Nice! Footnote 9 is confusingly worded. And it would be nice it there were more plywood types selectable. (In case you know the programmer)

Thanks. Makes sense to me (and I imagine the mortar probably suffers even worse than the bricks).

I have no expertise in masonry. But my instinct is that paint penetrates deep into bricks due to their semi-porous nature. Is that the reason for the permanence?

Laundry room? My immediate thought was wet area + MDF = warping/swelling/etc. But Pioneer’s answer seems better informed.

Have a great weekend. I’ll be trying to make a 6x8 array of very small holes in glass using hydrofluoric acid, 600 grit garnet, and gentle drilling. So…much cursing, probable lung damage, and quite possibly my garage declared uninhabitable. Hope you have something similarly fun planned!

Thanks for the thoughtful response. My original comment was really suggesting waterjet. Probably should have left the EDM out. I get the sense you feel your trade was undervalued - and that was not my intention at all. I have the highest respect.

Then I stand corrected.

Edit: I’ve had parts made by wire EDM (cutting dies), and had very high aspect ratio holes (50:1 or so) drilled by EDM. But never sinker, which is a truly fascinating process. You do any of that?

Totally agree. But if the shafts were 40mm, it would be money very well spent.

I used to know of a shop with a waterjet that would take small jobs on the weekends. If you could find something like that… Or wire EDM. Less heat damage. But 12mm? I’d use the grinder with the excellent tips already mentioned.

Curious - is it a 3d printing process with abrasive materials involved? Like SLS? Those shafts won’t see much force. HRC50 I think you could use a cold saw.