Marindec PaintsThe difference is the liquid that carries the resin. Solvent-based paints use organic solvents that evaporate as the film forms. Water-based paints use water. That one difference changes how well the paint wets a surface, how it behaves in cold or damp weather, how it is cleaned up and how it must be stored.
Quick comparison
| Solvent-based | Water-based | |
|---|---|---|
| Typical Marindec products | Fast dry enamels, primers, 2K polyurethane, floor & stoep and road marking paint | Acrylic wall and roof paints, water-based etch primer (on request) |
| Best on | Steel and other metals, oily or hard-to-wet surfaces | Walls, masonry, wood and clean, absorbent surfaces |
| Thinning and clean-up | Matched thinner | Water |
| Odour and flammability | Strong odour; flammable. Ventilate and keep away from sparks | Low odour; not flammable in the tin |
| Watch out for | Over-thinning, recoating outside the window (wrinkling) | Cold surfaces, slow drying in damp weather, freezing in storage |
Why metal usually gets solvent-based paint
Steel rarely presents a perfectly clean surface. Traces of oil and the low surface energy of metal stop water-based coatings spreading properly. The surface examination guide uses a water-drop test: where water beads up, a solvent-based coating is needed. Metals generally fall in that range. Solvents wet these surfaces and carry the resin into the profile, which is why industrial primers and enamels for steel are solvent-based.
Solvent-based alkyds also dry fast. Marindec Fast Dry Enamel is touch dry in about 10 minutes and FPW15 primer can be overcoated within 2 hours, which suits production lines and dipping plants.
Where water-based makes sense
- Interior and exterior walls, plaster and masonry, where breathability and low odour matter
- Galvanised roof sheeting finished with an acrylic: the IBR sheeting guide allows a water-based or solvent-based acrylic over the right primer
- Occupied buildings, schools and hospitals, where solvent fumes are a problem
Conditions matter more than the label
Whichever you choose, the datasheet conditions apply: don't paint in rain, direct sun or humidity above 85%. Keep the surface at least 3°C above the dew point and work between 10°C and 35°C. Solvent-based coatings need good ventilation. Water-based coatings must not go onto cold surfaces.
Can you mix systems?
Only as the datasheets allow. A solvent-based topcoat over a water-based coat can soften or lift it, and strong thinners in an alkyd can cause wrinkling. Put a compatible primer between different systems, and check both datasheets or ask us before combining them.
Marindec manufactures solvent-based industrial coatings and water-based acrylics in Alberton, Gauteng. See the anticorrosive coating systems for steel, or request a quote.