Each spring, after the harvest season ends, the holes dry up as the tissue around each hole dies. Over the course of years, the tree covers over the old hole with new wood, leaving a slight scar on the outer bark. They are drilled at a slightly upward slant to insure that the sap will flow down out of the hole, through the spile, into the bucket. While buckets hanging from trees is an effective means of collecting sap, we find the tubing system of collection to be more efficient. Plastic spiles, replace the wood and metal ones.
Plastic tubing replaces the buckets.
Many branch lines will feed into a mainline, over its course down the slope to large collection or holding tanks. Tubing systems may be vented or closed. Systems without much natural slope may use vents, letting air in at each spile, to help prevent vapor locks which inhibit flow through the tubing. With sufficient slope, closed systems, such as we use, provide greater sap yields through the creation of natural or artificial vacuums. . . . A picture of a maple tree showing a tap and tubing One last feature of the tubing system worth noting is the use of drop lines.