Fabrication
Welding and Metal Fabrication
In short: Welding on a vehicle chassis is a structural operation with a specification, not a general repair skill, which is why where you weld matters as much as how well you weld it.
- Typical range
- $500 to $15,000+
- Labor hours
- 3 to 70 hours
- Updated
Welding on vehicles is a structural discipline rather than a general repair skill. The equipment is the least interesting part. What matters is knowing where a weld is permitted, what the material actually is, what the weld does to the material around it, and what has to be protected before the arc is struck.
Where you weld
Every chassis has locations where sectioning and welding are acceptable and locations where they are not, and the difference is not aesthetic.
On unibody vehicles, including Sprinter, Transit and ProMaster, manufacturers publish approved sectioning points, required weld types and components designated replace-only because they are made from high-strength steel that loses its properties when heated. Welding outside that procedure produces a vehicle that is the correct shape and behaves differently in the next impact.
On ladder frames there is more latitude, but welding across a rail flange at a high-stress location, or adding a stiff reinforcement that creates a new stress concentration at its ends, both produce cracks later. A reinforcement that stops abruptly is a crack initiator, which is why plates get tapered and ends get staggered.
We follow the published procedure where one exists and standard structural practice where one does not. Related work is covered under frame straightening.
Materials
Steel. Mild steel across most chassis and body structure, high-strength steel in designated crash structure. Identifying which is which matters, because heating high-strength steel and straightening it produces a component at a fraction of its designed strength.
Aluminium. Trailer frames, some body structure, an increasing amount of modern commercial bodywork. Different equipment, different technique, and filler selection depends on the alloy. Aluminium also loses strength in the heat affected zone around a weld, so an aluminium repair often needs reinforcement that an equivalent steel repair would not.
Stainless. Food service equipment, tanks and anything where corrosion resistance justifies the cost.
Dissimilar metals. Aluminium fastened or bonded to steel needs isolation, because galvanic corrosion at that junction will destroy the aluminium. This is designed in rather than dealt with afterwards.
Preparation, which is where the risk is
Welding on a vehicle without preparation damages things a long way from the weld.
Batteries disconnected and control modules isolated, because welding current finds its own path back and that path may run through an ECU. Ground clamped close to the weld so current does not travel through wheel bearings, which pits their races permanently. Fuel and propane systems isolated and verified. Whatever is on the other side of the panel checked, because insulation, wiring and upholstery all ignite readily and a fire inside a wall cavity is discovered late.
Corrosion protection afterwards, on every weld and every heat affected zone, because bare hot-worked steel in a coastal climate rusts quickly.
What we do
Structural repair welding on chassis and frames, crack repair with proper preparation and reinforcement, frame section replacement, trailer frame and tongue repair, hitch, receiver and gooseneck installation and repair, commercial body and subframe repair, equipment mounting to structural standard, tank and enclosure fabrication, exhaust and stack repair, and full structural rebuilds on restoration projects.
On municipal and utility vehicles this extends to body structure on refuse packers, utility bodies, bucket truck subframes and snow plow mounting, all of which see loads that a general body shop rarely encounters.
What it costs
| Job | Typical range | Hours |
|---|---|---|
| Small repair weld | $500 to $1,500 | 3 to 7 |
| Crack repair with reinforcement | $1,500 to $5,000 | 7 to 22 |
| Trailer tongue or hitch repair | $900 to $3,000 | 4 to 13 |
| Frame section replacement | $4,000 to $10,000 | 18 to 45 |
| Full structural rebuild | $10,000 to $15,000+ | 45 to 70+ |
Structural labor is $260 per hour. See the pricing page.
In shop only
All welding here happens at the Yorba Linda facility. No mobile, no on-site.
Structural welding needs controlled conditions, proper fixturing so the part does not move as it cools, the ability to measure the chassis before and after, and equipment that does not travel well. A structural weld made in a parking lot cannot be verified, and on something carrying a vehicle down the freeway that is not a corner worth cutting.
If the vehicle is not drivable, call and we will talk through the tow.
Estimates are $150 and credited back against an authorized repair.
Certification and documentation
Structural welding on a commercial or municipal vehicle frequently has to be documented rather than simply performed, because the vehicle is part of a regulated fleet or because an insurer will want evidence of how a repair was carried out.
We photograph preparation, fit-up and completed welds, record the process, filler and material identification, and keep that with the job file. On a chassis repair we also keep the before and after measurement sheets, since a weld that is sound on a frame that is still out of specification is only half a repair.
That record matters in three situations that come up regularly: a fleet audit, a subsequent insurance claim where a prior repair is questioned, and resale, where a documented structural repair is worth considerably more than an undocumented one that a buyer's inspector finds.