Im building my box and I am going to have the HDPE countersunk into a piece of plywood which is then on top of the box myself. Is it necessary to have coping and if it is what should I use since I cant weld and use metal. Also, should I take off the HDPE during the summer to stop the warping?
my friend has 4 boxes done exactly as you described and they all shit the bed within 2 seasons from normal use.
Angle iron with beveled edges will help keep the boxes together, no burs in the HDPE, and make em easier to pretzel and hold an edge. plus it isnt THAT expensive. I would highly suggest it.