FOLLOW-UP: This video from Team Saint covers a few extra tips for HDPE cutting. the blade being used here will likely be too big for many cuts necessary, especially at lower weight classes, but the saw featured could be a suitable replacement for a circular saw if you don't have one as it can do long cuts reasonably straight. As well as that, this team knows their stuff with this material, so it may be interesting for anyone seeking to go against Carbide in the future: