International One UP Primer/Undercoat 0.75L

International One UP is designed for preparing yacht and boat surfaces before the application of compatible one-component finishes.

It can be applied to properly prepared GRP/fibreglass, wood, steel, aluminium, zinc/galvanised steel and epoxy surfaces, making it a versatile solution for topsides, superstructures and other areas above the waterline.

The formula is easy to apply by brush or roller and creates a smooth surface that can be sanded before the finishing coat. International developed One UP to replace the traditional Yacht Primer and Pre-Kote system while maintaining effective adhesion and substrate protection.

Depending on the substrate, International recommends 2 to 4 coats. GRP normally requires 2 coats, steel and aluminium 3 coats, and bare wood 4 coats when applied unthinned.

Available Colours

• White – YUC000 – 0.75L
• Blue Grey – YUC001 – 0.75L

Both colours can be selected according to the final topcoat colour and the required painting system.

Application

Apply One UP to a clean, dry and correctly prepared surface.

For previously painted surfaces in good condition, clean thoroughly and sand with approximately 220–280 grit abrasive paper. GRP and epoxy surfaces should normally be degreased and sanded with 180–220 grit before application. Preparation requirements differ for wood, steel, aluminium and galvanised steel, so the relevant International application instructions should always be followed.

Thinning is normally not required. If application conditions require it, One UP may be thinned by up to 10% using International Thinner No.1 or Thinner No.100. Thinning may require an additional coat to achieve the required film thickness.

Technical Details

• Brand: International
• Product: One UP
• Type: Single-pack primer / undercoat
• Pack Size: 0.75L
• Colours: White / Blue Grey
• White Code: YUC000
• Blue Grey Code: YUC001
• Application Area: Above the waterline
• Application Methods: Brush / Roller
• Recommended Coats: 2–4 depending on substrate
• Theoretical Coverage: 10 m²/L per coat
• Practical Coverage: 9 m²/L per coat
• Volume Solids: 48%
• Specific Gravity: approx. 1.43
• VOC: 256 g/L
• Recommended Dry Film Thickness: 48 μm per coat
• Recommended Wet Film Thickness: 100 μm per coat
• Application Temperature: 5°C–35°C
• Suitable Thinners: International Thinner No.1 / Thinner No.100
• Typical Shelf Life: 2 years

Typical Drying Times

At 25°C, One UP is approximately:

• Touch Dry: 2 hours
• Hard Dry: 3 hours
• Sandable: 12 hours

Drying and overcoating times vary according to temperature and application conditions.

Important: One UP is intended for areas above the waterline and is not suitable for permanently immersed surfaces. It should not be overcoated with two-component solvent-based products. Always follow the International technical data sheet for substrate preparation, application and overcoating intervals.