# Sand weight vs volume

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I'm filling something with sand so I can easily calculate the volume.
But the store sells sand by weight, not volume. I have no idea what the
density of sand. What volume of sand is in a hundred pound bag? 10
gallons? 50?
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Dry sand is about 100 lb/cu.ft. or about 13 lb/gallon. It varies surprisingly little with seive size.
PhysicsGenius wrote:
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Hmmm...if I filled a container with sand, it would sink in water, so it's more dense than water, which is a 1 pint = 1 pound. Therefore a gallon of sand weighs more than 8 lb. Call it 10, then a 100 lb bag would just be 10 gallons.
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I just about blew a gasket on how much this was going to cost me when I realized I'd done my volume calculation wrong. It's still more than I thought, but it won't break the bank.
Thanks!
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What kind of sand are you talking about? I just bought 30 bags of AFS60 for \$1.75 a bag. That is about as high a quality silica sand as you can get.
(Yes, fellas, I finally got my nerve up. We are ramming up the mold for the 5,000 pound keel fin just after Christmas. )
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I'm doing the Gingery projects. Right now, just the furnace, so I don't need the high-grit stuff. As I was driving to the store, I realized that I might even be able to use the free sand my town gives away for driveways, though I'll have to check if a) it has salt in it and b) it is safe at high temperatures.
Anyway, the book says that for molding, you want "75 mesh to 125 mesh". I just got back from the masonry supply place (to buy fireclay, I finally found it!) and I asked while I was there what grits they had of silica sand. "Medium and extra fine". OK, but what numbers are they? "20 and 45".
So I'm not really sure WHAT I need. What is "AFS60"? What units were "20 and 45" in? How do I compare that to "75 to 125 mesh"? Where can I get sand for cheaper than \$20/100 lb?
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Most of the cost of sand is the packaging. If you've got access to a pickup, go buy bulk at the local sand and gravel company. When I built a new brick walk a couple years back, we filled the back of my neighbor's Toyota pickup (~1200# - probably more than we should have put in, we drove home real carefully) and they charged us ~\$25. That many bags would have been ~\$150.
Jim
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don't
AFS is the American Foundrymen's Society grading system. 60 is the number of wires per inch in the last sieve it went through so it is smaller than 1/60" and larger than 1/70". Sand raanges from #10 sieve to #200 sieve. Builder's sand is less carefully graded and is supposed to have has less 15-20% smaller than 50 sieve with the majority in the 40-50 range. The really fine foundry sands are from 70 to 150 and anything above 200 is a clay or silt. Without seeing it, I would venture that "extra fine" is probably a mix called "plus 70" which would be everything that passes the 70 sieve up to about 150. It would make a fairly good base for a molding sand. The "medium is probably closer to builder's sand and is probably better for cement.
When you are mixing up a sand/cement/fire clay mortar, you don't want a lot of fines in the sand. They just take up the voids that the cement and fireclay are supposed to go into.
Where are you? Lower Manhattan? You need to keep looking. Surely you can find some good servicable sand for less than half that price. Maybe I am just lucky to live on the Fall Line where some of the best silica sand deposits in the world are. My price was for bags picked up at the pit.
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Do you know what the "20 and 45" might have been then? That would be some pretty rough "extra fine" sand. Or maybe that's relative to the brick and tile they normally sell.
Good point, plus I imagine the fine sands are more expensive. I'll only use the high mesh stuff for molding.
This was a tile place and it had a bunch of really nice mosaics in the showroom. Probably the price is jacked up for Trading Spaces fans. (The fireclay was \$16 for 50#) However, I haven't even been able to find sand at Home Depot, no kidding. I guess I'll try the lumber yard. "Silica sand" is just regular sand, right? Shouldn't I be able to find that pretty much anywhere?
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Verbal terminology is always subjective. "Fine" to a tile setter would be "'bout right" to a brick mason and boulders to a foundryman.
As you were in a tile store, I am going to guess that 20 sieve is used for "scratch coat" mortar. That is the first rough layer put down when bedding tile. It is used to level up the area aand provide a good base. The 45 would be used for the setting mortar that goes over the scratch coat and the tiles set into. In setting thick floor tiles terracota and bluestone it is also used in the grout. The joints in bathroom tile are filled with tile grout which is usually a premix of white fines and a gypsum based cement.
You could probably get by with the 45 but it is also graded move evenly than you want. A good mortar sand is a mix centered around 40 sieve with a spread from about 20 to 60 sieve. That will produce the densest mix with the cement. It is also a LOT cheaper.
Keep in mind that it has been 30 years since I took mud lab and this is about all I remember from 3 quarters. :-)
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Sand blasting sand (silica) might be cheaper. I recall paying about \$5 (Canadian) for a 50 pound bag of silica (my molding sand).
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Yeah, that's what I figured. Good thing I asked for a numerical answer after she said "medium" and "extra fine". Sheesh.
Still \$20/100 lb at that store, though. I'll check around and see if other places have it cheaper. As I said before, my town gives away free sand in the winter--maybe I can use that stuff.
I don't know a thing about this stuff--who knew sand could be so complicated. Thanks a bunch!
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At the risk of continuing to be a PIA, doesn't the *diameter* of the wires play a role in that?
Maybe 60 mesh really means that the wires have 1/60 of an inch of open space between them, and thus there's *fewer* than 60 of them per inch?
Happy Holidays,
Jeff
-- Jeff Wisnia (W1BSV + Brass Rat '57 EE)
"If you can keep smiling when things go wrong, you've thought of someone to place the blame on."
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Like I said, it has been 30 years since I took my last mud lab course. I knew that was wrong as soon as I hit send. When you get into the finer sieves the wires in the sieve take approximately 40% of the space. A #70 sieve would have .006 dia. wire spaced at .0143" and have .0082 openings.
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Where would I find something like that?
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I buy F100 Olivine sand in 100# bags and it fills two 5, gallon buckets to the top edge. I would have to say it all depends on the type sand and its mesh size. Visit my website:
expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy.
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IIRC, a cubic yard of sand weighs over 2200 pounds, depending on moisture content.
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Freight and packaging does have a lot to do with the cost of sand. I live a mile from an open pit sand mine, and I can drive over and get a 4 ton scoop or less of anything they've got for \$10, that's a minimum purchase price to them.
RJ
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We have two kinds of pits around here. The pits operated on the East side of town by the ready mix plants sell "washed and graded" in bulk. It is basically a builder's sand with grain sizes running mostly from 20 to 60. My Toyota has driven home with the hood pointing towards the sky several times with a \$10 load.
On the West side we have two gigantic pits that sell foundry and blasting sand. This stuff is washed, dried, graded to a single sieve and bagged before you even see it. Loading the Toyota to approximately the same angle cost between \$18 and \$25 depending on the grade.
That \$1.50 bag at the pit costs \$3 at Air Compressor Sales, 6 miles from the pit and \$5 in Atlanta, 90 miles from the pit.
Jim McGill wrote:
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You're also going to have to standardize how you settle it before you measure it.
Pour a can over-full of sand, scrape it level. Now gently tap the sides of the can round and round, watch the sand settle. How accurate do you need your volume measurement? Could you use water instead? It's lighter, cheaper, settles perfectly every time, and evaporates when you're done.
-- Carl West snipped-for-privacy@comcast.net