Preparation before polyurethane concrete floor paint???

[ondablade]

Wondering if anybody has experience of how best to go about painting a roughly 2.5 x 2.5m power floated concrete floor - actually a sharpening/office/storage area beside my workshop.

The floor isn't all that polished, and the same type of floor in the main workshop area took a two pack epoxy primer and finish without any bonding problems about eight years ago. In that case (the building was empty), and i went over it with a concrete grinder first.

I'd been hoping this job could be done by just vacuuming and painting it with a grey polyurethane floor paint - the local supplier (they make their own line of paints) advised i could just paint the stuff they sold me straight on. It's made by an outfit named Blackfriar in the UK, and carries the brand 'Crusader'.

Not so far as i can tell from the web, and not according to Blackfriar's tech guy. Options include grinding the floor and priming with an epoxy primer, and finishing with a polyurethane or an epoxy top coat - none of which appeals due to the dust (machines next door), the labour and the cost. The other option seems to be to etch it with hydrochloric acid, but by all accounts that's not a pleasant option either.

It's not coming up as an option, but i wonder would a wash with something like a PVA concrete bonding agent work? Anybody got any ideas for an alternative finish?

 

[RogerS]

Farrow and Ball Floor Paint

http://www.farrow-ball.com/pws/client/i ... _Paint.pdf

 

[misterfish]

Sounds just like the stuff we used in our previous house. In our case on the concrete surface in the utility room. We did this after we moved in - just cleaned the surface (vacuum, then wash with mop and bucket and floor cleaner) and let it dry. It surprised me how well it seemed to stand up to water and shoes, though it wasn't a thoroughfare.

If I was doing it now I would probably be more thorough with preparation, but that's just me being OTT. SWMBO who actually did the floor is still impressed with how good it was - she just described it as 'beautiful stuff'. The version she used was recommended for garage floors.

Misterfish

 

[PhilM]

I used & can recommend Leyland floor paint on my concrete basement floor; the painters on a job I am working on used Farrow & Ball as recommended by Roger.

Any specific floor paint should do the job, the Blackfriars paint could be as good as any, just follow the instructions.

Phil

 

[ondablade]

Ta guys. It seems based on more digging since my original post that a clear acrylic based concrete sealers that soak in like Ronseal's One Coat are a good primer that can deal with a layer of fine dust.

The problem is that this fine concrete dust/efflorescence (exuded calcium salts) form a layer that many paints can't penetrate - which is why a some form of surface preparation is fairly clearly advisable.

The Rolls Royce job is to grind or acid etch the surface before priming, but i think i'll go with the Ronseal and the Blackfriar's polyurethane and hope for the best.

 

[Thomson0]

Acid etching the floor isn't all that difficult you could use a decent acid based brick cleaner which will etch the floor enough to make the paint stick. The problem with power floated floors is that they are almost mirror like and the paint cannot get a mechanical key. Btw as a time served painter and decorator with 31 years experience I would not use Farrow and Ball paints to paint the inside of my pigeon loft!

Hope this helps

Thomson0