Score the bottom edge of the side slab. On the side that will be the interior surface of the finished pot, score the interior surface along the two side edges. Using your sumi brush, lightly brush a line of slurry along the scoring on one edge on the base slab. Gently set the side slab upright into the slurried scoring.
Working at this size, the side slab should be able to hold itself upright, but in case it wants to slump you can support it with any handy object.
Roll out a tiny coil, about 1/16 inch in diameter. Position it along and into the interior corner formed between the base and side slabs. Using the rounded end of your wooden tool, lightly press and weld the coil to both the base and side slabs. Leave any remaining length of the coil attached and loose.
Repeat this step with the second side slab, making sure that you are scoring the interior surface.