Tuesday, 23 June 2015

How to remove paint from sandstone

This post really should be titled "How on earth do you remove paint from sandstone?" - followed closely by "why would anyone paint sandstone - particularly dark green?!"

The latest project for The Crooked Cottage is trying to do something about the horrible front fence.  You always hear about "curb appeal" when you see any kind of home renovation show, and our place is seriously lacking in appeal.  

First we have a retaining wall.  In the past year I have noticed some deterioration, and I have to admit I have helped it on its way by pulling off bits of paint that have flaked off. During some of the heavy rain some small stones have dislodged and I have realised some of the green colour is actually moss.

Underneath that green paint I was pretty sure it is sandstone, although the left hand side does also seem to have some layers of brick on top.  But then at some stage (and I imagine it was some time ago, as all the neighbours talk about the green wall like it has been a long standing eyesore) it has had cement render type substance sprayed on, and been painted green. Maybe to blend in/hide the moss?!

The dastardly green retaining wall.  Complete with cracked render, flaking paint and random weeds.  

And above the retaining wall we have the paling fence.  Like every other painted surface in this place, it's quite clear that paint just keeps getting put on over the top.  Blue is the most recent (apparently done for sale - which probably explains why I don't recall so many rotten spots or obvious cracking on the palings) over green, over white.  But apart from an occasional paint coating this fence hasn't been cared for, and it is now rotting on many palings.  

Rotting palings with cracked paint
So I decided that I would change the fence palings.  I pulled one off (very easy as they keep falling off due to being rotten) and took it up to Fedwood - I figured I could just buy some new palings, nail them on, paint them white, and hey presto - new fence.

But the posts are also rotten.  And palings are more expensive than I realised (particularly custom made ones to match my rotten ones).  So then I thought - ok I should get the fence replaced.  And that started me thinking about the retaining wall, as it seems stupid to redo the fence, only to late do something about the retaining wall.

As my neighbour is always a) out working on his house and b) probably very keen to get rid of the eyesore too we had a bit of a discussion over what I could use to get rid of the paint.  First up I borrowed a pressure sprayer - we thought it would be fairly easy, but unfortunately we were wrong.

Next step - and by this time another neighbour had joined our conversation - so he brought over some acetone to try out.  We didn't want to use paint stripper, as we didn't want to eat into the sandstone.

Acetone didn't work either.

So then we tried a heat gun - which sort of worked.  In a slow way.  Heat gun, peel paint, and repeat.  Followed by another go at the pressure spray, which worked a bit better on the brittle paint.

Initially I put in about 2-3 hours of effort last week.  

Initially I just worked on the steps.  Hard to believe this is a good two hours work!
Then my husband and I spent the better part of Saturday on the same jobs.  Add a few burns for me (it's easier to peel the paint without gloves on - I know that is not as safe - and I have the burns to prove it!) but a bit more result.  Then we also started on the retaining wall - using a hammer and chisel to remove some of the render areas.  This was more successful - but still slow.

After another days worth of work

Chipping off the render haas assisted - some of this green is now moss not only the paint!
Sunday - I bought sandpaper, 40 grit so it is super coarse.  With no luck!

So I have to just face the fact this is going to be a long, slow process.  Unless I decide to get a sandblaster out - although I am not sure how expensive that would be, and also I don't think that would be very safe for the cars in our very narrow street.

After more work on Sunday - please excuse the weeds!  They will be destroyed by the heat gun when I get to that part

And a little bit more removed after a few more hours.

Any suggestions will be happily taken and tested out!  I'll just be outside my house peeling paint.  At least it is good for meeting the neighbours - I've never had so many stop and tell me what a good job I am doing, and how it is worthwhile, and it will look so good once it is done.  Fingers crossed!


  1. We have just finished renovating the front of our house, a bungalow, sandstone & brick & had some similar issues. Just showed my husband what you are working with, this is what he thought he would do. With an angle grinder with a concrete re-facing blade scuff of most of the faces of the stone, wire brush any remaining paint off. You can use a combing hammer to repattern or reshape the stone & get any grinding marks out. You won't be able to get all the paint out of the joints, when you repoint this will cover it.When you repoint use a mix with more lime than cement, you don't want it to be a hard mix, you want the moisture to come up through the pointing not the stone. Hope this helps.

  2. Thank you that really does help! I did try the angle grinder but not with the right blade I think. I will write this info down and go visit my local hardware store to see if I can get the right kind of blade and tools! Thank you very much

  3. Hi There
    How did you end up going with this? I have a similar problem with gawd awfull blue on sandstone and am looking for advise. Tried a Pressure washer but thinking of using paint stripper as I don't have any other options.

    1. Hi sorry it has taken a while to reply! In the end I just kind of resorted to the hand removal and gradually peeling bits off. I was too worried about the tools and the pressure spray as both of those ended up chopping into the sandstone. I didn't try the paint stripper as I did that inside the house and was worried that stuff is too harsh. My sandstone is quite old and crumbly so as time is going by it is getting easier to peel the paint but I am finding that the stone in generally is crumbling away a bit more. I find it easier to peel sections after a few days of rain, but once it has started to dry out a bit, then it seems to come off easily off the stone.

      Good luck with it!!

  4. Since vehicles no longer has access to it, it will
    be a cozy workshop for the production of Mule Mountain Banjos.fence installation cost

  5. This article is very helpful and informative. Cleaning with water blaster is so much faster and cleaner. Thank you for sharing!

    Airless Spray