How Do I Paint Galvanised Steel?
Galvanisation or galvanising is the process of applying a protective zinc coating to steel or iron, to prevent rusting.
The problem with painting galvanised metal is that the surface when new is very shiny and smooth, making it difficult for paint to stick to the surface. It also has surface contaminants (oils, greases, residues, etc.) left on the surface from the manufacturing process that interfere with the adhesion of paints. You need to tackle this with the right products and preparation to make sure it stays put. You’ll notice on surfaces that haven’t been treated properly, that the paint will peel and blister very quickly.
Priming and Preparation
If you want to paint a galvanised surface, you need to prepare it properly with thorough cleaning and a good primer where required.
New Surfaces:
Thoroughly wash with an alkaline cleaning solution using a Scotch-Brite pad to scrub the surface. Once cleaned, thoroughly rinse down with fresh water and allow to dry. Now you’re ready to prime with one of Tikkurila's suitable primers:
- Rostex Super Akva
- Rostex Super Metal Primer
- Otex Adhesion Primer
- Temaprime EE (for professional use only)
- Temadur 10 or Temadur 20 (for professional use only)
Weathered Galvanised Surfaces (12 months +)
If the galvanised metal you’re intending to paint has been left out in the elements for 12 months or more then the tricky cleaning process of removing all the manufacturing contaminants has been carried out for you. All you need to do is clean any dirt and grime that has built up on the surface and apply one of the aforementioned primers
Previously Painted Galvanised Surfaces
You’ll want to remove any old flaky paint with a non-metallic abrasive (sandpaper) and wash down as you would with newly galvanised surfaces (see above). Once it’s ready, you should apply one of the aforementioned primers to any bare galvanised surfaces.
Painting and Decoration
Once you’ve prepared your surface and primed it if required, you are ready to apply a topcoat. The selection of topcoat will depend on the ultimate use. Suitable topcoats from the decorative range include:
- Everal Aqua 10, Everal Aqua 40 or Everal Aqua 80, depending on the sheen level required
- Panssari Akva
- Panssarimaali
If your project is more industrial in its nature, we recommend looking at products from our industrial range which include:
- Temalac FD20, Temalac FD50 or Temalac FD80, our range of single pack alkyds.
- Temadur 10, Temadur 20, Temadur 50 or Temadur 90, our range of 2 pack polyurethanes
If you require more advice on painting over galvanised steel, give our technical team a call on 0131 334 4999 or send a message to our technical team.
