Write the chemical service brief before naming a coating

“Chemical resistant” is not a specification. Obtain the current safety data sheet and describe every liquid that may contact the lining: its identity, mixture composition, concentration range and contaminants. Record normal and peak temperature, whether the liquid is stagnant or flowing, expected contact duration, cleaning regime, pressure or hydrostatic head, and whether the asset is a primary tank, transfer pit or secondary bund. An acid at ambient temperature and the same acid in a heated process can be different lining duties. A bund expected to hold a rare spill still needs compatible materials and an agreed time to detect and remove that spill.

Record abnormal conditions too: a process upset, hot wash, emptying cycle, vapour zone or a second product stored after changeover. Do not infer resistance to a mixture from a list of individual ingredients. ALKA should review this service brief against the current technical data and available chemical-resistance evidence before confirming a lining and cure period.

Choose the lining family by its actual duty

The ALKA-9936 system page describes ALKA Tanklin 100 and Tanklin Chem as selection options. The current tank-linings product family uses the spelling “TankLine”. Confirm the current product identity and sheet with ALKA before quoting, ordering or specifying. Neither the family name nor a generic novolac label is proof of fitness for a particular acid, solvent or fuel.

Design for the substrate and the weak details

Steel tanks and vessels

Inspect fabrication before abrasive preparation. Weld spatter, sharp edges, crevices, porous welds, threaded attachments and inaccessible backs of nozzles create thin-film areas or trap liquid. Repair details and agree edge treatment before the lining contractor starts. The specification should set surface cleanliness and profile, allowable soluble contamination, environmental conditions and hold points. AMPP SP0178 addresses design, fabrication and surface finish of tanks and vessels intended for immersion linings; the coating supplier and project engineer must translate it into the asset-specific work package.

Concrete bunds, pits and sumps

Investigate whether the concrete is sound and dry enough for the selected system. Laitance, old sealers, oils and chemically damaged concrete must be removed. Profile the surface by a method suitable for the chosen lining, then repair blowholes and honeycombing so liquid cannot track behind the film. Document joints, movement, floor-to-wall junctions, penetrations and drains. A rigid film bridging an active structural joint is vulnerable; the joint needs an engineered detail compatible with both expected movement and chemical service. Negative-side moisture or hydrostatic pressure needs a separate assessment. ICRI 310.2R provides a framework for specifying concrete surface preparation for coatings and overlays.

For a bund, the coating is only one part of containment. Capacity, floor falls, drain isolation, spill removal procedure and the integrity of walls and penetrations matter. NSW EPA guidance describes bunds as structures to contain spills and leaks and facilitate clean-up; it calls for containment appropriate to the liquid and amount stored. Have the facility designer verify applicable storage and environmental requirements separately from the coating schedule.

Make application and acceptance measurable

1. Approve a written schedule. Identify preparation, repairs, primer where required, lining grade, mixing, coat count, stripe coats, wet and dry film checks, recoat window and full cure before filling. Film build is project-specific; do not copy a thickness from a different service.
2. Set hold points. Record substrate cleanliness, profile, moisture and environmental readings before coating. Inspect corners, welds and penetrations after detail coats and again after the body coats.
3. Verify continuity. Inspect for pinholes, voids, runs and damage; perform discontinuity or “holiday” testing when the substrate, film and project specification permit it. AMPP SP0188 covers testing of new coatings on conductive substrates; test method and voltage must suit the actual system.
4. Release only after cure. Preserve batch, mixing and inspection records, repair defects, reinspect and obtain the specified cure confirmation before introducing the process liquid.

No lining restores a structurally failed tank or makes a leaking concrete construction joint sound by itself. Where chemicals could reach soil, drains or occupied spaces, treat design, repair, installation and inspection as a single containment package.

Frequently asked questions

Is an epoxy floor coating suitable inside a chemical tank?

Its floor use does not establish immersion suitability. Ask for written compatibility with the exact chemical, temperature and exposure cycle, plus a tank lining schedule and inspection plan.

Can one lining cover every chemical in a bund?

Only if the selected build is separately confirmed for each credible spill, including mixtures and cleaning chemicals. Separate bund zones may be needed when service conditions conflict.

Does more coating thickness compensate for a pinhole?

No. Thickness and continuity are separate controls. A local holiday can expose the substrate despite a high average film build.