# Planning a Coating Outage: 8 Steps from Surface Prep to Start-Up Polylloy coatings require abrasive blasting to Society for Protective Coatings (SSPC) SP10 / NACE No. 2 near-white metal with a surface profile over 3 mils (75 µm). That blast sits inside an eight-step outage plan: grade selection, scheduling, preparation, condition control, supervised application, film thickness checks, defect repair and heat-cure activation during start-up. **Category:** Articles **Written by:** Surjit Gill **Last updated:** Oct 12, 2026 **Source:** https://signals.polylloycoatings.com/articles/coating-outage-planning-steps --- ## Coating Outage Planning: Key Points - Polylloy coatings need abrasive blasting to SSPC-SP10 / NACE No. 2 near-white metal with a surface profile over 3 mils (75 µm); a site that cannot reach that standard is not a fit. - Application conditions come from the bulletins: steel surface 10 to 50 °C (50 to 122 °F), relative humidity below 90 %, and the steel at least 5 °C above the dew point. - Most grades go on as a single coat, which removes the return visits of a primer, build-coat and topcoat system; FlueGard®-455CHT is the exception and needs two coats. - Dry film thickness is verified against each grade's bulletin range, and defects are found and recoated before final cure, with holiday testing where the specification calls for it. - Final heat cured activation is completed during start-up using process heat; CorrosionGard®-160S is the ambient-cure exception, with a 160 °C service limit. - Certified partners apply the coating; Polylloy formulates, supplies, specifies and supervises. Polylloy coatings require abrasive blasting to Society for Protective Coatings (SSPC) SP10 / NACE No. 2 near-white metal with a surface profile over 3 mils (75 µm). That blast sits inside an eight-step outage plan: grade selection, scheduling, preparation, condition control, supervised application, film thickness checks, defect repair and heat-cure activation during start-up. Coating outage planning is the sequence of decisions and hold points that fits surface preparation, application, inspection and cure of a protective coating into a plant shutdown. The eight steps are: 1. Confirm service conditions and select the grade. 2. Build the coating scope into the shutdown schedule. 3. Prepare the surface to SSPC-SP10 / NACE No. 2 near-white metal. 4. Control surface temperature, humidity and dew point. 5. Apply the coating under supervision. 6. Verify dry film thickness. 7. Inspect, test and repair defects before final cure. 8. Complete heat-cure activation during start-up. ## Service Conditions and Grade Selection Come Before the Coating Outage Service conditions and grade selection are settled before anyone books blasting equipment, because the grade decides the film build, the number of coats and how the cure is completed. ### Data the Plan Starts From Polylloy's site and data review starts from normal and peak temperatures, gas chemistry, condensation, particulate loading, substrate condition and shutdown constraints. Those inputs point to a grade by service limit: - [CorrosionGard-160S](https://www.polylloycoatings.com/corrosiongard): 160 °C. - FlueGard-225SQC: 225 °C. - [StackGard®-255SQW](https://www.polylloycoatings.com/stackgard): 255 °C. - FlueGard-425S: 425 °C, with peaks to 500 °C. - FlueGard-455CHT: 455 °C (850 °F). - KilnGard®-600SCW: 600 °C. - WearGard®-625S: 625 °C. The full list of [coating grades by temperature and gas chemistry](https://signals.polylloycoatings.com/listicles/coating-grades-temperature-chemistry) sets out what each grade resists. ### Short Baghouse Shutdowns FlueGard-225SQC is designated Sprayable Quick Cure in its bulletin and is rated for baghouses, electrostatic precipitators (ESPs) and ducts to 225 °C (437 °F). Whether it fits a given shutdown depends on area, access, blasting and humidity control, which Polylloy reviews per project. ## Coating Scope Built Into the Shutdown Schedule Coating scope belongs in the shutdown schedule from the first planning meeting, not added once the equipment is open. ### One Coat Against Three A conventional high-performance system typically needs a primer, a build coat and often an ultraviolet-resistant topcoat, which Surjit Gill, Polylloy's co-founder, describes as separate visits to the same surface. Each visit adds its own access, preparation and inspection to the outage. The KilnGard-600SCW, StackGard-255SQW, FlueGard-425S and CorrosionGard-160S bulletins give single-coat film builds. FlueGard-455CHT requires two coats, and the schedule should show both. ### What Sets the Time on Site Time on site depends on the area exposed, access and scaffolding, the refractory removal sequence, blasting and containment, condition control, the number of coats and the inspection hold points. There is no fixed figure. On kiln shells, the coating goes on while the refractory is out, between demolition and bricking, so it rides inside