Jim Stewart wrote:
Harold & Susan Vordos wrote:

I'm not nuts about the appearance of concrete, so when we built the current
shop, I chose to dye the concrete instead of paint it. I use a generous
amount of Oil-Dri, so my floor stays very clean, not oily. I also have a
built in vacuum cleaner system so it doesn't get dusty.

Did you use a purpose-build vacuum or a modified shop-vac?
I've been thinking about running 3" PVC around and connecting
it to a shop-vac in the loft. Do you know if there's a place
to get adapters to make something like this work? It probably
wouldn't be a big deal to turn adapters on the lathe if they
aren't readily available.

3" is too large I suspect.
You need to keep flow velocity up, so that sand particles (or worse, metal
filings) don't fall to the bottom of the pipe and clog it.