dark room rookie;
yes it is and the messy looking silicon sealant prevents turbulence from the paper channels. It was a learn by doing process and the drum works well for both black and white or color. I couldn't find any ABS tubing less than 1/4 in thick and that was just too heavy for me and the ABS caps fit very tight and were hard to remove and they still leaked, so I used PVC and develop under safelight which poses no hardship and the PVC cap fits more precisely and does not leak. The PVC tubing is also available in 10in and 12in and would make tubes capable of print widths of 30 and 40 inch and more.
Denise Libby