>     (ruling out historically tinted mortars)
>
> When 19th century builders colored the mortar to bring out colors in 
> the surrounding masonry, did they color the entire batch?     Or is it 
> only the first inch or two?
>
c,

It takes extra work to repoint the outer portion of brickwork on a large 
building, say the B & N bldg. at Union Square w/ the steam pressed brick 
and very thin "Coney Island" butter joints. The mortar there, in 
different colors for different portions of the architecture and for 
different materials of the facade, was tinted through and through. My 
feeling is that this was the prevalent trade practice. But I have also 
seen evidence of walls built with an untinted mortar then followed up 
with a tinted top pointing. It would likely be work where more expense 
and care was intended and les focused on optimal production in the 
building process. So there is no exact yes-no answer to your question. 
As our esteemed Mr. Edision has pointed out one needs to look at the 
forensic evidence of the structure. Problem is getting to see into the 
wall, which is where probes come in handy.

FYI there is a point where the percentage of tint to mortar begins to 
have what is considered an adverse effect on the strength of the mortar. 
I do not remember where that point is at... seem to remember people 
arguing over if it as 10% or 15%. For the most part I don't need to 
worry about it. As to mortar analysis I suspect that it is nearly 
impossible, certainly impractical, to determine what the proportion of 
tint is within an existing mortar. When one wants to match to an 
existing color of tinted mortar it is partly through trial and error, 
science and art. Note that I did not include bull crap in that recipe.

][<

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