Every industrial company runs into the same fork: bring welders and pipefitters onto the payroll, or bring them in through a specialized supplier. There is no single answer — there are concrete trade-offs across five dimensions: total cost, speed, flexibility, labor risk and document management. Here is the picture, unvarnished, dimension by dimension.
Total cost: the hourly rate misleads in both directions
The naive comparison — internal salary versus supplier rate — always fails, because neither number is the real cost.
With direct hiring, on top of salary come social charges, collective-agreement allowances and overtime, training and requalification of certificates, PPE, absenteeism, recruitment and the most forgotten cost of all: idle capacity. A payroll welder costs the same in the shutdown month and in the month with no joints to close.
With outsourced labor, the rate is clearly above the salary — but it bundles recruitment, documentation, replacement and the supplier margin, and it switches off when the job ends. On continuous workload, the direct route tends to win; on intermittent workload, the cost of idleness eats the difference. The detailed numbers by specialty are in how much a homologated welder costs in Spain.
Speed and flexibility: days versus months
Directly recruiting a homologated welder in a market as tight as Spain's takes weeks or months — and the scarce profile (6G TIG, duplex, alloys) may simply not turn up in time. A supplier with an active pool mobilizes in days and, just as importantly as scaling up, scales down: when the peak ends, the external crew leaves with no restructuring costs. The counterpart is rotation — today's external crew may not be tomorrow's, and part of the knowledge leaves with it. Add the seasonal effect on top: in shutdown season even suppliers run short of people — one more reason to book early rather than search late.
Labor risk and PRL: what transfers and what does not
Honesty is due here: outsourcing does not outsource everything. In Spain, business-activity coordination (CAE) leaves the plant owner with prevention duties of their own, whoever employs the workers. What a good supplier takes on is the operational side: specific occupational-risk training, medical checks, PPE, the preventive resource and civil-liability insurance for its people. It also pays to know the framework: the formal loaning of workers is reserved in Spain for licensed temporary-work agencies (ETT); the usual route with specialized companies is a services contract or scope-based subcontracting, where the supplier directs its own personnel. Demanding clarity on the contractual formula is not legal pedantry — it is what avoids inherited labor liabilities.
Document management: the invisible workload
UNE-EN ISO 9606 qualifications with six-month confirmations up to date, a welder × WPS matrix, A1 posting forms, Social Security certificates, plant access passes: with an in-house crew, all of this is permanent internal administrative work. With a specialized supplier, it travels with the crew — but the buyer must demand access to the documentation and audit it, because in front of the inspector the site answers for whoever is on the scaffold.
Quality and knowledge: the tie-breaker
One dimension rarely makes it into the spreadsheet and decides more than it seems: sustained quality. An internal crew accumulates knowledge of the asset — it knows which line vibrates, which historic weld deserves watching — and that knowledge cuts diagnosis time and rework. A specialized supplier compensates with varied craft: its people weld every month in different plants, different processes, different codes, and arrive trained to pass demanding inspections. The metric that levels the comparison is the rejection rate under testing: demand it documented from your supplier and measure it on your own crew. And if you outsource, negotiate continuity of the same people across campaigns — rotation is negotiable, and a stable external core captures part of the asset knowledge at no fixed cost.
When each model makes sense
Direct hiring pays off with stable, predictable workload across the whole year, on assets where history and knowledge of the installation are gold, and when the company has the structure to manage recruitment, training and paperwork.
Outsourcing wins in planned shutdowns and turnarounds, projects with sharp peaks, work in regions with no installed crew, unplanned emergencies and scarce profiles that do not justify a year-round payroll seat.
The hybrid model reality imposes
In practice, most industrial plants converge on the same design: an internal core team sized for the stable minimum workload, and a mobilization partner for everything above it. It is the most resilient model — it caps fixed cost, keeps critical know-how in-house and scales without shocks. The key question stops being "internal or external" and becomes the choice of partner: the criteria to evaluate one (documentation, lead times, replacement plan, transparency) are in our guide on how to hire homologated welders in Spain.
In short
- Compare total costs, not salary against rate — idleness and administration count.
- Speed has economic value: every week waiting for a scarce profile is a stopped site.
- PRL transfers partially: the operation yes, the owner's coordination duties no.
- Documentation: who manages it can change; who answers for it on site cannot.
- Quality: measure the rejection rate under both models — it is the objective tie-breaker.
- Hybrid: a minimal internal core plus a partner for the peaks is the design that ages best.
Iron Pulse supplies specialized crews of homologated welders, pipefitters and mechanics for projects and shutdowns across Spain, with a complete documentation dossier. See our services or talk to the team about the design that makes sense for your plant.
