Product Description
Mordant solution is a T wash galvanised steel metal wash that contains a reactive chemical solution used to as a pre-treatment for galvanised surfaces which turns black and aids the adhesion of future coats of paint. Supplied as a blue solution that has a characteristic blackening effect on the galvanised surface. This helps in indicating that the treatment has been effective.
- Formulated to a British Rail T wash mordant solution galvanised steel specification
- Mordant solution is an excellent metal wash mordant solution for the pre-treatment and turn black galvanised steel and zintec sheeting prior to painting
- Once treated, you can apply a wide range of paints to the surface.
Not sure which whether to use mordant solution or etching primer? Take a look at our Blog here
We are proud to be a member of the British Coatings Federation.
Surface Preparation
To get the best results, clean down using an abrasive pad, water and cleaning agent
followed by rinsing and allowing to dry. Ensure surfaces to be painted are sound, clean
and dry (new surfaces particularly must be fully dry) and free from all defective or
poorly adhering material such as dirt, grease and oil. Universal degrease where
necessary with a suitable oil and grease remover. Rinse with clean water to remove
residues.
Mixing
Shake the solution in the container for approx 30 seconds ensuring the cap is tightly fastened.
Application
Can be applied by brush to weathered galvanised surfaces although reactivity of the treatment will diminish as the age of the galvanising increases and can result in an uneven colouration from light grey to dark grey. If no colour change take place, these areas should be considered as contaminated. Leave on the surface for about 15 minutes – 1 hour then rinse with clean water to remove acid residues.
Subsequent Coat
The pre-treated surface should be overcoated with an appropriate metal primer
within 48 hours or before contamination can recur
Application Methods
Brush
Q: What is Mordant Solution (T-Wash)?
A: Mordant Solution, often referred to as T-Wash, is a reactive chemical pre-treatment for new galvanised steel and Zintec sheeting. It is designed to change the surface of the metal to ensure that subsequent coats of paint adhere properly.
Q: How do I know if the Mordant Solution has worked?
A: The solution is blue in the bottle, but when applied to a clean galvanised surface, it should turn the metal black. This blackening effect is a clear indicator that the chemical reaction has taken place and the surface is ready for painting.
Q: What does it mean if the metal doesn’t turn black?
A: If no colour change occurs, it usually means the surface is contaminated (often with oil, grease, or a factory-applied passivator). These areas must be cleaned or degreased more thoroughly and re-treated.
Q: Can it be used on old, weathered galvanised steel?
A: It can be used, but the reactivity of the solution decreases as the galvanising ages. Weathered surfaces may show an uneven colour change ranging from light to dark grey rather than solid black.
Q: Is it better than an etching primer?
A: T-Wash is a traditional chemical pre-treatment specifically for galvanising. While etching primers are also used for adhesion, T-Wash provides a visible reaction that confirms the surface is ready. (Palatine also offers a blog comparison for further details).
Owen Davies –
Providing you take real care, as the label suggests, to degrease the surface, this works outstandingly well and better than an aerosol product I had previously purchased from a nationwide auto parts store!
David Ritchie (verified owner) –
It at first appeared to be an unnecessary extra cost and processes. However, having previously experienced paint blistering reactions having painted directly onto what I thought were well seasoned galvanized surfaces even using the recommended primer undercoat and process.
Applied this around 5 months ago in a 3 stage Mordant, Primer then Topcoat process and is looking good against a comparable now blistering primer/ topcoat without Mordant solution.
Its a major costly job trying to sort out paint problems. Fortunately for me this time its only on a small comparison test area this time.