Preventing limewash dusting, internally

[FamilyWiggs]

Well, I'm now limewashing the snug on top of the new lime plaster I've been doing.

I added a little bit of linseed oil when I limewashed the workshop walls internally. It didn't seem to make much difference to dusting though. Not that it really mattered there.

The snug though will have soft furnishings and real people allowed in it. :shock:

Anyone able to advise on the causes of dusting, especially relating to technique of application?

Anyone able to suggest appropriate additives for internal walls? Tallow or fresh virgins blood are perhaps not desirable here. The final couple of coats will be coloured with natural ochre pigment.

My mix is 1:1 putty to water, with nothing else. Second and subsequent coats will be thinner, but this coat is a bit thicker so as I can fill shrinkage cracks, etc. I sprayed the wall first but they are very dry and it is very hot. I am getting a little dusting. Not much, but ideally I won't have any.

Any help gratefully received.

 

[DJH]

I find that wetting the wall first and then applying thin coats daily over at least four days dampening each time will do the trick.

Doug

 

[FamilyWiggs]

Thanks Doug - will try that after the initial thicker coat to fill cracks.

 

[DJH]

I think thick coats will end up with a dusty surface. Thin coats will fill even the largest cracks after a while as I've found...

Doug

 

[FamilyWiggs]

OK -will think it out further first. Maybe a 1:2 mix?

 

[DJH]

Not sure about the mix ratio. I use White Rhino lime in a very watery mix and go by the consistency...

Doug

 

[FamilyWiggs]

It seems to be working - not getting any of the first coat off now. Doing lots of damping down as it is a newly plastered wall and suction is very high.

It is about the same consistency as milk, maybe a trifle thicker.

I can see brush strokes - but I guess that is simply because the wall is not yet saturated with colour.

I'm intending to put on 2-3 coats of white, and then a couple of coats of natural ochre mixed in with the limewash.

Sound about right?

 

[JoceAndChris]

You know much more about it than me but, for what it's worth, I think brush strokes remaining visible is both desirable and unavoidable. 4 coat work is generous. Casein is added to limewash to prevent dusting, I've got casein in the little loo and no dusting.

How are you going to remember your formula for colour if you need to touch up in future? Is it just a question of mixing in until it looks right?

 

[FamilyWiggs]

You know much more about it than me but, for what it's worth, I think brush strokes remaining visible is both desirable and unavoidable. 4 coat work is generous. Casein is added to limewash to prevent dusting, I've got casein in the little loo and no dusting.

How are you going to remember your formula for colour if you need to touch up in future? Is it just a question of mixing in until it looks right?

I will try and be precise about the measurements. I suppose it might be possible to keep a tin it mixed somewhere for touching up. WHen the whole lot needs doing, it's less of an issue as the colour will be consistent again.

 

[Zebra]

Was going to say I don't think a thick coat on first is a good idea, as it may crack out from underneath after you've got all your nice top layers on. This happened on one of my walls, and I had to peel, brush and scrape the lot off and start again. That was externally though, so it could be that sun had something to do with it. Thinking about it, I've done quite thick coats in some fiddly corner areas indoors and it's been fine.
I think that only thick coats go dusty. Thinner coats seem to carbonate better and all the lime sticks to the wall.
Reckon though it's a good idea to keep a jar of the final mix you make for the top coat, for touching up in future. Very difficult to get the exact mix again. I've got a couple of jars here, labelled up with what room they came from!

 

[Gareth Hughes]

Surely clearing up any detritus is Mrs Wiggs' responsibility anyway? :twisted:

 

[FamilyWiggs]

Surely clearing up any detritus is Mrs Wiggs' responsibility anyway? :twisted:

I'll be sure to let her know you said that Gareth. By email I think, though, just to be on the safe side

She seems worried that the limewash may come off on her "soft furnishings", whatever they may be.

Doug's advice and technique are working - no dusting at all this morning now the first coat has dried.

 

[Ebenezer]

I found it hard to apply thin enough coats. It always seemed like I was barely putting anything on, then it still dried dusty! Also I found the white limewash that I used from mike wye to be almost like water when first applying but when it dried it appeared to cloud and thicken. Misting a bit of water on every couple of hours after seemed to help to prevent dusting. I never quite got it right though.

 

[JoceAndChris]

I realise now that one of my big mistakes was not using an electric mixer. It's no good leaving that pigment sitting on the bottom of the tin.

 

[MatthewC]

I realise now that one of my big mistakes was not using an electric mixer. It's no good leaving that pigment sitting on the bottom of the tin.

Using one of those long blue mixer things on a drill, I presume? And you also have to remember to stir it often whilst applying, like every 10 or 20 minutes, as it settles very quickly.

I agree with Zebra re thin coats - I did this and it has never created dust as far as I can see. NB I purchased the mixed limewash in order to not introduce a variable which I didn't understand into the process; I have no idea what mix Mike Wye use.