Cleaning concrete before paint

[Bobupndown]

One of these years I'll get round to painting my workshop floor. It's bare concrete currently but has had many an oil spill over time. What would I be best to use to stop oil residue from preventing floor paint sticking properly?

 

[angellonewolf]

not that ive tryed it but get as much oil out as you can sand cat litter seam to be good


then try an oil remover do this till you cant get more


the sbr the whole area and then use paint ?

 

[Endeleus]

I did mine years ago with some solvent-based ronseal sealer before I painted and never had any issues over the old oil stains

 

[Pete.]

9" grinder with a diamond cup wheel and home made hoover adapter to catch the dust. It'll not only remove the surface stains but take the fat off the slab so the paint won't come up so easily when you're working on it.

 

[richie00boy]

If you have a wet vac then hot water and biological washing powder works well, will need a few treatments. Vac up after 20 mins soaking, final couple of applications just plain hot water to extract the detergent remains.

 

[500e]

Don't use SBR and paint over

 

[Chriso996]

Painted mine with a resin paint, from memory before painting I used a brick acid to prep

 

[MattF]

Don't use SBR and paint over

Why?

 

[brightspark]

if the concrete is scuffed up and cleaned and is porous you can coat with sbr before painting and will seal it

 

[500e]

Have found better to just paint on all the floors we do

 

[premmington]

Don't use SBR and paint over

SBR or PVA - water gets under and it peels off with paint adhered to top of it.

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Cleaning concrete floors pre paint - sugar soap or more expensive TSP (trisodium phosphate). Bucket and mix with kettle fulls of scoulding hot water - stiff yard brush - hose off with clean water to rinse. Works a treat.



It's filling concrete floors prepainting I struggle with - chips and cracks - I tried everything - and I can't get anything that is easy to level to stay in...

 

[500e]

Correct @premmington
Ask how we know, then you have to remove it.
We tried it Once then ground whole floor, may be ok if insulated floor but we just clean and paint

 

[brightspark]

sbr is waterproof and used in damp proofing for bonding . pva isnt waterproof and re emulsifies sbr is used for tanking walls and floors as a slurry mixed with cement

 

[premmington]

Correct @premmington
Ask how we know, then you have to remove it.
We tried it Once then ground whole floor, may be ok if insulated floor but we just clean and paint

@500e - oh yeah I too learnt the hard way . PVA cannot stand water - SBR cannot stand "mixed garage fluids".

Sugar soap/hot water/yard broom/rinse off let it fully dry. Thin first coat down to soak in - allow to fully dry - then top coat.

"Resincoat" been my recent choice of two pack paints and filler/crack repair.

All Products | Resincoat

Shop all products from Resincoat a leading manufacturer in epoxy resin coatings. All resin products manufactured in the UK ensuring high quality.

www.resincoat.co.uk

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But... None of it lasts long on a busy workshop floor - none of it.

I not sure if the no name cheap 20ltr tubs of thin smelly light grey paint (that dries quick) - is as good as anything to be honest?

I have had expensive - two pack stuff lift off after a month - when a big hot radial tyre from a sports car has parked on it.

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I have had a lifetime of painting garage/workshop floors. My workshop floor needs doing again - I really can't be bothered - it is downtime - hassle moving stuff - painting yourself out of the door - looks OK when it is done - but it don't last. A busy workshop floor is like the "Forth Bridge" - the painting is never over - never...!

Big high volume 30" fan - is your best friend if you don't want sticky floor the Tuesday back after a bank holiday floor painting.

If you got a nice powerfloated floor - with a hard surface - just fill the chips with epoxy - wash it down. NEVER PAINT IT...

 

[Onoff]

9" grinder with a diamond cup wheel and home made hoover adapter to catch the dust. It'll not only remove the surface stains but take the fat off the slab so the paint won't come up so easily when you're working on it.

Basically what I did with my double garage a long, long time ago when it was near empty. Albeit I used a 4 1/2" grinder. Never used as a "working" garage the concrete had no oil stains etc to worry about.

I then vacuumed it all up after taking the laitance off.

I'd acquired lots of different tins of single pack grey floor paint from various sites, some full, some half used. I sacrificed a 5 gallon brewing bucket and mixed them all together. Made a shade of grey I'll never recreate! Applied with a cheap plastic broom. It still looks good...if only I could see it.

 

[Gritineye]

Big waste of time and money, prepped and painted my garage floor once, looked great, it soon wore off not a speck of it left now even in the corners.

 

[Onoff]

I also acquired some yellow floor paint about the same time I got the grey. I had grand plans to mask the grey and paint designated walkways like a proper garage. As time has passed and my hoarding tendencies have ended up making the garage an unusable, unorganised mess, it seems daft just to highlight the remaining 1m² of floor space that's left.

...I think it might be <1m² now...

 

[RichardM]

Painted mine with bought paint and some I got from work when they were checking it out. Bike tyres soon lifted it. Just put some vinyl flooring I have down instead. Dusty concrete with peeling paint is now hidden.

 

[premmington]

Painted mine with bought paint and some I got from work when they were checking it out. Bike tyres soon lifted it. Just put some vinyl flooring I have down instead. Dusty concrete with peeling paint is now hidden.

Unreal how a hot radial tyre will lift floor paint is it not....?

 

[frank horton]

I helped a printer friend with his old floor......
he bought a 4 colour printer, heavy, huge beast....and needed a dust free floor for the future....
the floor was part of a railway yard building bricked off into units.....
the floor was a right mess...bad cracks flaky holes and god knows what was spilt on it....
Used degreaser and a power washer on the known oily bits...under his old printer machines.....
once almost dry filled the holes a bit/layer at a time with latex leveling compound....several layers deep in places...
then a gang of us did the whole floor.....after a week drying we brought the machines back in on roller scoffold poles....
The floor was still good after many years, then I left the UK again so no idea.....but he never complaind....
he was happy with the grey col so never painted it.....He reg used a mop and bucket to clean the floor.....