Planning coating work during a plant shutdown

Coating work fits inside a plant shutdown when it is prepared before the shutdown: survey of surfaces and access, equipment and products pre-staged, heating and dehumidification sized, shifts organized around recoat windows, inspection hold points built into the schedule, contingencies reserved in the schedule and a lessons-learned review at the end. Cure time is planned as a task, not as float.

During a shutdown, every hour costs lost production, and coating often comes after mechanical, piping and welding work. It then inherits accumulated delays, while its own time requirements (preparation, ambient conditions, recoat, cure) cannot be compressed. This guide is for shutdown managers, planners and maintenance managers in Quebec and Ontario. It extends to the whole plant what our article on tank lining within a shutdown window explains for a single tank, and complements our project management page.

Why does coating work slip during shutdowns?

Coating work slips during shutdowns because it is planned on its application time, while preparation, waiting for ambient conditions, recoat intervals and cure take up most of the time. It also depends on other trades: until welding is finished in an area, that area cannot be blasted.

Three causes keep coming back:

• Poorly coordinated sequence. Coating is placed at the end of the schedule, with no reserved window.
• Unplanned ambient conditions. Cold, humidity or condensation stop application.
• Surface surprises. More advanced corrosion, an incompatible old coating or lead found when equipment is opened.

Each one is dealt with before the shutdown, while there is still time to order, survey and adjust the sequence.

What should be surveyed before the shutdown?

Survey everything that can be surveyed while the plant is running: surfaces, condition of the existing coating, access, likely ambient conditions and interfaces with other work. The survey turns assumptions into quantities and durations.

• Surfaces and quantities. List of items, areas, difficult details (edges, bolting, supports).
• Existing condition. Coating type, adhesion, thickness, possible lead or other metals.
• Access. Scaffolding, lifts, manways, confined spaces per CSA Z1006 and provincial regulations.
• Conditions. Likely steel and air temperatures in the shutdown season, moisture sources, ventilation.
• Interfaces. Hot work, mechanical work, insulation, hydrostatic tests before or after coating.

The survey can also include simple tests: adhesion of the old coating, a compatibility patch on a small area, soluble salt readings on surfaces exposed to the process. Their results set the preparation method and avoid discovering during the shutdown that a planned overcoat is not possible. They also help order the right products in the right quantities, since supply lead times cannot be recovered once the plant is down.

When some items can be treated without a shutdown, take them out of the window: our article on in-place coating of in-service equipment presents those options.

Which equipment should be pre-staged?

Pre-stage everything whose absence would stop the job: products in sufficient quantity with their batches, abrasive, compressors, dust collectors, heating, dehumidifiers, lighting, ventilation and inspection instruments. The goal is to start the first shift at full capacity.

Products are stored at the temperature the data sheet requires, protected from freezing. Measuring instruments (thickness, dew point, profile) are calibrated and checked before the shutdown. Wear parts for blasting and spray equipment are doubled up. Blasting in operating plants with dust control also calls for containment set up in advance where possible.

How to size heating and dehumidification?

Size heating and dehumidification from the likely ambient conditions and the ranges the data sheets require: minimum surface temperature, maximum relative humidity and margin above dew point. They are used during preparation, application and cure.

Dehumidification often lets blasted steel be held without flash rust for longer, which decouples blasting from application. Heating keeps the cure temperature. Both need power or fuel reserved in the shutdown plan. Readings are taken per ISO 8502-4 or ASTM E337 and recorded. Our article on cold-weather epoxy application details winter precautions.

How to organize the shifts?

Organize shifts around the coating's time requirements rather than working hours: blasting, application and recoat follow one another within the data sheet windows, and cure continues overnight under controlled heating.

• Staggered blasting and application shifts, so blasted surfaces are coated within the accepted interval.
• Condition monitoring during shifts with no application, especially at night when condensation forms.
• Written handover between shifts: areas prepared, coats applied, times, conditions, nonconformances.
• Fatigue and safety. Extended shifts increase errors; the plan includes relief crews.
• One coating lead per shift, who decides whether conditions allow application and signs the shift log, so the decision does not fall to whoever happens to be on site.

Where should inspection hold points go?

Place hold points at the stages where an error becomes invisible afterward: end of preparation, before each coat and final inspection. They appear in the schedule as tasks, with an inspector available at the planned time.

The table below summarizes the usual hold points and what they check.

Independent inspection can be assigned to our coating inspection service.

Which contingencies should be planned?

Plan contingencies for known risks: more extensive corrosion than expected, unfavourable ambient conditions, delays from other trades, a defect found at inspection. Each contingency has a response decided in advance and reserved time.

• More extensive corrosion. Steel repair method and extra quantities approved in advance.
• Unfavourable conditions. Reserve heating or dehumidification capacity.
• Upstream delay. Coating areas reordered to work where access is released.
• Defect at inspection. Repair method defined in the specification, as explained in our article on coating failure modes.
• Possible deferral. Items that can receive temporary protection and be completed at the next shutdown.

How to run the lessons-learned review?

Run the lessons-learned review shortly after the shutdown, with the records in hand: gaps between planned and actual durations, causes, nonconformances, consumption and conditions encountered. The result feeds the survey and schedule of the next shutdown.

The thickness, conditions and repair records also remain the basis for maintenance and rehabilitation of the treated items. System selection follows our protective coatings approach. Our crews and qualified subcontractors work from LaSalle, including Rouyn-Noranda and Sudbury. Send the list of items, photos and the shutdown window through the request a quote form: pricing on consultation, reply within 24 business hours.

Frequently asked questions

When should coating preparation for a shutdown start?

As soon as the shutdown work list takes shape, so the survey can be done while the plant runs and products and equipment can be ordered in time.

Can cure be shortened to save time?

Only within the limits of the data sheet, for example by heating to stay within the accepted temperature range, or by choosing a faster-curing system from the start. Returning to service too early compromises the coating.

Who coordinates coating with the other trades?

The shutdown manager, with a coating lead who keeps the sequence, conditions and hold points up to date at every shift.

What about items that do not fit in the window?

Treat them in operation where possible, give them temporary protection, or defer them to the next shutdown, based on a decision made before the shutdown rather than during it.