Cut a circular piece of plywood to fit inside the lid of the largest tin to form a sturdy base.
Using a compass, find the center of each tin, the lid, and the plywood piece. Drill holes into the centers of all the pieces large enough to fit the threaded rod.
Put the plywood into the tin lid and place it onto the threaded rod, securing it with a washer and nut on the bottom.
Thread on a nut a few inches above from the base and add the largest tin. Repeat for the two other tins.
Adjust the heights of the tins to accommodate easy access to their contents. Mark the threaded rod inside the top tin, allowing an extra 3/4 inch for a washer and nut. Cut the threaded rod to this measurement with a hacksaw. File any sharp edges.
Measure the distances between the tins to determine the lengths for the copper pipe. Using a pipe cutter, cut the copper pipe into sections using these measurements.
Disassemble the stand, place the sections of copper pipe over the exposed threaded rod, and reassemble the stand.