Judy,

The operative phrase in my comment was that we "had it done", because it takes 
some significant expertise to get this right and some impressively costly 
equipment. As for mortar analysis being a "crock", I think I recognize that 
description - isn't it a technical term used by Boston masons when they are 
feeling unusually polite? (Which I'm sure they always are in your presence, 
not that they would ever have cause to question anything you tell them.) 

Actually, an honest petrographer will be candid about the assumptions that go 
into the typical analysis, which can be considerable. But if they know 
something about the background of what they are being asked to analyze, and 
some history, and something more than portland cement, silica sand and lime, 
it can help them avoid some of the pitfalls associated with assumptions.

On the other hand, there is just no excuse for mistaking gypsum plaster for 
lime, and on a 1920's building you should be smart enough to be looking for 
gypsum in the first place. Mortar analysis becomes a crock when it's limited 
to acid digestion and a good dose of Py's special organic bull-derived mortar 
admixture.

Mike E

---------- Original Message -----------
From: "Judith E. Selwyn" <[log in to unmask]>
To: "edison" <[log in to unmask]>
Sent: Fri, 13 Apr 2007 12:18:29 -0400
Subject: Re: [BP] Plaster consolidation

> Andy doing mortar analysis?
> 
> Unfortunately, most all (all !!) of this mortar analysis is a crock -
>  and it's hard to explain to those who want "analysis" that they are 
> getting the emperor's new clothes.
> 
> Do you do Mortar analysis!!
> 

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