Renner M641 Water-Based Primer - White
Spray finishing MDF has one recurring problem: cut edges and machined profiles drink primer and the fibres lift, so what went into the booth smooth comes back rough after the first coat. Renner YL-M641 is a water-based pigmented primer built to deal with that.
It's a white, high-build primer for wood and MDF — flat panels, frames, doors, skirting and furniture components — with high hiding and insulating power, fast drying, and good sanding properties, including on automatic sanding lines.
1K or 2K, your choice
This is the genuinely useful part. M641 works two ways from the same tin:
- Straight from the can (1K) for general work where the extra performance isn't needed.
- Catalysed with YC-M404 hardener at 2–10% for a substantially tougher, more durable film. Catalysing also reduces grain raising on MDF — which is why it's the usual specification for kitchen and bathroom furniture, where edges are handled and wiped constantly.
You add hardener only when the job warrants it, rather than stocking two separate primers.
Tinting
M641 takes Renner colourants. Bringing the primer close to the topcoat's base tone is worth doing on strong or dark colours — you reach full coverage and colour depth in fewer topcoat passes, which usually saves more than the tinting costs.
Notes
Water-based, so clean equipment immediately after use rather than at the end of the day.
Available in 5kg and 25kg. Hardener sold separately. If you're running M643 instead, note that it takes the M402 hardener — the two systems are not interchangeable.
Ireland & Northern Ireland — 1–3 working days. Charged by total order weight, VAT included:
- Up to 30 kg — €6.99, or free on orders over €85
- 30–60 kg — €13.99
- 60–100 kg — €27.99
- Over 100 kg — pallet delivery €49.99
Great Britain — 2–4 working days. €13.95 up to 30 kg, then €27.90, €55.90 and €99.90 by the same weight steps. There is no free delivery to Great Britain.
Rest of Europe — non-liquid items only, from €11.75, priced by destination and weight at checkout. Paint and other liquids ship to Ireland, Northern Ireland and Great Britain only.
Dispatch and collection — order before 12pm Monday to Friday and it ships the same day. Click & collect at Ballymount, Dublin 12 is free and often ready within the hour.
Returns — 14 days to change your mind and 14 more to send it back. Tinted paint is non-returnable once mixed.
