Hempel MultiCoat Primer And Topcoat Paint

Hempel’s Multicoat 51120 is a high-opacity, semi-gloss alkyd marine primer and topcoat for glass fibre, wood and steel. Designed for interior and exterior areas above the waterline, it can be used as a complete coating system and provides good resistance to sunlight, water and oil. Its theoretical coverage is 11m² per litre at the recommended 40-micron dry film thickness.

Hempel’s Multicoat combines the functions of a primer and finishing coat, reducing the number of separate products required for suitable above-waterline projects. It can be used on correctly prepared external and internal marine surfaces, including deck structures, lockers and dry bilge areas that are not subject to permanent immersion. For walked-on deck surfaces, a suitable anti-slip additive or dedicated non-slip coating system is required.

All surfaces must be clean, dry and free from oil, grease and other contaminants. Bare glass fibre, wood and steel should be prepared according to Hempel’s applicable primer instructions. Previously painted surfaces must be abraded, cleaned and dried before recoating. Where a separate undercoat is required, Hempel lists Hempel’s Primer Undercoat as the recommended previous coat.

When using Multicoat as a primer, apply the first coat thinned by no more than 10% with the specified Hempel thinner. For use as a topcoat, apply two to three coats. Sanding between coats and complete dust removal are recommended where a smoother finish is required.

Apply by brush, roller or paint pad, with thinning limited to a maximum of 5% for normal topcoat application. Use Hempel’s Thinner 811 (No. 1), product code 08111, for brush, roller and paint-pad application. Hempel’s Thinner 808 (No. 3), product code 08081, is the spray thinner for Hempel one-component topcoats; contact Hempel for Multicoat spray-application parameters.

At 20°C, Hempel’s Multicoat is touch dry in approximately three hours and ready to sand after 24 hours. The normal overcoating interval at 20°C is eight to 72 hours. Maintain adequate ventilation during application and drying, and keep relative humidity below 85%.

Key Features

• High-opacity marine primer and topcoat
• Official Hempel product code 51120
• Alkyd paint formulation
• Semi-gloss finish
• Can be used as a complete coating system
• Suitable for glass fibre, wood and steel
• For interior and exterior use above the waterline
• Good resistance to sunlight, water and oil
• Standard shade White 10000
• Theoretical coverage of 11m² per litre
• Recommended dry film thickness of 40 microns
• Recommended wet film thickness of 87 microns
• Apply by brush, roller or paint pad
• Spray application possible with guidance from Hempel
• Use Hempel’s Thinner 811 for brush, roller or paint-pad application
• Use Hempel’s Thinner 808 as the spray thinner
• Maximum normal topcoat thinning of 5%
• Maximum first-coat thinning of 10% when used as a primer
• Apply two to three coats when used as a topcoat
• Sanding between coats recommended for a smoother finish
• Touch dry in approximately three hours at 20°C
• Ready to sand after approximately 24 hours at 20°C
• Overcoating interval of eight to 72 hours at 20°C
• Relative humidity must remain below 85% during drying and curing
• Surface temperature must be at least 3°C above the dew point
• Shelf life of 60 months at 25°C in unopened containers

Frequently Asked Questions

What is Hempel’s Multicoat 51120 used for?
It is used as a combined primer and semi-gloss topcoat on glass fibre, wood and steel. It is intended for interior and exterior marine surfaces above the waterline.

Can Hempel’s Multicoat be used as both a primer and topcoat?
Yes. Hempel states that it can be used as a complete coating system. When it is used as the primer, the first coat may be thinned by up to 10%. Apply two to three coats when using it as a topcoat.

Which surfaces are compatible with Hempel’s Multicoat?
It is suitable for correctly prepared glass fibre, wood and steel. Bare substrates must be prepared in accordance with Hempel’s relevant primer instructions.

Can it be applied directly to bare wood?
Bare wood must first be prepared according to Hempel’s primer instructions. On a suitably prepared substrate, the first Multicoat coat may be used as the primer coat and thinned by no more than 10%.

Can Hempel’s Multicoat be used below the waterline?
No. It is specified for interior and exterior use above the waterline and should not be used as a permanently immersed coating.

How many coats should be applied?
When used as a topcoat, Hempel specifies two to three coats. The first coat may be thinned by up to 10% when the product is being used as a primer.

How much area does one litre cover?
The current theoretical spreading rate is 11m² per litre at a recommended dry film thickness of 40 microns. Actual coverage will vary according to the surface profile, application method and coating losses.

Which thinner should be used for brush or roller application?
Use Hempel’s Thinner 811 (No. 1), product code 08111. It is a thinner and tool cleaner for Hempel one-component primers, topcoats and varnishes.

Which thinner should be used for spray application?
Use Hempel’s Thinner 808 (No. 3), product code 08081. It is Hempel’s spray thinner and tool cleaner for one-component topcoats. Multicoat spray parameters should be confirmed with Hempel before application.

How long does Hempel’s Multicoat take to dry?
It is touch dry in approximately six hours at 10°C or three hours at 20°C. At 20°C, it is ready to sand after approximately 24 hours.

What is the overcoating interval?
At 20°C, the minimum overcoating interval is eight hours and the maximum is 72 hours. At 10°C, the interval is 16 hours to five and a half days. If the maximum interval is exceeded, roughen the surface before recoating.

Can Hempel’s Multicoat be used on decks?
It may be used as an above-waterline coating, but a smooth semi-gloss coating alone is not suitable where slip resistance is required. Use a suitable anti-slip additive or dedicated non-slip coating system on walked-on areas.

Does its oil resistance mean spills can be left on the surface?
No. Petrol, diesel, oil and acetone spills should not be allowed to pool because their solvents can damage the coating. Remove spills using a suitable boat shampoo.