Coo-Var Water-Based Primer Sealer Undercoat | Acrylic Primer Sealer

• Surface Prep: Clean surfaces, removing dust or loose material; repair cracks or holes as needed.
• Application: Stir well. Apply evenly with a brush—avoid overloading or pooling.
• Drying/Curing: Wait ~6 hours before applying your chosen topcoat; follow datasheet for complete details.
• Maintenance: Store any leftover primer in a cool, dry place; reseal tightly.
• Pro Tip: For best results on previously painted or glossy surfaces, lightly sand before priming.

Need a step-by-step guide? Our experts are standing by—chat live now!

Fast, Reliable & Fully Tracked UK Delivery

Every order is dispatched from our warehouse using a fully tracked DX or FedEx service, so you always know when your paint will arrive.

Delivery Options

• FREE Standard Delivery (orders over £75) Arrives in 2–3 working days
• Standard Delivery – £7.95 Arrives in 2–3 working days
• Express Delivery – £13.95 Next working day delivery when you order before 12:00 noon (Mon–Thu)
• Spending £75+? Select Express Upgrade at checkout and only pay the difference

Dispatch & Delivery Times (What Happens After You Order)

• Express delivery (order before 12:00 Mon–Thu) Dispatched same day, delivered next working day
• Standard delivery (Mon–Wed orders) Dispatched next working day, delivered 2–3 working days later
• Orders placed Thursday (standard delivery) Dispatched Friday for Monday delivery
• We do not dispatch or deliver on weekends or UK bank holidays

What to Expect on Delivery

Please provide a contact telephone number at checkout. This allows the courier to share tracking updates or contact you if there are any delivery issues.

Most orders require a signature on delivery. If you may not be available during the day, we recommend delivery to a workplace, business address, or another location where someone can sign.

Outside the UK Mainland?

Delivery prices shown apply to UK Mainland only.

For the Highlands, Islands, Northern Ireland, or non-mainland addresses, please contact us for a quick personalised quote via live chat, by calling 01482 222 421, or emailing info@specialistpaintsonline.co.uk.

Bottom Line

Order today, get fast and reliable delivery, track every step, and get painting without delays.

Free Delivery on Orders Over £75: Stock up on everything you need in one go

• Application Tools: Brushes, rollers, extension poles for easy, streak-free coverage
• Surface Cleaners: Remove grease or dust for improved paint adhesion

Ready to complete your kit? Chat with us for recommended extras!

Coo-Var Water-Based Primer Sealer Undercoat evens out porous plaster, wood and masonry so your finish coat glides on evenly and covers in fewer litres. By stopping paint sink in and blocking light stains, it slashes material spend, speeds turnaround and keeps customers smiling. Backed by over 100 years of British paint innovation, it’s arguably the best acrylic primer sealer money can buy. Its fast dry, low VOC formula lets you prime whole rooms before lunch while solvent rivals are still off gassing.

Key Benefits

• Seal Porous Surfaces – Locks down fresh plaster and bare timber to prevent paint soak in, cutting top coat consumption and saving cash.
• Prime New Plaster – Goes straight onto plaster, accelerating project schedules and getting spaces back in use sooner.
• Cost Effective Coverage – High 13 m²/L spread rates mean fewer tins on large jobs, protecting your profit margin.
• Multi Surface Solution – Clings to wood, masonry, PVC and more, so one primer handles the entire interior or exterior scheme, saving you cost and miniomising waste.
• Low Odour, Low VOC – Water clean up and low VOC keep indoor air fresh and crews comfortable all day, paint where others can't.
  

DIY friendly, R

• Finish / Texture: Matt
• Base: Water-based acrylic
• Available Colours: White
• Pack Sizes: 0.5 L, 1 L, 2.5 L, 5 L
• Coverage: 13 m²/L @ 35 µm DFT
• Drying Times @ 20 °C: Touch dry 30 min; hard dry 2 h; full cure 5–7 days
• Re-coat Interval: 6 h
• Minimum Application Temp.: 7 °C
• VOC Content: ≤ 30 g/L
• Flash Point: Non-flammable
• Application Method: Brush or roller; thin up to 10 % with clean water; clean tools with water
• Surface Suitability: New or painted plaster, wood, masonry, PVC, interior & exterior
• Volume Solids: 32 %
• DFT/WFT: 35–40 µm DFT; 75 µm WFT

Need detailed specs or prep guidance? Chat with our experts now!

Safety data sheet
Technical data sheet

1. What is Coo-Var Water-Based Primer Sealer Undercoat used for?

This primer is designed to create a smooth, even base on surfaces such as plaster, wood, and brick. It promotes excellent adhesion for topcoats, ensuring a flawless, durable finish.

2. How long does it take to dry?

The primer typically dries within 6 hours, making it convenient to apply your topcoat on the same day. Drying times may vary slightly depending on temperature and humidity.

3. Is it really low odour?

Yes, the water-based formulation emits minimal odour, which is especially helpful when working indoors or in poorly ventilated spaces.

4. Can I use it on previously painted surfaces?

Absolutely. As long as the existing paint is stable and clean, Coo-Var Water-Based Primer Sealer Undercoat can help improve adhesion and even out the surface before repainting.

5. How do I apply this primer?

Simply apply it with a brush to a clean, dry surface. Ensure any flaking paint or debris is removed beforehand. Once dry, you can proceed with your chosen topcoat.

6. Is it easy to clean up?

Yes, being water-based, you can clean brushes and tools with warm water—no need for harsh chemicals or solvents.

7. What coverage can I expect?

Coverage is approximately 13 m² per litre, depending on the substrate’s porosity and condition. Applying an even coat helps achieve the best result and maximises adhesion.

Need more advice on preparing your surface or choosing the right topcoat?

For personalised guidance or additional information, contact our experts now via live chat—we’re here to help you achieve a professional finish!