the reline already planned; the reline sequence is covered under [coating corrosion behind a refractory lining](https://signals.polylloycoatings.com/articles/corrosion-behind-refractory-lining). Stack and duct sections can be coated on the ground or before assembly. ## Surface Preparation to SSPC-SP10 / NACE No. 2 Near-White Metal Surface preparation is the step that decides whether a site is a fit at all. ### The Standard Every Polylloy bulletin specifies abrasive blasting to SSPC-SP10 near-white metal with a surface profile over 3 mils, and most also cite NACE No. 2 and 75 µm. The FlueGard-455CHT technical data sheet states SSPC SP-10 near white with a profile over 3 mils peak to valley. A site that cannot blast to that standard is not a fit for these coatings, whatever the corrosion problem. Confirm blasting access, abrasive supply and containment before the outage date is fixed. ### Baghouse Specifics In a baghouse, remove dust and deposits from hopper valleys, stiffeners and tubesheet edges before blasting. Repair perforated or thinned plate first, because a coating does not restore wall thickness. Hopper and housing protection choices are compared in [baghouse corrosion protection options](https://signals.polylloycoatings.com/listicles/baghouse-corrosion-protection). ## Application Conditions: Surface Temperature, Humidity and Dew Point Application conditions are printed in the bulletins and have to hold for the whole application, not only at the start of a shift. ### Bulletin Limits The steel surface must be 10 to 50 °C (50 to 122 °F), relative humidity (RH) below 90 %, and the steel at least 5 °C above the dew point. These limits are printed in the KilnGard-600SCW, FlueGard-225SQC, FlueGard-425S, StackGard-255SQW, CorrosionGard-160S and WearGard-625S bulletins; the FlueGard-455CHT data sheet lists none, so confirm them per project. Kiln shells and ducts may still be hot after shutdown, and enclosed baghouses trap moisture. Plan cooling, heating or dehumidification so the conditions hold throughout. ### Recording Measure and record surface temperature, RH and dew point before and during each application shift. If the steel drops to within 5 °C of the dew point, the bulletin conditions are no longer met and application stops. ## Supervised Partner Application of the Coating Supervised partner application keeps the coating within the specification that was written for the asset. ### Who Does What A certified Polylloy partner applies the coating; Polylloy specifies, trains and supervises. Roles, contracts and partner selection are covered in [industrial coating contractors and supervision](https://signals.polylloycoatings.com/articles/industrial-coating-contractors). ### Application Control Methods follow the bulletin. KilnGard-600SCW goes on by air spray, roller or brush, and FlueGard-225SQC by airless spray, air spray or roller; FlueGard-225SQC and StackGard-255SQW are two-component grades mixed 4:1 by volume. Water-based grades, KilnGard-600SCW and FlueGard-455CHT, are thinned only with distilled water. Partners track mixing, method, wet-film checks and repair procedures for every area coated. ## Dry Film Thickness Verification After Application Dry film thickness (DFT) verification confirms that the barrier on the steel matches the specification. ### During and After Wet-film checks run during application, then DFT readings are taken against the grade's bulletin range, including welds, edges and stiffeners. Example ranges: - KilnGard-600SCW: 15 to 25 mils (0.38 to 0.63 mm), single coat. - CorrosionGard-160S: 20 to 30 mils, single coat. - FlueGard-455CHT: 16 to 20 mils (400 to 500 µm) total over two coats. ### Why Both Limits Matter Low film leaves less barrier between the steel and the gas. Film above the bulletin maximum, for example 25 mils for KilnGard-600SCW, is outside the specification and is corrected before cure. ## Defect Inspection, Holiday Testing and Repair Before Final Cure Defect inspection is the last chance to fix the film while the equipment is still open. ### Inspection Inside a Baghouse or Kiln The FlueGard-225SQC and KilnGard-600SCW bulletins state that, before final cure, the film can be inspected for thickness and integrity and any defect recoated. Check visually for pinholes, dry spray, runs and missed areas, with adequate lighting in hopper valleys and behind stiffeners. Continuity, or holiday, testing is added when the specification calls for it. Closeout also covers visual acceptance and punch-list completion. ### Repair Mark, clean and recoat defects to the project repair procedure, then re-inspect. Records go to the plant owner, and later condition checks can be arranged through Polylloy's [inspection and maintenance services](https://www.polylloycoatings.com/industrial-inspection-maintenance-services). ## Heat-Cure Activation During Plant Start-Up Heat-cure activation is the step that finishes the coating, and it happens when the plant comes