Custom Gates and Railings Fabricated On Site with TIG and MIG

Walk around any well-kept property and the metalwork tells a story. Gates that swing square without scraping the latch post. Railings that feel solid under a winter glove. Welds that look like they belong, not like a patch on a patch. Those details come from a welder who can read both the metal and the jobsite, then choose the right process, TIG or MIG, to deliver a clean, structural result. When fabrication happens on site, the work meets the real geometry, the actual slope, the way the hinge line lines up with the grade. That is where custom gates and railings stop being a catalog item and start becoming part of the place.

I have fit gates in alleys with two inches of forgiveness on one side and a brick pilaster that ran out of square by nearly an inch. I have reworked stainless guardrails on a loading dock after a forklift clipped a post. The principles do not change. Good prep, correct filler, solid power and gas management, and a welder who will not accept a hinge that binds in cold weather.

Why on-site fabrication solves problems shop builds can’t

Off-site fabrication has its place. You control temperature, wind, humidity, and power. Jigs hold parts square, spatter shields keep finishes clean. Then you get to the property and realize the concrete is out by half a bubble, the block wall bows, or the fence line dips before the neighbor’s yard. Shims can only hide so much. A mobile welder with a portable welder on a truck or trailer can field-fit, tack, check swing, and fully weld after verifying clearance. That is the difference between a gate that slams once and one that closes smoothly for 15 years.

On site, you also manage real structural loads. A driveway gate hung on a steel post anchored near underground utilities needs different base plates and anchor spacing than the same gate attached to a poured wall. A railing at an industrial facility takes repeated side loads from carts and equipment. If a post flexes, it is not just a cosmetic issue. Adjusting the post embedment, plate size, and weld sizing in the field keeps the installation honest.

MIG and TIG in the field, and why both matter

TIG and MIG are not interchangeable hammers. They overlap, but each shines under specific conditions.

MIG is the workhorse for carbon steel fencing, wrought iron fencing elements, and structural gate frames. With solid wire and gas, it is fast, consistent, and repeatable. In wind or where gas coverage is compromised, flux-core MIG keeps the puddle protected and allows hot passes that tie in deep. For long runs on railings or when joining thick to thin sections, MIG controls heat input well enough to avoid burning the light sections while still achieving fusion on heavier members. MIG also excels at tack timing, especially when you need to test swing, snap a tack, close, check, then stitch for strength.

TIG is the scalpel. When I’m mating a stainless top rail to a polishing-ready post, TIG gives me a narrow heat-affected zone and precise bead profile. The same goes for aluminum gates where cleanliness and controlled heat are everything. With the right cup, gas lens, and amperage control at the torch, TIG creates welds that nearly disappear after a light pass with Scotch-Brite. On a coastal property or around food processing equipment, stainless steel welding with TIG is the standard. For delicate scrolls, collar details, or when matching existing architectural ironwork, TIG lets you place metal exactly where it needs to go without flooding a tight joint.

The choice often comes down to environment, base metal, joint fit-up, and required finish. Good mobile welders arrive ready for both: a dual-bottle rack, a spool gun for aluminum welding, a dedicated TIG machine with high-frequency start, and a MIG setup that can switch from solid wire with C25 gas to flux-core when the wind picks up.

Materials that behave differently under a torch

Steel forgives a lot if you prep it well. Remove mill scale, open the root for full penetration on structural joints, and control heat so you do not pull a frame out of square. For gates and railings, I tend to spec mild steel tube for the main frame, with solid bar or preformed pickets to match design. MIG stitches up those joints quickly, then TIG blends accent pieces where you want tight beads.

Stainless asks for discipline. Separate grinding wheels, dedicated stainless brushes, clean gloves. Cross contamination shows up when a beautiful railing bleeds rust stains a month later. For 304 stainless in a residential setting, a TIG weld with ER308L filler gives a clean finish. In a harsher industrial environment, 316 with ER316L filler holds up better, especially around chlorides. Heat tint is not just about looks, it can reduce corrosion resistance, so I protect with a larger cup, slow travel, and sometimes a post-weld passivation gel. For stainless handrails in a lobby, the final polish to a uniform grain so the weld blends into the run is part of the job, not an extra.

Aluminum rewards preparation. Degrease, then stainless brush the oxide layer just before welding. If a gate frame needs to stay light, 6061 tube is a common choice, paired with ER5356 filler for strength and color match after anodizing. Heat management is critical. Preheat on heavier sections prevents cold starts and porosity. With a spool gun, MIG can be efficient for aluminum rail panels, but when the fit-up is tight and the finish visible, TIG rules. Be mindful when combining aluminum with steel posts, as galvanic corrosion becomes an issue. I plan an isolation layer at connections, and fasteners that will not set up a battery in wet conditions.

