Independent welding consultant for technical welding issues

A cracked weld, a batch of pipework rejected by the client, or a supplier proposing a different welding procedure than you expected: at moments like these you want to know quickly where you stand. As an independent welding consultant, DEHAAS gives you that clarity. We analyse the problem, establish the cause on the basis of facts and advise on a solution that is technically sound and workable on the shop floor.

Independent, no sales interest
Root cause backed by facts
Hands-on, on site across the Netherlands
Clear report for all parties

Ask your technical question Call +31 6 29 72 37 91

DEHAAS is an independent welding consultancy based in Menaam, Friesland, working throughout Europe and North America. We do not sell welding equipment, consumables or certificates, so we have no stake in any particular outcome. We work hands-on: on the shop floor, at the workpiece and alongside the people doing the work. For wider questions on material selection, process choice and manufacturability, this service links up with our welding engineering service.

Weld defect analysis

Cracks, porosity, lack of fusion or distortion always have a cause, and it rarely lies with the welder alone. Material, joint preparation, parameters, preheat, consumables and site conditions usually interact. We map these factors systematically before drawing conclusions.

Assessment of the workpiece, welding records and production conditions
Comparison of actual practice with the WPS and the supporting WPQR
Advice on further investigation, such as NDT, macro examination, hardness testing or fractography by a laboratory
Classification of imperfections to ISO 6520-1 and assessment against the agreed ISO 5817 quality level

The result is a substantiated root cause and concrete measures to prevent recurrence. For an overview of common defects, see our article on weld defects and their causes.

Repair advice

Not every rejected weld needs to be cut out. Sometimes a local repair is technically sound; sometimes a repair creates new problems, for example through additional heat input into sensitive material or locked-in stresses. We assess each case on its merits.

Good repair advice specifies how the defect is removed, how complete removal is verified, which procedure is used for the repair and which inspection follows. Where needed we prepare a repair WPS and check whether the existing qualification covers it. For pressure equipment or structures in higher execution classes, we agree the approach with the inspection body or client so that the repair is also formally accepted.

Second opinion and arbitration in disputes

When client and supplier disagree about weld quality, interests collide. An independent assessment brings the discussion back to the facts: what was agreed, which standard and quality level apply, and does the delivered work comply?

Review of specifications, drawings and contractual requirements
Assessment of inspection reports, NDT results and qualification records
Our own visual inspection to ISO 17637 where relevant
A written report with findings, rationale and conclusion

Because DEHAAS supplies products to neither party, all involved can use the report as a basis for resolution.

Support for purchasing and engineering

Many welding problems start before an arc is struck: in the specification, on the drawing or in the purchase conditions. We help engineering and purchasing define welding requirements properly up front.

Drafting or reviewing welding specifications and purchase requirements
Reviewing supplier documentation such as WPSs, WPQRs and welder qualifications
Checking weld symbols to ISO 2553, joint designs and weld accessibility
Advice on the appropriate EN 1090-2 execution class or ISO 3834 level

We can also review incoming quotations: do the qualifications offered cover the work, and is the proposed inspection scope proportionate to the risk?

Training on the job

Knowledge sticks best where it is used. Our on-the-job training is built around your own products, processes and documents: reading and applying a WPS, recognising imperfections, measuring heat input and interpass temperature correctly, or assessing welds against ISO 5817. It is aimed at welders, planners, quality staff and engineers, so that your team makes better-founded decisions independently.

How we handle a consultancy question

Every assignment starts with a short intake to establish the question, the available data and the desired outcome. The investigation follows, on site or from documents, with interim feedback when decisions are needed. You receive clear advice or a report with concrete next steps. For recurring issues we capture the solution in work instructions or the WPS, so the improvement carries through to the next production run.

Frequently asked questions

For recurring weld defects, rejection by a client or inspection body, doubts about a repair, a dispute with a supplier, or a new product whose welding approach is not yet defined. The earlier you call someone in, the smaller the consequential damage tends to be.

Yes. The report is factual and based on standards, specifications and observations. Because DEHAAS is independent, both parties can rely on it. Court proceedings impose additional requirements on experts, which we agree with you beforehand.

Yes. DEHAAS is based in Menaam and works throughout Europe and North America, in workshops, on construction sites and at suppliers' premises.

We advise on which tests are worthwhile, define the scope and assess the results. Testing itself is carried out by an accredited laboratory; interpretation and advice remain with us.