How to Vet a Marine Metal Fabrication Shop Before You Hire Them

The marine metalwork decision is rarely a question of whether the part can be built. It is a question of who is going to build it without forcing a re-fit, a re-quote, or a re-schedule before the work holds. The honest call between shops is not made on a single price line — it is made across six well-defined criteria that together separate a real marine fabrication shop from a generic welder with a marine website.

This guide walks the six: shop-floor capacity and equipment, marine-specific certifications, portfolio depth in marine work, lead-time reliability, quote and SOW transparency, and post-delivery support. Each criterion is structural — the kind of thing a buyer can confirm on a site visit or in a quote conversation before any deposit changes hands. The framing applies whether the project is a 24-hour pulpit repair or a structural hull refit on a 120-footer.

The reference standard throughout is the Lloyds, ABS & USCG certification stack that governs marine metalwork on classed vessels, plus AWS D1.2 for aluminum structural work. DolFab's Fort Lauderdale shop has run on that stack for over 40 years, and the structural reason this set of criteria exists is that the right shop calls that history a baseline rather than a pitch.

1. Shop-Floor Capacity and Equipment

The first thing a yard visit confirms is whether the shop can do the work in-house, or whether it has to hand the part off to a sub-trade at every step. A shop with welding, machining, forming, and finishing on a single floor removes the handoff cost — the part moves through one set of hands, on one floor, in one schedule. A shop that has to send the part out for forming or finishing introduces three days of in-transit each direction plus a coordination cost that does not show up on any quote line.

What to look for on a walk-through:

Floor space and crane capacity. A 10-ton overhead crane and a clean floor large enough to set a 30-foot hull section is a meaningful capability. Yards without overhead crane will set the same part on saw-horses and lift it with forklifts; that is workable for small parts and a real constraint on a structural build.
Welding bays at dedicated stations. A shop that has a row of dedicated welding bays with fume extraction, backing gas for stainless TIG, and a separate aluminum room is set up to run production work. A single-bay shop with one welder on a roll-around table is set up for short-run repair work; it is not set up for a six-week structural project.
Machine tools in-house. Lathe and mill work in-house means the shop can make its own fittings, sleeves, and standoffs to spec. A shop that sub-contracts all machining introduces a 5–10 working day slack into the schedule every time a turned fitting is needed.
Finishing room. A separated finishing room with grinding, polishing, and passivation stations is the only way to deliver an owner-visible finish grade (#4 brush or #8 mirror on stainless) that meets the marine spec. A shop that finishes at the welding bench cannot deliver above a #4 mill-grade.
Ventilation and overhead crane. Both are non-negotiable for production work. A shop that cannot weld in a ventilated bay or lift a 300-lb plate part with the crane is not the shop for a structural project.

If the floor is small and the equipment is single-purpose, the shop can still be honest about the work it takes on. The structural question is whether the shop's capability matches the project that is being quoted — and the only way to confirm is a pre-quote walk-through or a phone conversation that names the equipment clearly.

2. Marine-Specific Certifications

Certifications on marine metalwork are not a checkbox. They are a procurement gate on classed vessels and a quality floor on everything else. The right shop holds certifications on its welders and its procedures, and the right buyer asks for the records before the deposit.

Lloyds, ABS & USCG certification on welders. A Lloyds-classed hull repair, a structural-hold-point on an ABS-surveyed vessel, or a USCG-inspected passenger hull all requires WPS (Welding Procedure Specification), PQR (Procedure Qualification Record), and welder qualification records on file. The buyer should ask for: the welder's qualification records on the relevant alloy and joint, the WPS in force for the project, and confirmation that the shop has been audited on this stack recently.

AWS D1.2 for aluminum structural. Aluminum structural work — T-tops, radar arches, hardtop support structure, leaning-post structure — is governed by AWS D1.2 in the US. A shop that runs aluminum without holding D1.2 qualifications on the welders is running work without a structural floor. The D1.2 question is also the right test for a shop that claims to do "marine aluminum work" but cannot produce the records.

Quality systems documentation. Beyond the welder certifications, look at whether the shop produces traveler documentation, weld inspection records (visual, dye-pen, ultrasonic, X-ray as required), and material traceability on the mill-cert side. A shop that does not track heat numbers and lot certifications on incoming plate is operating in the dark, and that deficiency surfaces as a hidden cost on the project if it emerges mid-build.

Classification-society experience. The shop does not need to be a class society, but it should have active work against at least one class (Lloyds, ABS, USCG-inspected passenger hull, RINA, DNV) in the last 24 months. Class work is its own discipline — the surveyor hold-points, the audit trail, the document control — and a shop that has not done class work recently will not run class work efficiently the first time.

On most buyer projects the certification floor is a qualification: the buyer wants to know that the shop's welders are qualified to do the work without re-quoting an unexpected $4,000 weld qualification at the start of the project. Confirming that the certifications are already on file is the step that protects the quote.

3. Portfolio Depth in Marine Work

A marine fabrication shop's portfolio is the most reliable signal that it has structural familiarity with the work being quoted. A gallery of generic metalwork — a residential railing here, a structural I-beam there, a commercial hardware bracket — is not a marine portfolio; it is a shop that takes marine work but does not run on it every day.

What makes a marine portfolio real:

Specific case studies in marine. Pulpit rebuilds on production sportfishers, structural hull repair on a Lloyds-classed hull, custom T-top fabrication on a center console, custom stern rail on a sportfisher, rudder hardware on a commercial vessel. The shop should be able to walk through two or three case studies matching the project at hand.
Materials in marine-grade alloys. Look for 316L stainless, 2205 duplex stainless, 5086 / 5083 / 6061 aluminum, and marine bronze in the gallery. A portfolio full of mild steel, hot-rolled plate, and architectural aluminum is a structural steel shop, not a marine shop.
Documentation of class work. Yacht refit, classed-vessel repair, class surveyor hold-points documented — the presence of these in the portfolio correlates with the shop being able to manage the audit trail on the next project.

