We’ve made 15 bricks with our CEB Press so far. We’ve tried a few different mixes:
first layer clay soil only
first layer clay soil only with 2 quarts water per 5 gallons of soil
Note that we’ve been in a pretty serious drought lately, so the soil is all very dry. The subsoil was more moist than the first layer of clay. The subsoil started about 2 ft down and was more red in color than the first layer.
All of the bricks have minor cracks in them, though the ones with added water are worst, as are the ones which were dried in the sun. One of the first layer clay only bricks was dropped from increasingly higher distances until it broke in half at a 5ft fall after 2 days of curing. It appeared to be more dry on the outside surface than on the inside, which leads me to believe
that it would have been even stronger had it cured for longer.
The shaker motor was tested and seems to shake the machine quite well. Still need to work on the controller board to get all solenoids operable and automatic.
I looked into buying a Power Cube for the work party, but it doesn’t seem like it will be able to be manufactured in time. On the other hand, we may get away with renting only one tractor which will both till and load soil into the CEB hopper. That leaves Danny’s parents’ tracktor to power the CEB press. However, the CEB press could benefit from faster gpm flow as the tractor we have is only 14 gpm compared to the rental units which can do 30 gpm. This would speed up brick making by about 2x. If we have many people out to help, this could significantly improve the efficiency of the operation, and may be worth the extra cost. On days when the CEB Press was not the bottleneck, Danny’s parents’ tractor could be used to power the CEB. The efficiency of construction with CEB blocks seems to be reliant on how to make sure that every step in chain from digging soil out of the ground to setting into the wall is happening at the same pace. If one step is slow, it will slow down all of the rest.
It would be nice to have a power source for the CEB in general, so we don’t always have to bring danny’s tractor down in order to use it. If someone else around town wanted to use the CEB press, then it would be much easier to loan them the press and power cube, but not danny’s tractor. They could also be instructed to rent machine X from the rental place … 5x 1 week rentals = cost of power cube