Is this plaster of paris and lime ?

[Pads]

Can any one identifiy these products ?

Blanc Mineraux de Paris

Chaux vive Broyee

 

Am I right in thinking they are Plaster of Pais and Lime ?

What do you use Plaster of Paris for except broken arms and making models ?

Many Thanks [:)] 

[pachapapa]

Blanc Mineraux de Paris, name of a company that presumably produced mortier blanc mineral.

Basically a very fine white cement sold in bags as a mortar, sort of stuff moulded into light roses in the ceiling.

Sold in bags ready for mixing, think repair some hideous floral design.

Chaux vive Broyée, a ground quicklime difficult to find unless you go to a producing lime kiln, commonly used for Ph correction in acidic soils, the slaking of the quicklime is difficult as for proper slaking it is necessary to carefully control the amount of water.

Sometimes and I have seen actually people buy and slake their own lime; the results are usually amusing.

[Pads]

Thankyou Pachapapa

So could I use the Chaux vive Broyee mixed with cement to repoint the stone walls in my barn ?( inside or outside? ) I have inherited a small mountain of it in a barn I have just brought .... or shall I just chuck it on the garden ?

Rare you say does that mean expensive ?[Www] Any one looking to buy some rare lime ??[;-)]

[Théière]

[quote user="Pads"]

 Any one looking to buy some rare lime ??[;-)]

[/quote]

Only if your making a rare G&T [:D][:P]

The quicklime is used to make lime plaster for internal work on lathe ceilings.

Natural hydraulic lime is what you would normally use to repoint your walls.

[pachapapa]

[quote user="Pads"]

Thankyou Pachapapa

So could I use the Chaux vive Broyee mixed with cement to repoint the stone walls in my barn ?( inside or outside? ) I have inherited a small mountain of it in a barn I have just brought .... or shall I just chuck it on the garden ?

Rare you say does that mean expensive ?[Www] Any one looking to buy some rare lime ??[;-)]

[/quote]

I would not be too casual and gung ho about quicklime as when moisture or water is present it changes from CaO to Ca(OH)2 in a violent exothermic reaction; if a child was to swallow it the result might well be fatal; rubbing of the eyes would probably result in blindness or severe injury.

It should be kept in a cool dry place and on no account allowed near water.

It can be used after slaking with water when lime is formed, then used for all those things that lime is used for.

When you say a small mountain, what sort of volume are you talking about.

If it has been lying around for a while it may have become partially slaked by taking up water vapour from the atmosphere.

Quicklime for agricultural use is not finely ground and is "lumpy"; in effect to reduce the wind blowing it away and to rerduce the natural rate of slaking when harrowed into the ground.

You can ascertain the degree of slaking by taking half a shovel full, placing it on dry ground, make a conical cavity in the centre of the pile and then slowly add water; the water will boil and steam will be given off with lots of heat.

Quicklime is commonly added to the graves of dead animals as it causes the quick decomposition of the flesh, reducing the remains quickly to a skeletal remnant.

[Théière]

[quote user="pachapapa"][quote user="Pads"]

Thankyou Pachapapa

So could I use the Chaux vive Broyee mixed with cement to repoint the stone walls in my barn ?( inside or outside? ) I have inherited a small mountain of it in a barn I have just brought .... or shall I just chuck it on the garden ?

Rare you say does that mean expensive ?[Www] Any one looking to buy some rare lime ??[;-)]

[/quote]

I would not be too casual and gung ho about quicklime as when moisture or water is present it changes from CaO to Ca(OH)2 in a violent exothermic reaction; if a child was to swallow it the result might well be fatal; rubbing of the eyes would probably result in blindness or severe injury.

It should be kept in a cool dry place and on no account allowed near water.

It can be used after slaking with water when lime is formed, then used for all those things that lime is used for.

When you say a small mountain, what sort of volume are you talking about.

If it has been lying around for a while it may have become partially slaked by taking up water vapour from the atmosphere.

Quicklime for agricultural use is not finely ground and is "lumpy"; in effect to reduce the wind blowing it away and to rerduce the natural rate of slaking when harrowed into the ground.

You can ascertain the degree of slaking by taking half a shovel full, placing it on dry ground, make a conical cavity in the centre of the pile and then slowly add water; the water will boil and steam will be given off with lots of heat.

Quicklime is commonly added to the graves of dead animals as it causes the quick decomposition of the flesh, reducing the remains quickly to a skeletal remnant.

[/quote]

Quite right, its very caustic, be careful wear gloves at all times.

[ventodue]

[quote user="Pads"]  <snip>

What do you use Plaster of Paris for except broken arms and making models ? [/quote]

'cos it sets quick, can be used for fixing electrical back boxes in solid walls

Amicalement

Craig

[Pads]

Thankyou again Pachapapa..

There is about 30 large sacks ... some have split open but are still dry soft white powder,, and stored in a dry place .. But I will be very careful when moving it and using it.

