Removing paint from outside concrete

pepp77

pepp77

pepp77

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The outside window sills in my house are concrete plinths and have been painted in the past. The paint is peeling very badly and I want to strip it back and repaint.

Using sandpaper seems like a waste of time, and I have tried using a wire brush to scrape the more flakey bits off but they dont really seem to want to come.

I was therefore thinking of getting something like

https://www.amazon.co.uk/Silverline...d=1463569599&sr=8-3&keywords=drill+wire+brush

and using it on a cordless drill (as I need to do the upstairs window sills)

Do you think this would do the job.

You can just make out the sill in this picture

986d33a5-7a21-4ba2-b63c-22b4176031df_zpswmzti7ui.jpg
 
I think I would try a rotary brush, which are easier to control in a power drill in restricted environments I found, and you can easily see your progress , not sure if steel would be too aggressive versus brass wires since I have never removed paint from concrete .... plus the safety goggles of course .. maybe someone will say if there are good chemical solutions.
 
I had the misfortune of doing this on the sills on our last house. They were in excess of 100 years old and were covered in layer upon layer of paint to the point that the texture of the sill was lost entirely. The easiest way to strip them is also the most messy i.e chemical stripping. You can make an inexpensive poultice using caustic soda, flour and water. The flour just helps form a paste. Apply liberally to the sill and cover with cling film to stop it drying out. Make sure you cover yourself top to bottom unless you want a free and painful tattoo! Nitromors or similar will work, but you will spend a small fortune buying off the shelf. Make sure you clean the whole sill thoroughly before painting.
You can buy off the shelf kits that work on similar lines as the home made stripper, though achieve much the same result.

I did use a variety of wire wheels in the first instance, but found whilst they will remove the flakes, they will just polish the non flaking bits.

Alternatively just do what most would do and remove the worst of the loose stuff and just paint over :)
 
I assume a pressure washer would not work, with the power heads I have inadvertently removed paint on outside render of a house (but I suspect it would use too much water and be difficult to control without breaking a window say.)
 
Cheers

Think I will grab one of the wire brush things as they are only £3 and I can have one for the weekend.

Not sure on chemicals, I used some of that peelaway stuff previously in the house on old gloss and it was pretty good, but it is expensive.

I a trying to remember to a year ago when I did the ground floor sills and I think I just used a normal scrubbing brush to get off the worst and then painted over the non flaking bits (so will probably end up doing that again, especially as it is the upstairs this time and so not exactly close to the eye :)).

Pressure washer is out as 1 I think it will be too much for the area and 2 I am not lugging a pressure washer up a ladder :)
 
Orifice said:
You could hire a needle scabbler, might be overkill for the small amount you have to do.
Click to expand...

Yeah probably. I do have a 4" grinder I could try as well, but that currently only has a standard 6mm grinding disc on it.
 
In and industrial environment this would be a classic job for a high presure jetter, high energy low flow rate great for removal coatings without damaging the substrate.

I once got some guys in to do jetting at 25,000psi (yes thousand or 2,500bar) they had to wear kevlar body armour and have a 2 man dead man switch set up for safety. Removed the coating left the brass untouched.
 
400ml of nitromors >£8 and as suggested will need to make a poultice and keep it wet whilst it does its stuff , potentially on underside of ledge too
 
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