Quick answer: The right primer depends on the substrate, not the topcoat. For new plaster use Solvent Based Plaster Primer; for bare metal use ZP4 Anti Rust Primer; for wood use the matched wood primer; for damp or porous surfaces use a bonding agent like Bond and Key.
Picking the wrong primer is the most common reason paint jobs fail within 2–3 years in SA conditions. Here's a substrate-by-substrate guide to the Rhinoluxe primer range.
Why primer matters
A primer does three things: seals the substrate so the topcoat can't be absorbed unevenly, creates a bonded layer the topcoat can grip, and (depending on substrate) neutralises specific threats like rust on metal or alkalinity in new plaster. Skip the primer and you get peeling, blotchy coverage, and topcoat failure.
Primer by substrate
| Substrate | Use | Why |
|---|---|---|
| New plaster (curing) | Solvent Based Plaster Primer | Neutralises alkalinity; deep penetration |
| Cured plaster (recoat) | Water Based Plaster Primer | Low VOC, fast dry, environmentally friendlier |
| Bare steel / iron | ZP4 Anti Rust Primer | Rust neutraliser + primer in one |
| Coastal steel (sustained exposure) | Zinc Phosphate Primer | Maximum corrosion resistance for salt-air zones |
| Galvanised metal / etch | Etch Primer | Bonds to non-ferrous metals |
| Water-based steel | Steel Primer | Low VOC alternative for steel |
| Concrete (porous, dusty) | Clear Bonding Liquid | Seals friable surfaces, improves topcoat adhesion |
| Damp / problematic walls | Bond and Key | Bonds where standard primers can't grip |
| Repaint over old paint (sound) | Universal Undercoat | Bonds new to old, covers minor staining |
| Wood (interior + exterior) | Red Oxide Primer or Pink Wood Primer | Seals timber, blocks tannin bleed |
Common primer mistakes
- Universal undercoat on bare metal — won't stop rust. Use a metal-specific primer.
- Skipping primer on cured concrete — paint absorbs unevenly into porous patches. Use Clear Bonding Liquid first.
- Water-based primer over fresh damp — won't dry properly. Fix the damp first, or use a damp-tolerant primer.
Need help?
If you're not sure which primer fits your substrate, our team at the Table View or Edenvale paint shops can advise. Bring a sample or a photo. See the full Rhinoluxe primer range online or call +27 84 985 6141.
