Always store domes on their rims. Trim the rims if they are uneven, and make both halves the same size. Create slip clay on the rims of the domes by scoring them with a forkand brushing water on them. Repeat as needed. Assemble the two halves.
Proper alignment is very important.
Fill in and smooth the joint area. Cut a dime-sized vent vent hole about 1 inch above the joint line. Roll some of the left-over clay into a cylinder about 1 to 2 inches long and approximately the size of a hotdog in diameter. For more information contact Bill Kilbourn .