back on line. ### Activation at Start-Up Final heat cured activation is completed during start-up using process heat. The heat cure activates the coating's chemical bonding with the steel and its internal bonding, so the start-up is part of the coating job. ### What the Start-Up Approach Depends On The start-up approach is agreed per project by Polylloy's technical team, considering grade, film thickness, equipment and, in kilns or [lined stacks](https://signals.polylloycoatings.com/articles/refractory-lined-stack-coating), the refractory supplier's heat-up procedure. Cure energy, process heat against external heat, is a cost factor. CorrosionGard-160S is the ambient-cure grade; its 160 °C (320 °F) figure is a service limit, not a cure temperature. Grade-specific notes are on the [KilnGard kiln shell coating](https://www.polylloycoatings.com/kilngard) and [FlueGard baghouse and duct coatings](https://www.polylloycoatings.com/fluegard) pages. ## Deciding Whether Your Plant is Ready for a Coating Outage Deciding whether a plant is ready for a coating outage comes down to three questions: - Can the site blast to SSPC-SP10 with a profile over 3 mils, hold the application conditions, and bring the equipment back through a start-up that completes heat-cure activation? - Is the scope defined on a specific asset, with an outage date set? - Are the engineering decision makers involved? If the answer to the first is no, discuss alternatives with Polylloy before the outage. When all three are yes, [book a Coating Performance Review](https://www.polylloycoatings.com/contact) and share equipment type, coated area, operating conditions (temperature, gas chemistry, abrasion), location and outage timing. ### FAQs **How Fast Can You Heat a Coating During Cure?** The heating rate is set for each project: Polylloy's technical team agrees the start-up approach based on the grade, film thickness, the equipment and, in kilns or lined stacks, the refractory supplier's heat-up procedure. Final heat cured activation is completed during start-up using process heat, so the cure follows the plant's own start-up. **What Temperature Limit Applies to an Ambient Cure Coating?** For Polylloy's ambient-cure grade, CorrosionGard-160S, the service limit is 160 °C (320 °F), with immersion service rated in its brochure. It cures at room temperature, so no start-up heat is needed, which suits structural steel, tanks and vessels. For hotter service, a heat-cured grade such as FlueGard-225SQC or StackGard-255SQW is selected instead. **Is There a Quick Cure Coating for a Short Baghouse Shutdown?** FlueGard-225SQC is a two-component Sprayable Quick Cure grade rated to 225 °C (437 °F) for baghouses, electrostatic precipitators and ducts. It goes on after a near-white blast and is heat-cure activated as the plant starts up. Whether it fits a given shutdown depends on area, access, blasting and humidity control, which Polylloy reviews per project. **How Long Does a Kiln Shell Coating Take to Apply?** There is no fixed figure: time on site depends on the shell area exposed, the refractory removal sequence, blasting, access, humidity control and inspection hold points. KilnGard-600SCW goes on as a single coat, which avoids the return visits of multi-coat systems. Polylloy and the application partner fit the work inside the planned reline schedule. **What Are the KilnGard-600SCW Application and Cure Requirements?** KilnGard-600SCW needs an SSPC-SP10 near-white blast with a profile over 3 mils (75 µm), a steel surface between 10 and 50 °C, humidity below 90 % and the steel 5 °C above the dew point. It is applied as a single coat of 15 to 25 mils. Final heat cured activation is completed during start-up using process heat. **Can Process Flue Gas Be Used to Cure a Coating?** Yes, for Polylloy's heat-cured grades. Final heat cured activation is completed during start-up using process heat, so the hot gas or kiln heat of a normal start-up completes the cure. Where start-up heat cannot reach a coated area, Polylloy's technical team defines an alternative, and the cure energy route becomes part of the project cost. **What is a Heat Cured Coating and Why Does It Need Heat?** A heat-cured coating is applied at ambient temperature and then reaches its final properties when heated in service. For Polylloy grades, that heat activates the chemical bonding with the steel and the internal bonding of the coating itself. Every Polylloy grade with a published bulletin except CorrosionGard-160S is heat-cured, and the activation happens during plant start-up. **How is a Kiln Shell Coating Applied During a Shutdown?** With the refractory removed, a certified Polylloy partner blasts the shell to SSPC-SP10 and applies KilnGard-600SCW by air spray, roller or brush under Polylloy supervision. The partner then checks film thickness and repairs defects. The new refractory is installed over the coating, and activation is completed when the kiln starts up.