RomoCoat Two Pack Etch Primer
RomoCoat Two Pack Etch Primer is a two‑component, self‑etching primer that chemically bites into metal and gives excellent adhesion on galvanised iron, aluminium and other non‑ferrous metals, and also improves adhesion/corrosion resistance on steel.
Product description
- Two‑pack air‑drying etch / wash primer based on special resins and acidic components, designed to etch the metal surface and create a thin, tightly adherent conversion layer.
- Provides strong adhesion for subsequent primers and topcoats, especially on difficult metals where normal primers tend to peel or flake (GI, aluminium, light alloys, pre‑coated sheets).
Typical applications
Adhesion promotion on non‑ferrous metals
- Galvanised iron sheets, purlins, guard rails, cable trays, ducts, roofing sheets and metal sprayed steel where adhesion is normally poor.
- Aluminium: panels, doors/windows, cladding, tanks, housings, light alloys and extrusions.
- Other non‑ferrous: zinc, copper, brass and tin components where a thin etching primer is required before main primer/topcoat.
On ferrous metals
- Bare steel or thin sheet metal that cannot easily be blast‑cleaned; etch primer plus hand/power‑tool abrasion gives enough key for subsequent primers/finishes.
- As a first coat in high‑humidity/monsoon conditions to reduce flash rust and improve adhesion of full paint systems.
Important: Etch primers are very thin and give only limited corrosion resistance by themselves; they must be overcoated with a suitable primer or build coat for long‑term protection.
Product Data Sheet
| Property | Details |
|---|---|
| Type | Single-pack, air-drying light phosphating coating. |
| Finish | Slight / light shining |
| Colour | Blue (other colours on request). |
| Volume solids | Approx. 7%. |
| Recommended DFT/coat | 5–10 microns. |
| Theoretical spreading rate | 14.0–7.0 m²/L at 5–10 µm DFT. |
| Surface dry | 10–15 minutes (typical fast‑dry etch). |
| Hard dry | about 1 hour at 30°C, or can be stoved at 100°C for 5 minutes for faster handling. |
| Overcoating interval | minimum 4–8 hours |
| Flash point | Above 23 °C. |
| Thinner | Normally not required (supplied ready for use). |
Surface Preparation
- All surfaces must be dry and free from oil, grease, salts, dust and other contaminants; degrease with suitable solvent/cleaner where necessary.
- Galvanised / aluminium / non‑ferrous: Lightly abrade or scuff with Scotch‑Brite / fine abrasive where possible to remove passivation layers/oxide and to assist the chemical etch.
- Steel / ferrous: Ideally blast‑clean to Sa 2–Sa 2½, but where blasting is not possible, thorough hand/power‑tool cleaning (St 2/St 3) to sound bare metal is acceptable.
Application guidance
- Mix base and activator strictly as per your internal mix ratio (not given in your text, so state on label, e.g. 1:1 or 4:1) and stir thoroughly until homogeneous.
- Apply very thin, even coat; do not exceed recommended DFT (5–10 µm). Thick films reduce etching action and can crack.
- Allow to dry for the specified minimum interval before applying the next coat (alkyd, epoxy, PU, chlorinated rubber, vinyl etc. – as per your compatibility list).
Typical system examples
- GI / aluminium exterior: 1 x RomoCoat Two Pack Etch Primer (5–10 µm) → 1 x epoxy or zinc‑phosphate primer (30–40 µm) → 1–2 x PU or alkyd topcoat.
- Steel in monsoon/high humidity (where blasting difficult): Hand/power‑tool clean → 1 x etch primer → 1 x anti‑corrosive primer → finish coat (alkyd / epoxy / PU).
Health & Safety
- Avoid inhalation of solvent vapour and paint mist and avoid contact with skin and eyes; use gloves, goggles and appropriate respirator according to local regulations.
- Provide good / forced ventilation in confined or poorly ventilated spaces.
- Etch primers contain acidic components; follow SDS for handling, first aid and disposal and keep away from alkali‑sensitive substrates not intended for treatment.