Rayson PrimeBond E25 is a two-component, medium-viscosity, solvent-free epoxy bonding primer for dry or damp substrates — formulated to wet out and anchor to highly absorbent concrete, screed, asphalt and prepared metal.
Best for priming porous, highly absorbent concrete and screeds — and asphalt or prepared metal — before Rayson resin floor systems, including in enclosed, unventilated areas.
PrimeBond E25 pairs a milky epoxy resin with an amber-brown hardener into a medium-viscosity, solvent-free primer built for absorbency: on thirsty concrete and screed it soaks in and seals the surface rather than sitting on top, giving the floor system above it the grip it depends on.
Carrying no solvent, it can be used where ventilation is limited, and it accepts dry or damp substrates alike — useful on ground-bearing slabs in Singapore’s humidity. On mechanically prepared concrete its bond outperforms the substrate: pull-off tests fail in the concrete, not at the primer line.
It primes new and existing concrete, cementitious screeds, sound existing epoxy floors, asphalt and mechanically prepared metal, and is overcoated with the specified Rayson body coat or finish.
A primer is the first coat. It seals and strengthens the surface and creates the bond the rest of the system relies on. It is not a wearing surface on its own.
The figures below are a guide for planning. Site conditions and workmanship affect results — confirm the details for your project with our technical team.
| Coverage | 6–8 m² per kg per coat, varying with substrate condition and porosity |
|---|---|
| Mixing | Two pre-weighed parts, mix ratio 4:1 (A:B) by weight; mix mechanically for at least 2–3 minutes; pot life up to 30 minutes at 30 °C |
| Drying & curing | Final cure 7 days |
| Pack sizes | Part A 4 kg / Part B 1 kg per set, or Part A 16 kg / Part B 4 kg per set |
It is formulated for highly absorbent concrete and cementitious screeds, where its medium viscosity lets it soak in and seal the surface. It also primes new and existing concrete, sound existing epoxy floors, asphalt and mechanically prepared metal.
Yes — it accepts dry or damp substrates, provided there is no standing water and substrate moisture stays at or below 5%. For wetter slabs or active moisture ingress, speak to our technical team first.
The two pre-weighed parts mix at 4:1 (A:B) by weight, stirred mechanically for 2–3 minutes. Pot life is up to 30 minutes at 30 °C, and mixed material cures faster in hot weather and in larger batches.
Both are solvent-free epoxy bonding primers usable in unventilated areas, with coverage around 6–8 m² per kg per coat. E25 mixes 4:1 by weight and is aimed at highly absorbent substrates; E20 mixes 2:1.
Yes — being solvent-free, it is stated as suitable for unventilated areas. Standard PPE and good working practice still apply; consult the SDS once available.
Rayson PrimeBond E20 is a two-component, medium-viscosity, solvent-free epoxy bonding primer that anchors resin floor systems to concrete, screed, asphalt and prepared metal — on dry or damp substrates.
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Rayson PrimeBond S30 is a two-part, low-viscosity, solvent-based epoxy primer that penetrates and seals prepared concrete, pavements and mineral substrates before coating.
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Rayson PrimeBond W10 is a one-component, water-based acrylic primer, sealer and bonding agent for smooth concrete and mineral substrates, applied ahead of Rayson UraForce water-based topcoats.
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Answers from Rayson's own product information
Guidance only — confirm specifications with the Rayson technical team.