicals demands a different approach. Purge, test, and follow site safety. For thin stainless tube, TIG with an argon purge produces a sanitary root that won’t trap product. I carry purge dams and tape for that reason.
Mobile welding is as much logistics as it is arc time. I build each day around route and access. If a job sits behind a grocery store, ask about delivery schedules. That loading dock might be jammed with trucks between 6 a.m. and noon. If a fence repair borders a neighbor’s yard, expect a locked gate, sprinklers, curious dogs, and little kids. Bring cones, barricade tape, and a spotter when grinding near pedestrian areas. It’s not a police scene. It’s common sense.
When I get a call for a cracked hinge on a commercial gate, the client asks, how fast can you be here. If it’s a true emergency welder situation, I stop what I’m doing and roll. Most “emergencies” are really urgent inconveniences, but sometimes they’re critical. A broken railing at a hospital entrance needs attention now. I keep a small reserve of time in the schedule for that.
Job documentation keeps the chaos in check. I snap photos before and after, measure the work, note materials, and mark heat numbers when using structural shapes. Not because anyone is auditing me every time, but because, when they do, I have it. Also, if a gate sags again six months later, I can see exactly what we did and whether the post moved or the hinge leaf fatigued.
Field welding mixes hot metal, open public spaces, fuel, and electricity. That cocktail deserves respect. I run a fire watch after grinding or cutting near dry brush or wooden pallets. Five minutes sweeping and misting beats a fire department call. I position the truck for egress, not just convenience, so if a forklift loses its brakes I’m not trapped against a bollard. PPE goes beyond a hood. Ear plugs fight tinnitus when you’re under a metal dock where sound reflects. A respirator matters when welding galvanized, even outdoors.
On client sites, safety rules can be strict or vague. I bring what the strict sites require as a baseline: harness and lanyard for aerial lifts, a hard hat, safety glasses with side shields, steel toe boots, and hi-vis. The result is I never have to leave a job to find gear. It also signals professionalism to the foreman deciding who gets the next purchase order.
Many shop owners ask what to charge for on site welding services. It depends on your region, but the principles travel. You charge for travel time, your base rate for welding, and a premium for emergency response when you’re turning away scheduled work. My own range floats with fuel prices and distance. Heavy equipment repair with a lot of grinding and gouging demands higher rates than simple fence picket replacement, because consumable burn rate and skill demands are higher.
Clients sometimes compare a mobile quote to a shop quote. Apples and oranges. A shop job assumes ideal conditions and efficient staging. A field job absorbs all the context switching and setup. I try to make that clear ahead of time, and I offer options. For a gate, I might quote a quick, on-site hinge rebuild or a more durable approach: pull the gate, fixture in the shop, replace hinge barrels, reinstall, and align. The second option costs more and takes longer, but it lasts. If the client chooses the quick fix for budget reasons, I set expectations in writing.
A distribution center called about a torn dock plate where forklifts transition into trailers. The hinge rib welds had cracked in three places. The base steel was 3/8 inch, heavily worn. I blocked the plate, cleaned back to bright metal with a flap disc, and found the original welds were cold. I beveled to a 60 degree groove, preheated to about 200 F with a propane torch, and ran multiple passes with E71T-1 flux-core at about 250 amps due to steady wind. Between passes, I kept interpass temperature warm but not hot enough to warp the hinge. I added a 3/16 inch backing plate under the rib at the worst section. The plate went back into service within an hour of cooling. A week later, they asked me to upgrade the remaining docks before failure, which is always the better way.

On a wrought iron fence that had taken a hit from a municipal mower, the corner post leaned and three pickets were bent. I excavated next to the post to see whether it was set in concrete. It was, but the concrete had fractured. I cut the post clean, chipped the top of the footing, and installed a new post with a sleeve anchored to the reworked footing. The finish welds were MIG with C25, stitched to control heat. I kept the flames and blending minimal to preserve the old paint texture, then touched up with a rust-inhibiting primer. The neighbor never noticed a repair occurred, which is the goal for residential fencing.
A contractor called on a Saturday about a cracked aluminum ladder rack on a work truck. It had been repaired twice, each time welded directly over the old cracked joint. No surprise it cracked again within inches. I ground out the old area, added a gusset on the tension side of the joint, and welded using a spool gun with 5356 wire. I kept bead lengths short, brushed between passes, and let it cool naturally. That rack has stayed together through two winters because the load path finally made sense.