Structural accuracy in the real world

A gate built square in the shop will not save you if your hinge post leans a degree out of plumb. Out in the field, I build from the hinge line. Set the post true, then pull a string line and hang the frame on temporary pins. Tack the frame, cycle it five or six times, and measure the gap at mid swing and closed. If I see drift, I identify where the heat is pulling and sequence the welds to counter it. Sometimes that means TIG tacks at corners before committing to MIG fillets, sometimes it means alternating sides in short increments and letting the metal cool between beads.

Railings demand attention to code and comfort. For residential stairs, the rise and run vary in the real world, especially in older homes. I cut and tack on site so the handrail follows the stair line, not an average of riser heights. At commercial sites or an industrial loading dock, I verify load requirements for guardrails and toe boards, and I lay out post spacing so the midrails stay within code. When you weld posts to a base plate, oversize the holes to allow minor adjustments during install, then grout for full bearing under the plate rather than relying on bolt tension alone.

On pipe runs and pipe welding repairs that tie into gates or protective barriers around equipment, alignment is unforgiving. Even small misalignments transmit stress. For pipe repair near fence lines or curb rails, I prefer fit-up clamps, spring levels, and short alignment tacks that can be dressed easily before running a root pass. I treat any public-facing weld as both structural and visible.

Finishes that last, not just look good on day one

Paint hides sins until weather peels back the truth. I start with clean steel. Degrease, remove scale, then prime. For wrought iron fencing, an epoxy primer under a urethane top coat holds up to sun and snow. Powder coat looks great and resists chips, but it locks in whatever surface you deliver. If I know powder coat is coming, I aim for welds that need minimal filler or sanding.

On stainless, blending is everything. The surrounding grain direction guides the final passes. With a 180 grit belt, then Scotch-Brite, you can erase the bead outline if you controlled heat. Heat tint gets treated. There are field-safe passivation gels that neutralize and restore the chromium-rich surface. For aluminum, a uniform mechanical finish often beats a mirror polish, especially outside where glare and fingerprints show up immediately. If anodizing is planned, matching filler and consistent prep prevent color banding along weld lines.

Power, gas, and the realities of mobile welding

Nothing kills productivity like marginal power. A truck welding setup with a generator that can run both MIG and TIG at full output, plus grinders and a chop saw, changes the day. I carry enough fuel to avoid mid-job shutdowns and dual gas cylinders so I can switch from C25 to argon without hunting a supplier. In winter, regulators and hoses get cold and brittle, so I keep them insulated and check for leaks more often. In summer, heat soak raises gas pressure and flow. If you do not adjust, you waste gas and blow out the puddle.

Wind is the constant enemy, especially around fence lines and open lots. Wind blocks and magnets keep a small work zone stable. If gusts cross 10 to 12 mph, I switch from solid wire to flux-core for carbon steel or wait for a calm window for TIG. You can muscle through wind with higher flow rates, but that becomes expensive and still unreliable.

Access matters too. A trailer might fit where a full truck cannot. For tight alleys or a rooftop railing repair, a compact portable welder paired with a small bottle makes the difference between a day’s work and a reschedule. On emergency welder calls after a break-in or vehicle strike, the ability to cut out a bent section, fit a new panel, and restore function the same night is a service people remember.

Safety that survives scrutiny

Welding near landscaping, painted walls, or fuel lines is not forgiving. Fire blankets, welding screens, and wet down zones are not optional. I stage a fire watch after hot work, and I tell clients up front that it adds time but saves the call to the fire department. On industrial sites, confined spaces around equipment or loading dock pits bring their own rules. Lockout, tagout, and a dedicated spotter keep everyone honest. Grinding sparks travel farther than most expect. A spark that lands in a pile of dry leaves two houses down can smolder for an hour before becoming a problem.

Personal protection is part of the brand. A flash burn on a neighbor’s cornea from a stray arc reflection creates a story that will follow you. I set up screens, position the truck so it blocks sight lines, and control the work zone. The crew wears the right gear, not whatever is in the cab that day. Clients notice, and inspectors do too.

Certified work and when it matters

Not every gate weld needs a stamp, but there are times certifications are non-negotiable. When tying into structural members, attaching to a building’s steel frame, or fabricating guardrails that must meet code, a certified welder with AWS qualifications should be on the torch. Procedure, filler traceability, and weld size matter. Some municipalities require documented weld procedures for structural work, especially on multi-unit developments or public spaces. If a railing forms part of an accessible route, dimensions and performance become a compliance issue, not just a design choice.

I maintain a log of jobs, materials, and processes. It saves time when a property manager calls two years later asking what alloy was used on a stainless stair so they can match it on an expansion. More importantly, it proves that you are not guessing.

The choreography of a good on-site day

The smoothest days follow a rhythm. I start with measurements, not cutting. Fence lines, hinge locations, slab flatness, existing post plumb. If an old gate is getting replaced, I inspect the hinge barrels and base plates rather than assuming they will be reused. I set up the mobile welder where power lines and foot traffic will not mix, then stage materials where sparks will not reach stored lumber or machinery. Tack first, check motion second, commit third. Fit, then weld, then finish, then seal. It sounds basic because it is, but skipping steps for speed invites a second visit.

