Repointing - Oh God I am confused

[Nemesis]

We put water into the lime - scientific method is - bung it in until it looks right!

Cream cheese. Think - sand castles - if you turn a bucket out, it stays in shape.

If too wet, leave to stand and the water will come to the top and you can pour it off (but try not to get into that situation if you can help it).

Or buy a tub of ready made putty! More expensive though.

 

[MdB]

Right, so if mixing up a large quantity of lime (say in the recommended old bin) is it better to stick water into the lime or lime into water? If it is the latter what proportion of water to lime approximately?

See here and the posts above / below.
(I may have gone OTT on the dangers but please wear a mask)

 

[Penners]

If too wet, leave to stand and the water will come to the top and you can pour it off.

Is that water useable as limewash, or is it too "thin"? Or have I misunderstood what limewash is?

 

[thiambal]

Ffs!!

Stripped skin, knackered lungs, blindness,

Hang on, is my school boy chemisty escaping me or isn't lime and chalk essentially the same thing. Why then are there no hordes of blind breathless history teachers around!

 

[biffvernon]

The order doesn't matter with hydrated lime (It does matter with quick lime, but you're not doing that). And the ammount of water doesn't matter - just add more than you need so there is an inch or two of water standing over the lime when it's all mixed up and has settled overnight. You tip that off when you come to use it.

 

[MdB]

... lime and chalk essentially the same thing....

Limestone, chalk, shells and lime mortar are basically the same thing being carbonated lime (calcium carbonate - CaC03). This is generally safe (don't drop limestone on your foot!). Hydrated lime is calcium hydroxide (Ca(OH)2) which is the more dangerous stuff. It reverts to CaCO3 over time with exposure to air. (Quick lime is the really dangerous stuff but you won't find that at B&Q)

I guess hydrated lime is a bit worse than cement but not by much. You don't want to have either on your skin for any length of time nor do you want to breath either as a dust. Most builders take few precautions but they should.

 

[Jon Maine]

Is that water useable as limewash, or is it too "thin"? Or have I misunderstood what limewash is?

To thin, however should you have a stone which has turned to weetabix you wish to preserve spray it to saturation say 50+ times over the course of a week or two and the stone should reconsolidate and increase its durability. Probably best taken off the top of freshly reacted putty for best results.

 

[Penners]

Jon - that's very interesting. I presume it has to be limestone for this to work?

 

[Jon Maine]

Certainly limestone, possibly would work on other stone too, I see no reason why not. I do out of choice tend to replace stone when it is that bad as I consider ongoing maintenance issues as a big negative. However there are definately times it would be useful for irreplacable items. My general rule of thumb is if its lost its shape but still solid keep it, maybe pack it out a bit with lime mortar with stainless wire and screws to remove water traps, not to make it look like a new stone. Chop it out if its weetabix!!

 

[Penners]

Chop it out if its weetabix!!

Sounds sensible, but I couldn't eat three.

 

[MdB]

Certainly limestone, possibly would work on other stone too, I see no reason why not.

Others have said that limewash and sandstone don't go together well.

 

[Gareth Hughes]

Is that water useable as limewash, or is it too "thin"? Or have I misunderstood what limewash is?

To thin, however should you have a stone which has turned to weetabix you wish to preserve spray it to saturation say 50+ times over the course of a week or two and the stone should reconsolidate and increase its durability. Probably best taken off the top of freshly reacted putty for best results.

Ah, limewatering. Why I am not surprised to see that you're posting from the Westcountry, where the application of limewater is a curious observance practised by many adherents of the conservation cult?

I've always been under the impression that it comes somewhere slightly above electro-osmotic damp-proofing and slightly below sacrificing a goat in the heirarchy of effectiveness of things that make no sense that people do to protect their building. But quite a few people I know and respect swear by it so who am I to question their faith?

Presumably it's a miniature version of the Mother Shipton's Cave and Dropping Well effect?
http://www.mothershiptonscave.com/the_petrifying_well.htm

 

[Jon Maine]

Thats funny you should say that, I forgot to mention the bit about adding the goats blood too.

 

[MdB]

I've always been under the impression that it comes somewhere slightly above electro-osmotic damp-proofing and slightly below sacrificing a goat in the heirarchy of effectiveness of things that make no sense that people do to protect their building.

Any reason why you think it doesn't work? My water bucket with a very weak solution of lime in it easily produces a layer of limestone on its surface as the water evaporates. Why wouldn't the same thing work in porous rock binding it together? Just curious, I don't know if it would work one way or the other but its not obvious to me why it wouldn't work. (I am attempted to give it a test though )

 

[Gareth Hughes]

I've always been under the impression that it comes somewhere slightly above electro-osmotic damp-proofing and slightly below sacrificing a goat in the heirarchy of effectiveness of things that make no sense that people do to protect their building.

Any reason why you think it doesn't work? My water bucket with a very weak solution of lime in it easily produces a layer of limestone on its surface as the water evaporates. Why wouldn't the same thing work in porous rock binding it together? Just curious, I don't know if it would work one way or the other but its not obvious to me why it wouldn't work. (I am attempted to give it a test though )

Here's Bruce Induni on the Lime Method:
http://www.induni.net/page24.html

Prof. Robert Baker developed a set of techniques at Wells Cathedral to provide an alternative to silane consolidation. This has come to be known as the 'Lime Method'. Its adherents tend to be outspoken advocates....Baker himself was obsessively secretive and somewhat pugnacious. This combination has polarised consolidation into a 'pro-silane camp' and a 'pro-lime camp'.

The 'Lime Method' of consolidation consists of four processes : lime poultice cleaning, lime mortar repairs, lime watering and sheltercoating. Only the lime mortar repair element is (relatively) uncontroversial.

My experience at Wells Cathedral suggests : lime poultice cleaning is ineffective and dangerous : lime mortar repairs can be effective and durable : lime watering works, but for the wrong reasons : sheltercoating is like the 'Emperor's new clothes' (i.e. It isn't really there at all)....Consolidation with limewater and protection by sheltercoating has attracted a strong following....the evidence is equivocal. That limewatering does something is beyond contest. What it does is a more difficult question.

 

[MdB]

Here's Bruce Induni on the Lime Method:
http://www.induni.net/page24.html

That is a very interesting link. Well worth reading. Thanks.

 

[Nemesis]

The architectural practice Jon used was connected with the work on Wells I believe.

http://www.cotac.org.uk/articles/people/caroe.htm


http://www.stone-mason.co.uk/limetechnique.php

http://www.english-heritage.org.uk/upload/pdf/cb_45_p33-35.pdf

 

[Nemesis]

http://www.buildingconservation.com/articles/lime/hylime.html

 

[Jon Maine]

Yes Caroes were my architects on Merchants House, their office is next door to Wells Cathedral.

I believe limewatering does some good, although there comes a point you need to replace the stone.

As for shelter coat as much as anything I think it is good as a sacraficial layer which helps the old and new stone weather in to match at the same rate. There is an opinion that it helps the surface of the stone calcify more as the coating gradually wears off rather than letting a "green" stone at the elements rapidly.

 

[Nemesis]

Hmmmm....


http://periodproperty.co.uk/forum/viewtopic.php?f=1&t=9337&p=106427#p106427