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Bagged premixed lime mortar for tuckpointing

85K views 158 replies 18 participants last post by  dom-mas 
#1 ·
I have a tuckpointing job I'm bidding on that we need to use lime mortar for. The building was built in 1900.
Does anyone make a good premix for this purpose?
Any help would be appreciated.
Thanks.:thumbsup:
 
#103 ·
I do not mean the face, I am talking about the whole brick. I have buff bricks and dark red bricks made from the same clay body. They add minerals and adjust the amounts of clay from different pits, but before production the clay body is indistinguishable to the eye. Robinson brick (now owned by General Shale) has been producing the same color range of brick for 30+ years using various and assorted quarries. They excel in maintaining the color match year to year by close control of the properties of the blended clay body.
 
#104 ·
Well when I was a kid my mom signed me up for pottery class. There were 2 types of clay there. a grey/white clay and a brown/red clay. When we would fire them the grey/white would become buff and the red/brown would become red. The same colour as the 2 bricks I'm describing.

Later when I was in trade school we had a fellow come in who was well versed in fireplaces and masonry heaters. in the course of his presentations he talked about the 2 different types of brick and how the clay used for the buff coloured bricks didn't contain near as much iron oxide and had we noticed that firebrick were always a buff colour.

Perhaps the brick manufacturer you mentioned only have a buff coloured clay and add iron oxide to get a typical red coloured brick, I don't know. But I do know there are 2 basic different clays, I also know that the red is much more common and also quite a bit cheaper because it's more common. Like I say, i will try to get pictures and post them.

Regardless, if a buff coloured brick was used to obtain brick dust then it could be used for typical mortar making but if a red coloured brick is used it couldn't be unless it was for a red or darker coloured joint
 
#105 ·
Regardless, the mineral content, not the visible color of the clay body determines the vitrified color. In regards to the color of the brick dust used in stucco/mortar it will be the color of the finished product. Red bricks give a pinkish or orangish hue, buff will give a yellow tint.
 
#110 ·
The only reason I mentioned the titanium oxides was the one time we did a job that involved yellow I mean YELLOW joints we used a dye from Ferox and reading the bag i saw that it was basically titanium oxide.

Like i say, i have minor experience with grey clays and have seen the brick that it produces. And as i say, it was mentioned by this fireplace/masonry heater mason that was teaching us fireplace theory, about the lower iron oxide content that the buff brick contained.
 
#112 ·
"1000*C seemed to be the point that C3S was developed rather than C2S."

Yes, although I think modern cement kilns get considerably hotter than that. For clarity, what you call C2S I know as belite and alite is C3S.

"At what proportion to the lime would give a compressive strength in and around 400psi? NHL is pretty much unavailable here and i don't do near enough resto to bring it in myself, but if I could get a few dozen bags of this metakaolin it may do me for a while. I'm assuming it doesn't go off on it's own from moisture? "
It is pretty stable.
It requires the CaOH in order to become reactive? Any change in the mixes appearance using it?"
None, since it is white.

Even though I have metakaolin, I usually use NHL since it is available about 2 mi from my house. You might be able to get some NHL samples to use as references to figure out your compressive strengths. That is what I may do this spring since I have a white stucco job. 400 psi is pretty soft. You will exceed that in 6 months at around 2:1 aggregate/binder with NHL 2.
 
#114 ·
Not to get into the materials used for getting plasticity and workability in mortar, this information may help.

The color of the clay that is used to make brick can be changed quite a bit by the firing process that changes the chemistry depending on the very high firing temperature. All the iron in a clay can be modified by temperature.

When it comes to mortar colors, the only good and permanent colors (not "dyes") are iron oxides than can be anywhere from yellow to tan, red or black and are modified during the processing temperatures. They are more costly. Carbon blacks are just "soot" that is embedded in the cementiteous material and will erode and wear away over time. They are cheap and that is why they are used to give a quick, dark color initially.

Other real pigments are chrome oxides (very, very pricey and strong for pigmenting concrete) and titanium, which is very commonly used in white paint, but not too effective in concrete because of the cost and the influence of the aggregates.

