Chemical resistant paint provides protection from the harshest substances
Nearly all coatings will be exposed to chemicals at some point, whether cleaning products, spills, or fumes. However most of these are mild, and the coating does not need a special formula. A chemical resistant paint or coating is designed to provide protection from the harshest of substances. They need to perform safely and consistently under punishing conditions, and thus need to be highly resistant. Without a chemical resistant paint, substances such as solvents, acids, alkalis and salts can be absorbed by the substrate, causing contamination and deterioration.
Note that: The right chemical resistant paint is the one that satisfies the requirements of the substrate, as well as the needs of the chemical. Choosing correctly requires fully understanding both.
In this article the different chemical resistant coating options will be outlined, and we’ll provide a guide for choosing the right one as well as where to find products and specialists in Hong Kong.
5 things to take into account when choosing a chemical resistant paint
The range of substrates, chemicals and environments is matched by the range of chemical resistant paints. To choose the right chemical resistant paint you need to know a few things:
- The concentration of the chemical: the strength of the chemical will obviously affect the coating’s resistance.
- The temperature of the chemical: a heated chemical adds an extra factor for the coating to deal with.
- The type of chemical: each coating has different strengths, and may provide protection from one chemical but not another.
- The degree of exposure to the chemical: will the substrate be immersed, or is it just contact exposure?
- The duration of the exposure: how long will the coating need to withstand the chemical?
Substrates and environments which require heavy duty protection from chemicals include: flooring, pipelines, bunds, buried metal, storage or holding tanks, and concrete structures, treatment plants, laboratories, cooling towers, factories, machinery and equipment.
The 4 different chemical resistant paint options
Chemical resistant paint is available in a wide range of formulations, suitable for different applications. The main types of chemical resistant paint are epoxy, polyurethane, phenolic, and fluoropolymers. The choice of coating is further complicated by extra requirements such as high abrasion resistance, or sufficient lack of friction.
1. Fluoropolymer-based chemical resistant paint
Fluoropolymers are most known for being non stick coating (including Teflon and Xylan). However, fluoropolymers also provide very high chemical resistance at high temperatures. They can withstand a maximum use temperature of 300°C. Fluoropolymers are resistant to a wide range of chemicals, including concentrated sulphuric, hydrochloric, nitric and phosphoric acids.
Uses – Normally used where a low coefficient of friction or a lubricious surface is required. Suitable for use on concrete or metal in secondary containment linings, acid plants, fertiliser plants, oil refineries, and more.
Disadvantages – Fluoropolymers have poor weather protection characteristics, and cannot withstand acetic acid, acetone, esters and ketones.
2. Epoxy-based chemical resistant paint
Epoxy coating is the perfect coating for chemical resistance. They provide protection against practically everything; acids, alkalis, solvents, caustic fluids, fuels, fatty acids, salt or sugar solutions, chemical cleaning detergents and more.
Uses – An unprotected concrete floor can quickly deteriorate through exposure to chemicals, particularly flooring in the food and drink industry, plants, garages and factories. Having a floor that can withstand these exposures is important to prevent bacterial contamination. Epoxy coating is suitable for metals, concrete and wood.
Disadvantages – The disadvantage of epoxy coatings is that it tends to weaken with high or fluctuating temperatures, besides it is not as flexible as polyurethane. They are also not good with UV radiation (which causes it to chalk and fade), and can be stained by chemical attack.
3. Phenolic-based chemical resistant paint
These are the heavy duty chemical resistance paints. A phenolic coating is one where a phenolic resin is used to cure an epoxy (as in the case of a phenolic epoxy) or a novolac. They resist 98% sulphuric acid, hydrochloric acid, transmission fluid, gasoline, formaldehyde, phenol, and numerous other chemicals. Phenolic coatings perform better at higher temperatures than polyurethanes and epoxies.
Uses – Protective coating for tanks, ducts, piping, immersion service for most acids, solvents, and salts (chemical storage). Applicable for flooring in healthcare, science, technology and electronics industries, as well as chemical and waste treatment plants, pulp and paper mills, and power generation plants.
Disadvantages – Not recommended for exposure to some strong organic acids and solvents, and the less epoxy used in the makeup of the coating, the less resistant to chemicals it is.
4. Polyurethane-based chemical resistant paint
Polyurethane paint is resistant to organic caustic fluids, acids and alkalis, fuel and hydraulic oils, and solvents.
Uses – Where greater flexibility and an ability to deal with high temperatures is needed, polyurethane is the traditional alternative to epoxy. Polyurethane is also the preferred choice in the dairy industry where there is exposure to lactic acids.
Disadvantages – Polyurethanes coatings are softer than epoxy coatings, therefore they are more likely to abrade. Extremely sensitive to humidity at application. Less resistant than epoxies.
Chemical resistant coating products and specialists in Hong Kong
With so many different surfaces and environments that require chemical resistant paints, it is no surprise that the range of products and services is extensive. There are the coatings above, but there are also specially formulated coatings like methacrylate, which cures at low temperatures and is used for cold-store and freezer rooms. Below is a table outlining some of the available products for Hong Kong, with price indications. It is the coatings from reputable international coatings manufacturers like AkzoNobel that people trust.
|CHEMICAL RESISTANT PAINT TYPE||CHEMICAL RESISTANT COATING PRODUCT||PRODUCT SUITABILITY||PRICE FROM|
|Two component epoxy||Jotun Jotafloor Topcoat||Deal for industrial floors, laboratories, hospitals, food and beverage plants, kitchens, warehouses, factories, and manufacturing facilities.||710 HKD/5L at 10m2 per litre|
|Two component epoxy phenolic||International Interline 850||Tank and pipe lining for steel storage tanks and pipes containing a range of products including crude oil, gasoline, caustic solutions, potable water, and solvents.||7,625 HKD/ 20L at 6m2 per litre|
|Two component polyurethane topcoat||Rust-Oleum 9600 Rust-O-Thane Polyurethane||Heavy industrial and marine exposures, moist conditions and high abrasion and impact situations. Especially recommended for weather resistance.||2,070 HKD/5L at 13m2 per litre|
|Two component novolac vinyl ester||International Interline 955||Reinforced with glass flake to increase chemical and abrasion resistance. Intended for use in internal lining of chemical storage tanks and vessels for hot media (up to 90°C) or acids||9,260 HKD/20L at 2m2 per litre|
|Two component epoxy novolac||Sherwin-Williams Nova-Plate 325||For use on steel and masonry surfaces in industrial and marine environments such as oil storage tanks, secondary containment, ethanol storage tanks, and more.||2,615 HKD/5L at 2m2 per litre|
Finding a suitable applicator for your chemical resistant paint project
A chemical resistant paint should always be applied by a trained professional to ensure an effective and flawless application. If you have a project that needs a chemical resistant coating our experts are here to help! In cooperation with our partners we can provide you with a tailor-made quote, and connect you with the right coating solution. Just get in touch via e-mail or the “Request a quote” button at the bottom of this article.