Tech Tip : What Hardener &Thinner to use
Hardeners for paints are not all the same and cannot simply be mixed and matched. Hardeners for Selemix 2-pack Polyurethane and Acrylic topcoats are isocyanate-based. Those for Selemix Epoxy systems use amine-based hardeners; these react differently, and do not work in 2-pack polyurethane or 2-pack acrylic systems. Different hardeners not only have different solvents in them but also contain different active ingredients at different concentrations. If you are unsure of what hardener is suitable for which product make sure to check the Technical Data sheet, as this will contain the necessary information. Only the hardeners that are stated should be used at the specified mix ratios. If an incorrect hardener or mix ratio is used, the drying, hardness and durability will all be affected.
Thinners are of different types and different speeds of evaporation. Specific thinners are available for synthetic paints, nitrocellulose paints, 2-pack epoxy paints, 2-pack PU and acrylic paints. Again, these are not interchangeable and the use of the wrong thinner can cause bittiness in the paint. Make sure to always use the correct thinners specified on the Technical Datasheet. Gun wash and some cheap thinners often contain water and should never be used to thin paint!
In warmer conditions the temperatures rise, the solvents in the paint evaporate faster and can cause dry-spray and overspray issues. Many Selemix paint systems have slower thinner options which are more suitable for warmer weather. For 2-pack polyurethane and acrylic systems 1-208 Slow Thinner is recommended and 1-470 Slow Thinner is even slower. For 2-pack epoxy systems 1-400 Slow Thinner is recommended. These should be considered on warm days or when painting large areas.
For any advice please contact Simply Coatings Ltd for backup on the complete range, we are the main UK distributor for PPG Selemix paints.