Have you ever ended up paying a high-wage carpenter to spend time scraping old masking tape off of a painted window? It's not exactly an efficient use of resources. Next time, try using Cantech's 7-Day Outdoor Masking Tape, which the manufacturer claims will pull away from glass without leaving a residue, even after seven days of exposure to direct sunlight. The tape is available in widths from 12mm (about 1/2 inch) to 72mm (27/8 inch) so it will work in applications from brush work to spraying. Contact: Cantech Industries, P.O. Box 1432, Johnson City, TN 37605; 800/654-3947. Pipe Slope Level How do you set a drain line at the required 2% slope? If you are considering investing in an electronic