A field note from a winter job comes to mind. We were fitting aluminum railings on a rooftop terrace with a view worth the wind chill. The steel embeds from the general contractor were out by a finger width along the whole run. TIG would have been beautiful but too slow in that wind, and MIG with a spool gun needed a wind block and a steady hand. We built a temporary corral with tarps, used ceramic backing tape to keep the root clean on corner joints, and sequenced welds in short beads to avoid distortion. The finish work happened in a heated tent to prevent condensation under the clear coat. That job paid for the extra prep the next summer when the owner called to say the gate still latched with a fingertip push despite the heat.

Design choices that look good and work harder

Gates and railings are not only about security. They frame entries, set tone, and guide movement. When clients want wrought iron scrolls beside a modern steel frame, I design for dissimilar section thickness. Thin scrolls burn back if you flood them with heat to tie into a heavy frame. A short TIG fusion pass to set the joint, then a small filler addition, avoids cold lap and keeps the detail crisp. For picket fencing, consistent spacing matters more to the eye than you think. I use jigs even in the field to keep rhythm across runs.

For industrial sites or projects around heavy equipment, the priority shifts. On a loading dock, bollards integrated with rail panels absorb impacts so the rail does not rip out the base plate and leave a hazard. I set expectation for sacrificial parts that can be replaced after an incident without rebuilding the whole system. If forklifts roam the area, I design radiused corners on gate frames and protective rub rails at handle height. Little things prevent big repairs.

Repair work that respects what came before

Not every project starts from scratch. A pipe repair along a fence line or a break at the heel of a gate often reveals why it failed. Sometimes the cause is thin wall tube used where a schedule 40 pipe should have been. Sometimes water got in through an unsealed cap and froze, splitting the member. Repair begins with the root cause. I cut back to sound metal, not just shiny metal. If a vertical post rotted at the base, I replace or sleeve the post and incorporate drain holes or a cap that actually sheds water, not just a decorative piece that traps it.

When patching aluminum panels, avoid mixing alloys that bring galvanic headaches. Match filler, add isolation washers, and seal edges. On stainless rail splices that cracked from stress, I look for support issues rather than just grinding out the crack. A beautiful TIG bead will not fix a post that flexes under load. Sometimes the right answer is a hidden gusset or a larger base plate, ugly until you hide it under a cover plate that blends right in.

Turnaround, scheduling, and the reality of emergency calls

A mobile welder ends up doing triage as often as planned work. When a gate fails at a warehouse around closing, trucks stack up and tempers rise. I carry enough stock on the truck to fabricate a temporary swing leaf, install a secure latch, and return for a full replacement. Clients remember who kept their operation moving. That said, not every emergency fix should become permanent. I make it clear what is temporary, mark welds that need revisit, and schedule follow-up.

Lead times depend on finish. Raw steel fabricated and primed on site can go up the same day. Powder coated systems need off-site time, and stainless takes patience if you want seamless blends. Good communication about sequencing saves headaches. For example, I will often set the posts and hinge line, then remove the gate for powder coat, leaving the site secure with a temporary panel. When the finished gate comes back, it goes straight on without drilling new holes through a fresh finish.

Costs that make sense and where not to skimp

On-site work saves money by eliminating guesswork and rework, not by cutting corners. The biggest budget swings come from finish choices, material selection, and site conditions. Stainless costs more up front but less over time in corrosive environments. Powder coat lasts, but repairs are not as simple as touching up paint. Aluminum keeps weight down for wide gates, which saves on hinge wear and posts, but needs more care during welding and isolation from steel.

I avoid false economies. Undersized hinge barrels, thin wall posts at a driveway, or anchor bolts set too close to slab edges create repairs that cost several times the savings. The right choice gets you a gate that still swings true after five winters of freeze-thaw and a railing that does not wobble when a delivery person leans on it.

What to expect from a qualified mobile welder

A professional arrives ready to work, not ready to wander for parts. The truck or trailer carries a generator, gas cylinders, clamps, levels, grinders, saws, and a mix of consumables for steel, stainless, and aluminum. The welder can explain why TIG or MIG is the right call for each joint, shows AWS certifications when structural work is involved, and documents weld sizes where required. They protect your property while they work, clean up, and leave a result that does not need an apology.

If you stand at your gate on a cold morning and it closes with a quiet click, or you run your hand along a railing and feel nothing but a consistent line, that is the work of a crew that respects both the metal and the site. Welding is more than melting wire into a joint. For custom gates and railings, it is equal parts planning, process, and pride, delivered on site where it counts.

On Call Mobile Welding

917 J Pl Suite 2, Plano, TX 75074

(469) 750-3803