Removing soot from sandstone

[Black Cat]

Not really tiles, or whatever, but ...

A lovely elderly lady I know has some sandstone blocks that were used as the back of a chimney for many years. Is there any way of removing the soot and accumulated creosote etc without damaging the stone??:C

[Bedford]

We've had some success cleaning that sort of thing with oven cleaner, takes a few goes but you have to watch the fumes.:)

[woodhunt]

We wanted exposed sandstone on our lintels and after a bit of spot experimenting (orange stripper, scrapers, abrasive papers etc) found that one of those stiff rotary wheel brushes on an angle grinder got it off cleanly (steel, not copper!).

The brush did take a very light, controlled hand to work it off properly, and would totally depend on sandstones condition....

If you wanted to go down the liquid/paste route maybe try one of the eco strippers/peelaway first as they might be a bit kinder to old absorbent sandstone.
I would be worried the creosote might go further into the sandstone so do a spot test first as usually you don't get that much thickness to play with with some sandstone features, although Bedford's said he's had success.

If trying the abrasive route I'd mask up face-wise and area-wise so the lovely elderly lady doesn't breathe in the stuff over the next X weeks/months.

Hope this helps,
G

[Black Cat]

Golly, thanks for those ideas guys - will pass it on to Jean and see what she thinks. Will also offer to do it for her if all else fails ... She is truly one of god's gifts this one.

[thetrooper]

karcher it prehaps ?


scott

[woodhunt]

Scott's suggestion is good, but just be careful/very gentle if you are going to karcher it and obviously check out the sandstone first.

I once had an overzealous mate take out some cement mortar on my front wall and a small corner of one lintel before I could see what was happening- he was just so excited that the paint was coming off he didn't notice what was going on with the mortar...

No, it wasn't me, but I could have easily made the same mistake:B - it was on the karcher's lowest setting!

Cheers,
G

[Black Cat]

Cool. Will go check out what she is talking about and then order in the reserves. I like the sound of a karcher - always did want to give one a go...

[thetrooper]

yeh indeed a great tool in the right hands

b/c this may what u need...tho we have the big mofo for exposed agg panels at work

Rotating washing brush for < 800 l/h high-pressure cleaners (http://www.karcher.com.au/aus/Products/Professional/Accessories.htm?&sdp=ac&pid=47622840&accessoriesGroupName=Rotating+washing+brush&pn=Rotating+washing+brush+for+%3C+800+l%2Fh+high-pressure+cleaners&title=Rotating+washing+brush+for+%3C+800+l%2Fh+hig h-pressure+cleaners&refP=%2Faus%2FProducts%2FProfessional%2FAccessorie s.htm%3F%26accGrNm%3D10002133__Rotating%2520washin g%2520brush)

[Black Cat]

ooooooo that looks like fun - are the bristles hard, soft or somewhere in between? Sort of a giant version of those things you run off the hose (if you are not on tank water).

[thetrooper]

some where in between cat man ... when you are next in the big smoke go se if you can have a look @ bridge water h/s and the exposed agg panels they look a treat !



cheers
scott

[Black Cat]

Bother. Was in bridgewater today, but forgot to read this thread before I left. Will check it out next time I am down in the big smoke. Thanks Scott.

[Black Cat]

Well I passed on the suggestion, but then it turned out that the fire is in a room with carpet on the floor (here was me thinking it was in a bit of a ruinous situation). So flooding the place with water is not an option. Bother once again. Will go over the other solutions and see what we can come up with. (I did suggest claiming the carpet on insurance but she declined, lol.

[johnc]

Applied Chemicals Pty Ltd had a granular stone cleaner which you mixed with water that was very effective on fireplace black. Mildly acidic it needed to be washed off later with clean water so perhaps not ideal unless you have a bit of plastic handy. You applied it with a stiff scrubbing brush or wire brush for heavy build up.

I can't remember the name of the product but it was perfect on material like granite and basalt but not much good on marble. It also did a fantastic job on cleaning the gunge from neglected toilet bowls, probably cleaned the S bend and the next 100 metres of sewerage pipe as well.

I'd start with oven cleaner myself and go from there.

[Black Cat]

Great, thanks for that John