BETTATHANE PU-244 | Single Pack Polyurethane Sealer – 4L & 15L

Two things worth knowing

It cures on humidity, not on time.

Bettathane pulls moisture out of the air to cure. That makes it easy to use — nothing to mix — but it also means the weather decides how it behaves.

Between 30 and 60 percent relative humidity it cures the way it should. Below 30 it slows right down, and on a dry Melbourne day in January you can be waiting a lot longer than you planned. Above 60 it cures too fast, and you can get bubbling or a milky cast in the film as gas comes off faster than it can escape.

Check the humidity before you start, not after. A cheap hygrometer costs less than a tin of this and will tell you whether today is the day.

Seven hours before the second coat, and don’t leave it past three days.

You need seven hours before recoating — this isn’t a morning-and-lunchtime job. You’ve then got until 72 hours to get the second coat on.

Inside that window the coats bond into each other. Past it, the first coat has hardened off and the second one is only sitting on top of it, which means sanding the whole floor back to a matt before you can continue.

Going to three coats? Let the second one dry first.

Some jobs want more film than two coats give you — a heavily trafficked floor, or a porous surface where the first coat mostly disappeared into the substrate. Three coats is fine.

But the second coat has to be dry through before the third goes on. Not touch dry — dry. Put a third coat over a second one that’s still soft and the solvent in it gets into a film that hasn’t finished curing, and the layers separate. You don’t see it straight away. It shows up weeks later as the top layer lifting or peeling off the one underneath, usually in sheets.

Give the second coat three days at 25°C before the third, and longer if it’s colder or the humidity is at the low end of the range.

Then test before you commit. Put the third coat on a small patch somewhere out of the way and leave it a day. If it sits down cleanly with nothing wrinkling or softening underneath, you’re right to do the floor. If the patch lifts, wrinkles or goes soft, the second coat needs more time — and you’ve lost a corner instead of the whole job.

Prep

Clean, dry, and free of anything that stops adhesion — oil, old sealer, loose material.

Over epoxy or flake: abrade lightly and vacuum. Solvent wipe before coating.

Over bare concrete: etch with ConEtch, one part to three parts water. Wet the slab first, then apply, agitate with a stiff broom, and leave it 10 minutes. Rinse thoroughly until the run-off runs clear, then let the slab dry completely.

ConEtch is acidic. Gloves and eye protection, and keep the run-off out of garden beds and stormwater drains.

Then check it with the water drop test. Tip a little water onto the slab in several spots. If it soaks in within a minute and darkens the concrete, you’re ready. If it beads, the etch hasn’t got through and that area needs grinding.

Over bluestone: clean back to bare stone and let it dry through. Bluestone holds water longer than it looks like it does.

Safety

Flash point 32°C, VOC max 350 g/L. Keep it away from ignition sources.

Roller or brush only — do not spray. Work with the door open, and use a respirator with organic vapour cartridges rather than a dust mask in any enclosed space. Clean up with xylene.

Sizes

4 L and 15 L. Download the TDS · Download the SDS

Not sure whether your surface is ready, or whether today’s weather suits? Call us on 0411 120 030.