Overview

Johnstone’s Trade Stormshield Aqua Guard Primer Undercoat is a high-performance, water-based undercoat specially formulated for exterior wood. It provides outstanding adhesion, excellent opacity, and blocks staining from bare timber by preventing resin bleed-through. Designed as the ideal foundation for Stormsheild Aqua Guard Gloss, Satin, and Matt topcoats, it ensures a uniform, long-lasting finish with superior durability for outdoor applications.

• Blocks resin bleed-through on bare timber
• Excellent adhesion to previously painted and porous surfaces
• High opacity for a smooth, even finish

Designed for use with Stormshield Aqua Guard Exterior Gloss or Satin

Preparation

Ensure the surface is clean, dry and free from dirt and grease.

• Remove any loose or flaking material
• For maximum performance from this microporous product, completely remove old paint and varnish. Treat any mould or lichen with sterilisation wash as directed. Treat bare wood surfaces with a suitable clear wood preservative.
• For bare timber, apply one coat of Johnstone's Trade Stormshield Aqua Guard Exterior Primer Undercoat followed by two coats of Johnstone's Trade Stormshield Aqua Guard Exterior Gloss or Satin.
• Prime bare metal with an appropriate metal primer.
• Rub down previously gloss painted surfaces with fine waterproof abrasive paper and rinse thoroughly before applying a pre-coat of Johnstone’s Trade Stormshield Aqua Guard Exterior Primer Undercoat.
• Uncoated plastic rainwater products should be cleaned thoroughly, primed with a single coat of Johnstone’s Trade Advanced Multi Surface Primer and given two coats of Johnstone’s Trade Stormshield Aqua Guard Exterior Satin or Gloss.

Application

Always test a small area of the surface to be painted to ensure you are happy with the finished results

• Stir thoroughly before use to ensure the paint is completely mixed.
• Stormshield Aqua Guard Exterior Primer Undercoat can be applied by brush, roller or sprayer. For best results use a synthetic brush. Avoid overspreading
• 2 coats are recommended on highly resinous surfaces.
• Sprayer application: HVLP application: 1.8-2.0mm tip size. Spray pressure: 0,3-0,4 MPa (= approx. 3-4 bar). Can be diluted 5-10% Airless spray application: 0.008"-0.010". 2000–2500psi. Undiluted. Must use Ultra Finish tips.
• Ensure good ventilation during application and drying.
• If using more than one can of the same colour, intermix prior to use to ensure colour consistency.
• Do not apply in temperatures below 8°C or externally when rain is imminent.
• Additional coats may be required with certain colours, or attempting a wide colour change.

Always follow manufacturer's instructions found on the tin

Note: To ensure the paint system achieves its life expectancy the product must be applied in accordance with a project specific Johnstone’s Trade Technical Specification and BS 6150:2019, Code of Practice for Painting Buildings.