[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

GSBN:pH of Clay Lime and VP

Although posted to SB-r-us, I thought some of this might be relevant to some of the GSBN members not on that list.

BTW, couple of other things about lime and clay. The first addresses Paul's comments about testing for pH. It would seem that the easiest solution would be the pH sticks suggested the other day by Elizabeth Hogan who as a lab rat suggested that she had access to ones that would read reliably higher pH values. I wrote her asking for more info and haven't heard back yet. The other option would be to purchase one of the $65 meters that Harry spoke of and then pass it around between a group of people who could conduct testing on the soils that they will be using. Everybody using it could contribute to the initial cost. One more thing has to do with the vapor permeability of the clay/lime combination. Or maybe I should say "breathability" just to rib at Paul. Harry didn't seem to have any data on this so I wrote John Straube yesterday asking if there were any opportunities coming up where some samples might be tested. Throw in water absorption for that matter.


On Wednesday, January 22, 2003, at 06:13 AM, Paul Lacinski wrote:

Bob, David,

I'm pretty sure you can arrive at the proper mix empirically, because
the I think the consistency of the plaster changes dramatically when
the percentage of lime gets to where it needs to be.  (I posted about
this a week or two ago.)  Here's how I would approach it- get your
usual mix going, ideally in a mortar mixer.  Make it a little wetter
than usual.  Then start adding lime.  (You may need to add water as
you go.)  At some point, the mixture will stiffen dramatically- much
more than can be explained by the lime absorbing water.  It will also
feel sort of greasy.  You can then add some more water and sand and
straw, whatever amount seems appropriate to the increased volume of
binder.  I think you will find this plaster has something of a
gel-like feeling to it, when compared to a straight clay or straight
lime plaster.  This is how we have been making lime stabilized
plasters for three years now, and they are quite solid and weather
resistant, and show very minimal cracking.

If someone who is actually plastering this time of year (it's 1F -18C
with a stiff wind here this morning) would be willing to test this
mix for pH and let us all know whether it actually meets Harry's
tests, that would be a great help.


Paul Lacinski
Amy Klippenstein
GreenSpace Collaborative
Sidehill Farm
PO Box 107
463 Main St.
Ashfield, MA 01330 USA

To unsubscribe from this group, send an email to:

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

Athena & Bill Steen
The Canelo Project
HC1 Box 324
Canelo/Elgin, AZ 85611