Is it suitable for mixing with the cement for repointing ? As I have been told to use a lime mix  

[Théière]

Pads, if it is quicklime it will need to be slaked and stored in plastic tubs for around 3 months before you can use it. Then mixing it with sand to form a mortar which has a partial set but cures slowly by absorbing carbon dioxide.

Natural hydraulic lime, the stuff you normally buy in sacs at brico's NHL3.5 can be mixed with sand and used right away as it sets using water hence "hydraulic"

There is no real need to add cement at all.

Hope this helps.

[pachapapa]

Not sure what to write without raising the "ire" of  lime putty evangelists.

However in contrast if you wish I will post for the OP a method of preparing slaked lime without indulging in a three month gestation period.

Personally I prefer to use a mixture of lime and ungraded sand for LIME POINTING and never incorporate any cement.

However wandering around I see that I may be in a small minority.

 

[Théière]

[:D][:D][:D]

I'm in your minority pachapapa, so we should be officially recognised [;-)]

[BIG MAC]

Personally I prefer to use a mixture of lime and ungraded sand for LIME POINTING and never incorporate any cement

 

Isn't that what they did originally? coarse sand and lime?

[pachapapa]

[quote user="BIG MAC"]

Personally I prefer to use a mixture of lime and ungraded sand for LIME POINTING and never incorporate any cement

 

Isn't that what they did originally? coarse sand and lime?

[/quote]

A coarse sand, also called a sharp sand is a washed and graded sand often used for making concrete.

When I specify ungraded sand I mean sand dug from the local sand pit or river without either washing or grading.

Trommels ,screens, vibrating screens etc were rare in local villages in rural france.

[BIG MAC]

Sand coming from a river is likely to have been pretty well washed.

Coarse sand to me is an ungraded sand containing varing sizes and grades of granular silcates and fines.

My point being that it may be tempting to be overly scientific or prescriptive in repair scope definitions when many rustic buildings were put together using pretty low tech methods.

 

[pachapapa]

[quote user="BIG MAC"]

Sand coming from a river is likely to have been pretty well washed.

Coarse sand to me is an ungraded sand containing varing sizes and grades of granular silcates and fines.

My point being that it may be tempting to be overly scientific or prescriptive in repair scope definitions when many rustic buildings were put together using pretty low tech methods.

 

[/quote]

I studied Mineral Technology at the Royal School of Mines, one of the constituent colleges of Imperial College,London.

So I can mix the technical jargon with the best of them; however in posting on this thread I have purposely kept technicalities aside.

However as you insist....;

Coarse sand is a graded sand with retention of the larger particles.

Coarse sand is likely to contain grains of Silica SiO2.

Any fine silcates (sic) silicates would be likely to be derived from clay minerals and undesirable.

Traditional rural houses in france are usually built with the basic materials close at hand and with minimal use of technology.

Despite the evangelical devotion of expatriate UK do it yourselfers who have in the last 15 years worked tirelessly to inculcate into french rural minds the technological concepts of Fine Sand and Coarse Sand.[:-))]

 

[BIG MAC]

Far be it for me to discuss the various compositions of sand with a Gentleman from the Royal School of Mines. Although as I recall when I was looking after RSOM and Kensington Silwood Kent and Hospital Campus for Imperial not once did the Estates Department question me on my knowledge in this regard...Neither did the Academics.

I must have got away with it....Pheww!!

Sand, for those that are interested (Can there possibly be any?)

Particulate matter of varying origin but predominately made up by the erosion and weathering of rock (We all knew that bit) and consequently make up will largely be dependent upon the type and condition of local rocks.

Inland continental deposits  and non tropical beaches are likely to be predominately silica (Silicon dioxide SI02 for anyone still mad enough to be still reading) This due to there often being a high quartz content.

Arkose is a sand or sandstone which contains Feldspar (An aluminium silicate) usually occurs due to the erosion of nearby granite.

White sands found tropically is often a product of the breaking up of coral often assissted by its passing through the digestive system of the parrot fish!

I could go on to volcanic sands or gypsum sands....but I wont.

My point is (Jeez- Louise!) In times gone by people dug up their sable chucked some lime and the wet stuff in with it and poked it in the gaps in their walls. I don't think they got too hung up on what it was called or indeed how fine it was and I was avocating the earthy principle of doing likewise based upon the scientific principle that if it's lasted for 200 years on my house why bother being any more scientific.......

[Théière]

Everything removed from the ground at our local rural sableier is graded, as it has to be certified, in our case either 04 or 02 all forms filled out in triplicate. How do you obtain ungraded?

For the purpose of lime masonry you need a good mix of course to fine grains.

Would still like to hear about making lime putty without the three month wait

 

[BIG MAC]

 Teapot If working here I would buy it ready batched it's too much of a H&S / Commercial Risk to do otherwise. In France I should imagine back in the day they probably had mini batching plants bit like the concrete works of today knocking up the mortar of the day. I have heard tell of using cement in mixes and a sand cement chalk mix but TBH when I get round to it I would rather figure out what the good old boys did and replicate it if it's not too silly.