A site worth running before the project is the project portfolio — case studies indexed by scope and alloy grade, with the failure mode and the structural answer on each one. The portfolio is not marketing; it is the buyer's primary research tool for confirming the shop runs marine work every week.

4. Lead-Time Reliability

Lead-time reliability is the difference between a shipping schedule and the same schedule two weeks late at the wrong time of year. South Florida fabrication queues run tight in season (October–May refit window, pre-hurricane prep, Fort Lauderdale International Boat Show compression), and a non-rush 6-week custom build can quietly stretch to 8 weeks under load.

The right question is reliability — not speed — and the right shop gives the buyer a lead-time in writing before deposit.

What to ask:

Queue depth at booking. An honest shop will tell the buyer what the queue looks like at the start of the project and how the work fits into the schedule. A shop that quotes a 4-week lead time with a 6-week queue when the work is actually booked is overpromising before the work starts.
Rush capacity vs. scheduled work. Marine emergencies happen. The shop with a working rush track — pulpit repair before a charter, stanchion replacement in a pre-passage yard period — can compress a 6-week build to 2–3 weeks at the cost premium. The shop without a rush discipline cannot.
In-stock materials. A shop carrying marine-grade inventory (316L stainless tube and plate, 2205 duplex, 5086 aluminum plate, common marine bronze) can pull a project start forward by days. The full material sourcing approach is worth asking about explicitly.
Classification-society availability. For class-required work, surveyor schedule can compress or extend the lead time by days. Confirm with the shop or directly with the surveyor that the schedule is realistic before locking the refit window.

Lead-time reliability is the criterion that converts a "real marine metalwork shop" into a "marine metalwork shop on schedule" — and the latter is the operational difference on the project.

5. Quote and SOW Transparency

A marine fabrication quote is almost always the largest single document on the project. The right shop produces a line-item quote that names the alloy, the finish grade, the test method, the lead time, and the classification documentation — not a number on a one-page estimate with a unit price.

The buyer's structural questions to ask of the quote:

Material call-out. The quote should name 316L stainless by name, not "stainless." 2205, 5086 aluminum, 2205 duplex, and marine bronze are not generic specs; the materials either appear in the quote or the quote is leaving the spec to assumption.
Finish grade. #4 brushed, #8 mirror, mill finish — the finish grade should be specified explicitly, because the cost difference is real. A quote that does not specify finish grade is not a marine quote; it is a price.
Test and inspection. Visual, dye-pen, ultrasonic, X-ray — the inspection methods should be specified for class-required work, with the documentation deliverable (mill cert, weld procedure, traveler, photo log) named in the quote.
Classification documentation. For class work, the WPS, PQR, and welder qualification records should be referenced. The shop should name the attending surveyor and the hold-point schedule.
Lead time and lead-time penalty. The quote should name the lead time against a clear schedule and the change-order cost if the lead time elongates. This is the structural protection on a refit window.

DolFab's seven-step project workflow is the SOW framework the shop runs every project through — site survey, scope and material call-out, SOW review, fabrication, in-process QA, finish and documentation, delivery and follow-up. The buyer should expect a quote that walks the project through the same workflow. A shop that quotes the price without the workflow is leaving scope assumptions on the table; those assumptions become change orders on the project.

6. Post-Delivery Support

The post-delivery support criterion is the one that decides whether the shop is a vendor or a project partner. Marine fabrication is iterative — the part delivery is mid-project in the lifetime of the vessel. A shop that follows up after delivery is a shop that stands behind the work; a shop that disappears at invoice is a shop that does not.

The structural marks of post-delivery support:

Warranty on the work. A 12-month minimum workmanship warranty on the part, with the materials warranty flowing through from the mill cert. A shop that does not commit to a warranty is a shop that will not run the part back at their cost on a failure.
NDT and documentation on the part. Mill cert, weld procedure, traveler documentation, NDT report — the same documentation that ran on the project should be in the deliverable to the buyer. The buyer should request these on delivery and confirm that they cover the work as delivered.
Install support. For classed-vessel work, an installer in the yard who has the shop's documentation and the shop's phone number on the back of it is a real asset. A shop that cannot support the install is a shop that has shipped the documentation responsibility to the yard.
Follow-up across the refit. A phone call or email 30 days after delivery, with a defined follow-up schedule on warranted parts. A shop that runs the follow-up is a shop that will identify a finishing issue or a documentation gap before the next yard period and stand behind the correction.

The 30-day, 90-day, and yard-period follow-up is the criterion that converts the project from "build the part" to "support the vessel" — and the support role is the structural reason a marine shop with a four-decade Fort Lauderdale history is a fundamentally different operation than a generic welder with a marine website.

Making the Call

The honest call between marine fabrication shops is made by walking all six criteria against the project at hand. Capacity, certifications, portfolio, lead-time reliability, SOW transparency, and post-delivery support — these are the structural questions, and the answers are either on the quote or they are not.

When the criteria line up, the project converts. When they do not — the shop is general, the certifications are thin, the portfolio is not marine, the lead time is a number without a queue, the quote is a one-page estimate — the project should walk.

Choosing a marine metalwork shop for a specific project? Request a quote with the scope, alloy, finish grade, lead-time target, and classification status, and we will give you an honest answer on whether DolFab is the right shop for your work, with a real line-item SOW and a real schedule against the project. Our seven-step project workflow takes the part from site survey through installation, with surveyor-grade documentation at every step. Our project portfolio and owner and captain reviews document the work and the customer experience across the Fort Lauderdale marine corridor.

— DolFab