Process choice balances quality, speed, and conditions.
MIG is ideal for mild steel fabrication and repair where wind can be controlled or flux-core can stand in. A mobile welder can fit and finish a gate, rack, or bracket quickly with MIG, and the arc stability helps where access is awkward. The trade-off is sensitivity to wind and surface condition. Dirty metal or a gusty lot makes porosity a real risk.
TIG shines on stainless and thin aluminum where appearance and control matter. For railings inside an office lobby or an exposed stainless handrail, TIG produces a clean bead and controlled heat tint. The cost is time. Setting up, purging, and welding TIG outdoors is slower, and you have to guard your gas even more than MIG. It’s often worth it for critical stainless or precision work.
Stick is the field bulldog. It runs in wind, it tolerates dirt better, and with the right rods you can tackle structural connections and heavy equipment. E7018 on properly cleaned and prepared joints produces strong, ductile welds. It does leave slag and requires more finesse for thin materials. I use stick for structural tie-ins where a short lead and a simple machine beat dragging a MIG gun 120 feet up a stair tower.
There’s a difference between welding a gate hinge and welding a frame connection on a mezzanine. The latter calls for a certified welder under AWS codes, with procedure qualification and, often, inspection. Structural repairs need documentation for engineers and insurers. If a job involves structural steel, ask who the engineer of record is and what procedures are required. Many times the answer is none, just fix it, which is a red flag. On those jobs, I either bring in an engineer to bless the repair, or I limit the scope to non-structural tasks. A smart mobile welder knows which calls to accept and which to reroute.
Summer jobs often fight heat and glare. Shade the area when possible to see the puddle. Hydration seems like a throwaway tip until you’re holding a 400 degree part and the wind stops. In winter, batteries die, steel turns brittle, and your breath becomes a source of condensation in a joint. Preheat becomes essential on thicker sections. Keep rods warm in a rod oven or a small heated box. I learned that the hard way on a cold November morning chasing low hydrogen performance while my 7018s soaked up moisture in the open air.
Rain and snow change access. Store a tarp and some light framework to make a quick shelter. It’s not about staying dry for comfort. It’s about keeping the work clean and keeping electrical connections safe. A wet cord on a pitted lot is how you ride home with a tingle.
Not every repair should return the part to its original state. Some designs failed because they were marginal on day one. If a gate drops every spring when the frost heaves, a taller hinge with a grease zerk outlasts a fragile barrel. On a trailer, replacing a thin stamped bracket with a properly gusseted plate spreads loads and saves the frame from tearing. On a loading dock, adding a small wear pad where a forklift tire scuffs protects the main structure.
I keep a mental library of such upgrades, and I propose them when appropriate. They cost a little more upfront and save a lot later. Clients appreciate options that reduce downtime, and it sets you apart from a welder who just runs beads where the crack used to be.
Most clients don’t weld, and they shouldn’t have to. A little context helps them get better results. When you call, describe the material, size, and environment. Tell me if the piece can be moved, even a few feet, or if it’s fixed. Share photos with a tape measure in the frame. If the work is on a public sidewalk or street, expect us to set up cones and screens for safety. If it’s inside an industrial site, have the permit process ready so we’re not waiting at the gate while sparks should be flying.
Emergency welder requests come with a premium because they interrupt scheduled work and often require after-hours labor. If the issue is a fence gate that doesn’t latch, and a quick temporary tie-back will secure it, say so. We can schedule a proper repair at a lower rate and do it right.
The best compliment a mobile welder can hear is that the work looks like it came out of a shop. Achieving that on a sidewalk or beside a muddy trench requires discipline. Prep like you’re inside. Protect your gas, your puddle, and your eyes from wind and glare. Choose the process that suits the material and the moment, whether that’s MIG for speed, TIG for finesse, or stick for rugged reliability. Keep AWS practices in your pocket even when no one is watching. And build your rig so that when the call comes for heavy equipment, wrought iron fencing, gates, railings, or a structural repair, you have the equipment and judgment to say yes with confidence.
Mobile welding is not a lesser version of shop work. It’s metalwork that meets real-world constraints head-on. Done well, it keeps trucks rolling, docks open, fences secure, and the quiet infrastructure of a city intact. The welds don’t care whether they were laid under skylights or under a January sky. They care that the metal was clean, the parameters were right, and the welder respected the job.
On Call Mobile Welding
917 J Pl Suite 2, Plano, TX 75074
(469) 750-3803