>Does this mean we  can 
> choose the coatings, or does it mean you (or your other friends with 
> the  Mr. Wizard chemistry sets) can custom tailor them for us? 

Ideally, you could get permeability performance data from the respective 
manufacturers product data sheets, but then the stated difference from one 
manufacturer's product to the next may have more to do with test methods and 
reproducibility than actual differences in product permeability. 

SWR is on the right track with a unified testing program using one lab, but 
only a handful of products have been tested and validated so far. Within a 
single manufacturer's product line, it can be useful to compare permeability 
of various products, because the data may at least reflect some order of 
relative permeability. 

Paint formulation is complicated, and I don't think it is feasible to custom-
match permeabilities in the same matter-of-fact manner that we tint custom 
colors. But a diverse product line should include products with varying levels 
of permeability (along with a bunch of other important properties), and this 
should provide some options in fitting the product to the needs of the 
particular project.
 
>>Mike, sometimes it  isn't easy 
>> to tell what your personal views are, in comparison to your  
>> professional opinions.
> 
Are those necessarily mutually exclusive categories? Shouldn't the same values 
apply? If you're about seeking truth technically and professionally, aren't 
you likely to be personally disgusted by transparent efforts to distort the 
truth for personal gain?

Mike E. 

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