Wes fired this volley in
:


The Forstner likely would be better. I may just order a forstner bit.
McMaster has HSS or carbide edged, which would you choose?

HSS will last for hundreds of holes in natural HDPE, but carbide is
better in the black material -- some of the pigment particles are large
enough to be abrasive.

There's an outfit up the road from us that will make any sized Forstner
for you custom. I've seen such on-line, too. They're only marginally
more expensive than top-of-the line bits in standard sizes.

LLoyd