Dyes are usually just the cheap aniline materials that do not have permanence in concrete materials and are not used in real permanent concrete.
 
#116 ·
Dom-mas, have you seen these pics:

http://brokebrick.com/brickyard.htm

The low-fired brick (mainly pallets and trash are burned)) are bright pink to bright buff depending up where they are located in the kiln (clamp). The clay body is grey-brown. The only clay that I know of that fires "true" is highly refractory clay which is mainly yellow/gray and fires yellow. It can and is often changed by additives though.
 
#118 ·
well i will guess that it's from "buff"alo (bison) hides.

The clay that mexican fellow is using is similar to the clay but quite a bit more yellow than the clay that I am thinking of. Some of the brick that I saw was however the same colour as the brick that I am thinking of. So a yellow clay can produce a grey or a reddish brick depending on where in the kiln it's fired. I think that's what you're saying.
 
#119 ·
Where simply determines the temp in that situation. My only real point is that initial clay body color is not really indicative of final brick color, and thus color can alone can not be used to determine a firing temp without a lot more information. Originally we were talking about which brick dust would make a good gauge material, and color is not the primary determinant of a good one.
 
#120 ·
Well, not exactly. My question about the buff or red brick dust was about the colour it would give a mix. Rogerhattam had said that the brickdust he used coloured the mix slightly, so my thought was that a grey or buff brick dust at 10% of the lime wouldn't effect the colour in most work that I do. A red dust would unless the joints were either red or darker than red. I guess this has brought up the question of whether a red brick dust will act the same as a grey/buff brick dust.

I really think i'll stick with 1:2:9 mix or try to find some metakaolin. This brickdust stuff is too confusing unless it's speced.

I do find it very interesting though that fairly different brick colours can be achieved from the same clay depending on temperatures. I've always known about clinkers and Salmons but that's about it.
 
#121 ·
I see, well I have done some lime mixes with buff and red brick dust and it definitely affects the color. The red makes a pastel pink and the buff gives an ivory, just as you would expect. Which one is better for the mix, I do not know. The pink sample has been hanging on my fence for 5+ years though, and while hard can still be scratched with a fingernail, although it does not dust. The ivory sample I can't find, so it was probably trashed years ago.
 
#122 ·
mortar

I have away for a week, this discussion is real interesting. I started burning brick as a hobby a couple years ago. I use a scove klin or clamp as it was called in COLONIAL WILLIAMSBURG. Used coal,soft & hard,along with oak,hickory and ash for fuel. Tried several clay deposits,the color of clay does not effect final color.Have used blue/gray clay along with tan clays. If any of you guys are interested a free book can be read called 60 YRS.A BRICKMAKER by A guy called CRARY. HE was born in i believe 1814 & wrote the book in the 1890s very fon read. Or type in WILDCATBRICKCO he has a link to that book it is free & complete on computer. I have to admit my computer skills are the closest thing to non existent or i would show pictures.
 
#126 · (Edited)
To sum it all up

Gentlemen,

After reading the smeaton project findings and following your discussion - I will be parging a stone and mortar basement (circa 1914) soon. I planned to use either a type N or a homemade type O (no one seems to sell a premade one) by adding 1 part type S hyrdrated lime by volume to the off the shelf Type N cement mortar and of course sand. Since I am working on the inside on a natural stone (appears to be limestone) I am not concerned with excessive compressive strength, and since the existing mortar is in relatively good shape (i.e., not a repointing job), will not be exposed to the elements or any freeze-thaw action, my primary concern is vapour permeance and then durability.

Will a type N (1:1:6) or type 0 (1:2:9) (c:l:s) mortar have enough permeance to avoid the often discussed problem of trapping water in the wall?

The other side of the wall is (unseen) but likely not dampproofed.

Thanks in advance for any help.

I have talked to a couple masons on different sites and they look at me like I have two heads when I mention lime mortar; both have recommended type s with an admixture to increase adhesion. Is it possible that given the sheltered relatively good shape, that something more durable like a portland sand mortar would be good enough?

sorry for all the questions
 
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