Metal Casting Zone

I'm looking for sand for my first foundry project. That means I'm looking for sand to make my refractory material and for making green sand. So my questions are:
Does Lowes carry any good sand for this? (like the play sand)

Also, none of the sand they carry has a "grit rating" on it? (whether it's 60 grit or 120 grit)

And finally, what is the difference between grit and mesh sizes? I know this is a lot, but I just want to make sure that I do this right. Thanks in advance!

I purchased my sand from home depo, I dont think the play sand will work for you because it is not silica based. make sure the sand is silica based. They should have sand for makeing up mortar, it will work out just fine.

I bought some from Lowes... but it had very large chunks of *stuff* in it. It was the all purpose quik-crete sand. Maybe this will work for the refractory, but what about for making green sand?

no will not be good....there should be bags that say fine sand some where around there.

And this will be good for refractory and green sand?

Its been working out good for me, getting the moisture content right in the green sand takes a bit of trial and error, but i got it down pretty well now.

Do the castings come out ruff or fairly smooth?
This guy says use 120 grit (http://www.foundry101.com/archive.htm) ... but none of the sands in the store are marked by grit size.

no unfortunately not real smooth, not bad though. Your best bet for a smooth casting and for ease of use when starting out might be oil bonded sand. green sand can be a bit of an art when just starting out. Green sand has to be just right, right amount of water, right amount of clay, it takes a bit of practice to get it just right. One little trick I did learn when useing green sand is to let the mold sit in the sun for a little bit before you pour, it dries it out a little bit and cuts down on the holes.

I and the kids just got back from town. Absolutely no one has sand. Lowes = Zilch, Home Depot = Nada, Ace Hardware = Goose Egg ... no one. It's all purpose coarse grain sand. I even stopped by a Stone and aggregate seller and they didn't have any either.

What gives? Is there something I'm not seeing?

Home depo should have it, its in the aisle where the cement is in a plain brown bag.