While galvanisation protects steel from corrosion, the surface still requires painting for extra protection and aesthetic purposes. Painting galvanised steel is a fairly simple task as long as you know the right products to use and the best application procedures.
1) Surface Pre-Treatment
As with any other painting project, surface preparation is more than half of the job. Ideally, the steel should be painted right after galvanisation before it’s contaminated by dirt, oil or grease. If the surface has been exposed to the elements, it’s important to clean them off thoroughly.
T-wash is considered the most effective way to clean galvanised steel before painting. When applying T-wash, it’s important to avoid it pooling on the surface since it may keep the paint from sticking. All excess T-wash must be removed with clean water.
T-wash is suitable for all types of galvanised steel unless it’s weathered. Once you apply T-wash, you need to leave it on the surface for some time to allow a reaction to take place. Then the solution should dry fully. When T-wash starts working, the galvanised surface turns black.
Each T-wash manufacturer will specify the curing time on the box. If you don’t see any recommendations, contact the provider. After the recommended time is up, wash the surface with clean water. If any salt is left on the surface, remove it with a stiff brush.
2) Apply A Primer
Once the steel is clean and dry, you can start applying a primer. Make sure you choose the right primer for galvanised steel by consulting the provider. Follow the instructions for mixing, if applicable.
Different types of primers are suited for different projects. Most primers can be applied by brush, roller or spray. Allow the primer to dry fully according to the manufacturer’s recommendation. Don’t rush to paint the surface after applying the primer. You may face adhesion problems when painting over a wet primer. Always follow manufactures recommendation for over coating times.
3) Paint The Steel
Only use paint suitable for a galvanised steel surface, or you may face problems with adhesion. The type of paint you choose depends on the environment around the steel. The most popular products are high-build epoxy and vinyl. Other choices are two-pack polyurethane and acrylic urethanes. Consult the paint provider to choose the best product for your purposes.
Ideally, the paint you buy should be the same brand as the primer. The application process is similar as well. Always read the directions and allow the paint to dry fully before using the application.
Find Out More
At TA Paints, we offer all the products you need to complete your galvanised steel painting projects. Browse our online store and order products today.
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