Overview

A clear coat sits on top of everything else you have already paid for. If it yellows, the floor underneath yellows with it, and on a flake floor or a bluestone path that is the whole job gone.

Bettathane PU-244 is a moisture cure polyurethane, clear and high gloss, and Chemstuk lists it as non yellowing. It holds its clarity outdoors rather than going amber after a summer or two. Single pack, so no hardener, no ratio and no clock running while a mixed bucket goes off.

Key Features

• Single pack, moisture cure polyurethane
• Clear gloss finish that does not yellow
• Bonds strongly and resists water, oil and grease
• Works indoors and outdoors, including over bluestone and exposed aggregate
• Applied by roller or brush only

Specifications

• Type: single pack, moisture cure
• Solids by volume: 65 plus or minus 0.5 percent
• Coverage: 8 to 10 square metres per litre per coat
• Coats: two, which works out to roughly 16 to 20 square metres from a 4 litre tin and 60 to 75 square metres from 15 litres of finished floor
• Recoat: 7 to 72 hours
• Foot traffic: 24 hours. Full cure: 7 days
• Relative humidity for curing: 30 to 60 percent
• VOC: maximum 350 g per litre. Flash point: 32 degrees Celsius
• Clean up: xylene

Applications

• Wear coat over epoxy flake systems
• Bluestone, pavements and exposed aggregate
• Residential, commercial and industrial floors
• Timber and metal where a hard clear finish is wanted

It Cures On Humidity, Not On Time

Bettathane pulls moisture out of the air to cure, which makes it easy to use and also makes the weather part of the job. Between 30 and 60 percent relative humidity it behaves. Below 30 it slows right down. Above 60 it cures too fast and you can get bubbling or a milky cast in the film. Check the humidity before you start.

Roller Or Brush Only

This is not a preference. Chemstuk states the product is approved for roller and brush application only, because spraying a moisture cure polyurethane generates respirable isocyanate aerosol and cartridge respirators do not protect against it. Once a tin is opened the whole contents should be used, because the product cures on contact with atmospheric moisture.

What You Need to Complete the Job

Over a flake floor, abrade lightly, vacuum and solvent wipe before the clear coat goes on, and order your Color Chips and Indopox E6-133 basecoat at the same time. A gloss clear coat is smooth by design, so on a ramp, a wet area or an outdoor walkway stir Grip-PE 711 into the final coat and back roll to keep the spread even. The full range is in Concrete Coatings.

Frequently Asked Questions

How many coats does it need?

Two. Chemstuk quotes 8 to 10 square metres per litre per coat, so a 4 litre tin finishes roughly 16 to 20 square metres and a 15 litre pack roughly 60 to 75.

Can I do three coats?

Yes, on a heavily trafficked or porous floor. The second coat has to be dry through first, not just touch dry, or the layers separate and the top one lifts weeks later.

What happens if I miss the recoat window?

Past 72 hours the first coat has hardened off and the second one only sits on top of it. The floor then has to be sanded back to a matt before you continue.

Can it go over bluestone?

Yes. Clean back to bare stone and let it dry through first. Bluestone holds water for longer than it looks like it does.