Painting a concrete floor that's been power floated (etching?)

No takers?

Who made the suggestion about etching?

What sort of paint?

Have you tried contacting the paint suppliers?

Here's a sequence of URLs

This has a link:

Click on the TECHNICAL tab, and you'll see the acid has a specific gravity of 1.1

Click on the DATA SHEETS, and then on the Safety Data Sheet, or click on this

Scroll down to Section 3 Composition/Information on Ingredients, where it tells you it's hydrochloric acid.

The sum of all that is the etching solution is hydrochloric acid, aka Brick Acid, of specific gravity 1.1

A hydrochloric acid solution with a specific gravity of 1.1 is about a

This particular Brick acid on ebay has a strength of 18%.

The instructions for the Promain acid say

"When applying Acid Etch to a floor you will notice the solution will fizz this is the acid reacting with the concrete, the Acid Etch needs to be applied until this fizzing stops. After application of Acid Etch to a floor the floor will need to be rinsed with clean water to wash the acid etch away and allowed to completely dry before the floor paint is applied. This is especially essential when applying solvent based floor paints or line marking but when applying water based floor paint it is not as critical. When calculating the amount of product required we would suggest you base your calculations on approximately

The 5l container of acid on ebay will treat 100 sq.m.

Just be careful when you're using it. It's quite strong acid. Read all the precautions for the Promain acid, and follow them. Wear rubber boots, rubber gloves (Marigolds?) and goggles or better, a full face visor. If you get any on your skin, rinse it off immediately. Don't be cavalier with it. Keep the kids/pets indoors.

Keep it far away from zinc, steel, iron, tools, ...

The hydrochloric acid fumes will cause rust and corrosion, and will spread.

Thomas Prufer

The main thing to be aware of is to be sure there is a damp proof membrane beneath the concrete. If not,forget it, the paint will flake off due to trapped rising damp.

Diluting it add the acid to bulk water not the other way round. (it isn't much of an issue with HCl but is lethal with H2SO4)

Also I'd wear good strength neoprene rubber gloves - Marigolds are OK for doing the washing up in a kitchen but they puncture far too easily.

Move anything metal out that might be affected by the fumes/mist that will inevitably rise from the action of the acid. You probably want to apply it and leave it to react rather than breathing an acidic mist.

In which case you use a 2-part epoxy paint that is designed to act as a DPM before applying a wooden floor.

Thanks! That's all extremely useful - A-level chemistry was a long time ago.

Fortunately the only metal is an oil pipe and roller doors, and ventilation is fairly easy.

A-level chemistry was 45 years ago but the one relevant thing I can remember is AAA (Always Add Acid)

It's an empty room and ventilation will be good

Are you sure you have concrete, that might need etching, or a screed, which doesn't?

Yes, I spec'd it.