Try original formula again.

Every sample in the previous test was a flop.  They either crumbled when dried or after firing.

So time to work from the last know good.   Today I made up what I think is the formula used on the good brick.  Originally I was going to do without the perlite but went to far with the water. (I should know enough to hold back some of the dry ingredient mix) and added 8 oz of perlite.   This was perlite sifted through a crank type flour sifter. 

This is also an attempt to see if I can do this in cold weather.   The first day will have to be in the house.  If the forms were not wood I could let them cure in the heated wet freezer chest.    Tomorrow afternoon I will remove them and transfer the samples.

My intended formula was

10 : Silica Flour
  6 : Native Clay
  2 : Portland cement
  3 : Lime
  5 : Perlite

And I ended up with 8 Perlite.   Tomorrow I will make sample with 0, 2 perlite and I expect they maybe short bricks.(did not happen)

To make the bricks easier to release I glued vinyl to the bottom and used a light film of crisco on the bottom and packing tape covered sides.

Thinking about doing the zero perlite yet tonight.   hmmm  OK going for it.   Mixed up a 1.5X batch to ensure I get a full brick and have dry to hold back.  Going to start weighting the water if I remember when I get out there.  The mix is currently doing 15 or 20 minutes in the mixer.

OK that is done and worked well.  Think I used 12 OZ in 2 lbs of dry mix.(WRONG)  Need to check the check marks I made.

EDIT: Used a 2 oz cup and made 7 check marks which is 14 dry oz of water for this 1.5X batch.   For a 1X batch use 2/3(14) or 9.3 oz.    A fluid oz is too close to one avoirdupois aka weight oz to matter. So they should be interchangeable.  The dry weight of the mix without water came out to some even number of lbs, I think 5 but that sounds too high.  No lost info since we have the exact formula for the ingediants.


Now to make sure they do not dry out while they are in the forms aka molds.