When painting steel water tanks, consider two points: steel is subject to rust and ill-suited for paint. These two factors complicate the painting process. Professionals know the proper ways to combat these two issues. If you want the finish on your water tank to last, coat the steel with a base, formulated with acidic properties. This acid base will allow the primer to etch the steel, resulting in a strong bond that will last and last. Be sure the acidic primer you choose has rust-inhibitive properties, or oxidation may follow.
- Skill level:
Things you need
- Water-based degreaser cleanser
- Steel wool
- Water hose
- Painter's tape
- Fabric dust sheets
- Rust-inhibiting galvanised metal etching primer
- Polyester paintbrush
- Acrylic enamel
Clean the steel water tank with a water-based soap that has degreasing properties. Use steel wool to scrub potential unseen oils and grease. Rinse exterior water tanks, using a hose. Rinse interior tanks with wet rags.
Attach tape to parts of the tank that are to remain unpainted. Ordinary masking tape may prove unreliable. Choose a low-tack painter's tape to ensure adequate protection.
Position dust sheets underneath the water tank. Fabric dust sheets are best suited for exterior steel tanks, because they won't blow loose in the wind.
Cleaning & Prep
Coat the steel water tank with etching primer, using a paintbrush. While any synthetic brush will work, some may leave noticeable marks in the finish. Promote a neat painted finish by using a polyester brush. Apply vertically strokes and watch carefully for runs. Allow the tank to dry for three hours.
Wash your brush in a sink, or using a water hose.
Paint the steel water tank as you primed it. Although latex paint works fine, acrylic enamel is more durable. Allow the tank to dry for two hours. Add a second coat if the finish dries unevenly.
Priming & Painting
Tips and warnings
- Use a roller to finish large water tanks.
- If you prime a steel water tank using a latex or oil primer, chipping will follow.