DL, are you using 100% clay for the bricks? Or lighten them up with sand, straw or wood chips?
1: I have used a mixer on the end of a 1/2" drill, same as used in the drywall business for mixing compound in the 5 gallon buckets. On a small scale use 5 gallon buckets larger scale use garbage cans or an old bath tub. Raw clay, not dried and pounded to a power, it is nice if it can sit in a pile for a year for frost action to break it up a little. Place the clay in the tub and let it sit for a while, overnight if possible and go at it with the beater. Wipe it into a cake like batter or even a little more thinner like paint. For light clay and straw you should be able to stick your finger in the clay slip and just make out your finger print. You can always add more water or clay to gain the right mixture. Screen the slip before you use it, to filter out the unwanted grit, just pour the slip through the 1/4" screen into a fresh container.
2: Having no experience in clay brick and clay mortar, my guess would be a sand and clay mixed mortar. I would also be curious how a lime mortar would function?
One of the functions of lime mortar is it is the weak link with the older bricks the mortar will fail before the brick, for it is softer, allowing things to move a bit, then reheal. Where if you use a modern mortar which is harder in combination with the older brick the brick will fail which is not so good. If using lime as the mortar for you clay brick would the brick fail as they could be softer than the lime mortar? I take it that your brick will be unfired.
3: I have seen, at Fox Maple, where they used a rabbit cut into the face of the post to form a key for the clay infilled walls, in hopes to stop the draft. I would use such a technique to try to stop or slow the air movement at the post. I'm not sure of the size of the key, 1"x1" perhaps and maybe with a chain saw.
One of the draw backs to clay is it has to fit into a time line to allow the clay to dry before frost can harm the undry wall. Brick made in the spare time allow the wall to be built with a wider window. Probably not in mid winter.
I like this stuff too.
Tim
