http://www.potterswithoutborders.com/video/Rwanda_Water_Filter_Project_2010.mp4
]]>I think to test how much water the sample holds (porosity) one would take, as you say, samples of the same volume weighed before and after saturation, the difference in weight being the amount of water absorbed by the sample. from this information we would be able to derive the volume of empty space in the sample.
If the test were done by original weight vs. saturated weight independent of the samples volume the test results would certainly be compromised.
]]>As described your samples will all be different volumes, and the ones with more sawdust will be larger than the ones with less sawdust., this will throw your porosity results with the larger samples by volume holding more water regardless of the porosity of the sample.
]]>This is a link to a little descriptive video that Ben Morrill of
Potters Without Borders put up showing Barry Cawston and Art Gavel two
excellent mechanic/machinists who have volunteered to work on
modifications to the Dutch designed press.
It takes a while to download but you can see some interesting details of
the press as it is emerging-
It will also disabuse any of the life of a potter-The workshop has been
turned into a machine shop for the duration-At the end you can see Isao
Sanami/Morrill and me trying out the lever mechanism- it hasn’t been
greased the arm is not yet installed nor have the bearing gibs been
properly set but you can see the action clearly- Send us any comments
you have.
Here is the direct link:
http://video.google.ca/videoplay?docid=-3770635621016989483
Thanks Barry, Thanks Art They have both already invested weeks of work
deliberating about the process, building the press and putting up with me!
Thanks Ben for documenting this- More to come
Burt
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