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Post by DCish on Sept 1, 2014 5:57:09 GMT -8
Hmmm... so I could take last winter's wood ash, drain water through it to get lye, and use that water to make my clay slurry, and presto, geopolymer?
What do you think of mixing in wood ash directly with the clay as Donkey mentions in one of his threads, could that have a similar effect? If so it would be preferable to skip the step of making and mixing in caustic lye.
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Post by Deleted on Sept 1, 2014 6:32:20 GMT -8
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Post by DCish on Sept 1, 2014 8:19:22 GMT -8
Very exciting! What PH value would I be looking for in the concentrate?
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Post by Deleted on Sept 1, 2014 8:29:50 GMT -8
The highest PH value of 14 is already reached at a relatively low potassium content, thus the PH value does not really tell much about how caustic something is, but it tells if something is dangerous. How caustic the concentrate will be depends on the amount of water remaining.
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Post by Deleted on Sept 1, 2014 8:44:59 GMT -8
Geopolymer can be foamed by mixing in ordinary dishwashing liquid and then mixing in something that produces gas with water. Needs to be done with care, do not use too much of each. Very lightweight foam needs a more advanced foaming agent.
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Post by photoman290 on Sept 1, 2014 10:27:31 GMT -8
karl i have been offered some 1-3mm zeolite for a good price. would this be suitable for using as aggregate in place of the 0.7-1mm grade. i can get both but the 1-3mm is a lot cheaper.
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Post by Deleted on Sept 1, 2014 11:21:51 GMT -8
Depends also on the binder. 1-3 mm requires more binder between the particles than 0.7-1 mm, as there will be more space between the particles. Metakaolin like argical m 1000 will be more sensitive in this respect than grog. Like with wood glue, thinner is better.
A mixture of several aggregate sizes is usually the best.
Small particles are better with respect to low heat conduction. Even a mixture of two materials with equal heat conduction will result in a reduction of heat conduction, just because lots of thermal boundaries will have to be crossed with small particles.
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Post by photoman290 on Sept 1, 2014 11:42:54 GMT -8
ok that makes sense. will go for the 07-1mm then.
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Post by DCish on Sept 1, 2014 12:18:18 GMT -8
Oh. Is there a way to know when the right amount of potassium is present (when enough water has been driven off)? Is the old soapmaking test of "concentrate until an egg floats high enough to show an inch-diameter portion of the egg above the surface" applicable here?
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Post by Deleted on Sept 2, 2014 2:12:57 GMT -8
You can test the concentrate by dipping of a piece aluminum foil. Strong concentrate will eat the foil in a short time. Once the concentrate can eat glass you have got it very strong.
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Post by DCish on Sept 2, 2014 6:15:11 GMT -8
Thank you. And am I right to guess that the stronger the lye the stronger the resulting brick, up to some point of diminishing returns? Thus the path forward would be to experiment a few times until I get the strength I want?
Also, clearly metal and glass are no good as containers for this. The soap making site I was reading recommended plastic containers rated at 5 or below. Does this sound like an accurate indicator?
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Post by Deleted on Sept 2, 2014 6:30:41 GMT -8
Your assumptions are correct.
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Post by DCish on Sept 2, 2014 8:46:48 GMT -8
Great, thank you
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Post by Deleted on Sept 3, 2014 10:15:36 GMT -8
photoman290 has kindly provided me with a sample of metastar 501 and some more argical m 1000 and molochite 200.
Aside of the color metastar 501 and argical m 1000 have no difference recognizable for human senses.
Both have a high water demand resulting in a high volume. Fine grog can be boosted to higher volume too, by waiting for geling and then add more water. resulting in similar density and strength. Metakaolin needs obviously an additional source of dissolvable or dissolved silicate to get higher density and thus higher strength.
The density and strength of metakaolin geopolymer with additional silica will not differ much from density and strength of grog geopolymer.
Slurries can be blown up a bit by mixing in baking soda. Does not loose as much strength in this way as if volume is enhanced by just more water.
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Post by photoman290 on Sept 3, 2014 13:41:15 GMT -8
argical m1000 is both a lot cheaper,about 1/2 the price of metastar 501, and a lot easier to find. i got mine from chalkdown lime in the UK, but anyone doing lime rendering and renovation work should carry it.
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