lbs. glass = sq.inch

[lynn]

Does anyone have a formula for how many oz. of glass = how many sq. " fused ( approx. 1/4" thick) ?

For instance 28 oz. = ?

I have tried the archives, but may be using the wrong search.

Thanks from the mathematically challenged! :shock:

[lynn]

and the html challenged as well......

[charlie]

1.6 lbs/sqft

[Tony Smith]

Glass weighs 155 lbs/ft³ whic meand that a piece of glass 12" x 12" x 1" thick weighs 155/12=12.91 lbs.

1/4" thick would be 1/4 of 12.91 or 3.23 lbs/ft².

Tony

[Brad Walker]

Does anyone have a formula for how many oz. of glass = how many sq. " fused ( approx. 1/4" thick) ?

For instance 28 oz. = ?

Sounds like a pot melt question.

1.6 pounds/square foot is the rule of thumb for 1/8" thick glass.

For 1/4 inch thick (roughly what melted glass would spread to), you need to double the rule of thumb to get 3.2 pounds/square foot.

That's 3.2 * 16 = 51.2 ounces per 144 square inches.

So 28 ounces would be 28/51.2 times 144 = 78.75 square inches.

That's a circle of roughly 10 inch diameter (I'll spare you the math!).

BUT if you're doing this all for a pot melt, the actual circle will be smaller. This is due to two factors:

1. Some glass will stick to the pot.
2. The glass will actually be slightly thicker than 1/4"

[lynn]

Thank you all!
actually it is not a pot melt, but a bottle melt.
I want to crack up and melt bottles using as glass ...not looking like bottles.
I am assuming that different brands, may use dif. glass and will not be able to be used together due to coe.

We are moving and will be building. I am looking at making "tiles" that will be used in a room divider ( of sorts....complicated) made out of green bottle glass . I love the color and gee, drink plenty of wine.

[Bert Weiss]

Thank you all!
actually it is not a pot melt, but a bottle melt.
I want to crack up and melt bottles using as glass ...not looking like bottles.
I am assuming that different brands, may use dif. glass and will not be able to be used together due to coe.

We are moving and will be building. I am looking at making "tiles" that will be used in a room divider ( of sorts....complicated) made out of green bottle glass . I love the color and gee, drink plenty of wine.

Lynn

Bottle glass is formulated to stiffen soon after it is formed. This is the opposite of how one would design a "casting" glass. The good news is that bottle glass is often recycled so you might have luck fusing the frits. That is as long as a tack fuse works for your look.

[Judy Schnabel]

Lynn,

Be careful mixing different bottles -- even the same brands.

Some brand bottles are manufacturered by different companies so the COE is different. I'm afraid you might have lots of cracks.

Judy

[Dani]

You don't like the slumped bottle idea for the wall? 49 bottles of beer on the wall, 49 bottles of beer...... LOL. I rather thought the look would be intriguing and still might try it in the studio.... there's a curious visual effect when they're all lined up with every other row upside down bottles. Might be easier to apply them if you cut the bottoms off before slumping though. Can you tell I've thought about this a while?

[AVLucky]

You don't like the slumped bottle idea for the wall? 49 bottles of beer on the wall, 49 bottles of beer...... LOL. I rather thought the look would be intriguing and still might try it in the studio.... there's a curious visual effect when they're all lined up with every other row upside down bottles.

They did that on an episode of The Simpsons. I would love to see it for real!

[charlie holden]

Does anyone have a formula for how many oz. of glass = how many sq. " fused ( approx. 1/4" thick) ?

For instance 28 oz. = ?

I have tried the archives, but may be using the wrong search.

Thanks from the mathematically challenged! :shock:

Want a lesson in specific gravity? Here's the formula: volume times specific gravity equals weight. The hitch is you have to do it in metric. (Buy a tape measure with a metric scale on it and a scale that weighs in grams and never worry again about 16 oz's in a lb or 12 inches in a foot or 4 quarts in a gallon.)

A material's specific gravity tells you how much more or less a given volume of it will weigh than that same volume of water. Water has a specific gravity of one. That means that one liter of water weighs one kilogram and one cubic centimeter of water weighs one gram.

Soda lime glass has a specific gravity of 2.55. That means that one liter of soda lime glass weighs 2.55 kilograms. If you can figure out the volume in liters of a mold or tile, you multiply that by 2.55 and you get the weight of glass you will need in kilograms.

Remember that 10 millimeters = 1 centimeter, 1000 cubic centimeters = 1 liter, and 1000 grams = 1 kilogram.

So let's say your tile is 6mm thick x 152mm x 152 mm (1/4" x 6" x6").

1. Convert that to centimeters (cm) and multiply: .6cm x 15.2cm x 15.2 = 138.624 cubic centimeters (cc) per tile.

2. Divide that by 1000 to get liters = .138624 liters of glass per tile.

3. Multiply by the specific gravity of the glass, 2.55 = .3535 kilograms of glass per tile.

4. Multiply again by 1000 to get grams = 353.5 grams per tile, (since you would probably weigh out this much glass on a gram scale).

Note, if you know you are going to be measuring small volumes and weights, (staying with cc's and grams), you can just skip steps 2 and 4 as they cancel each other out.

If you wanted to use Gaffer lead crystal instead of soda lime glass you use its specific gravity of 3.6 instead of 2.55 (it's much heavier) to get 499 grams per tile.

ch

[Lynne Chappell]

Wow, I'm going to have to print that out. I'm OK with math, but that boggles the mind.

I think the 1.62 lbs/sqft for 1/8" thick glass will do for me. Actually, if you round it off to 1.5 you can do it all in your head. Double thick= 3 lbs, 4 layers = 6 lbs, etc.

I have noticed when weighing glass rods that some colors seem to weigh more than others. Something to do with heavy metals I guess.

[Jackie Beckman]

Does anyone have a formula for how many oz. of glass = how many sq. " fused ( approx. 1/4" thick) ?

For instance 28 oz. = ?

I have tried the archives, but may be using the wrong search.

Thanks from the mathematically challenged!

Want a lesson in specific gravity? Here's the formula: volume times specific gravity equals weight. The hitch is you have to do it in metric. (Buy a tape measure with a metric scale on it and a scale that weighs in grams and never worry again about 16 oz's in a lb or 12 inches in a foot or 4 quarts in a gallon.)

A material's specific gravity tells you how much more or less a given volume of it will weigh than that same volume of water. Water has a specific gravity of one. That means that one liter of water weighs one kilogram and one cubic centimeter of water weighs one gram.

Soda lime glass has a specific gravity of 2.55. That means that one liter of soda lime glass weighs 2.55 kilograms. If you can figure out the volume in liters of a mold or tile, you multiply that by 2.55 and you get the weight of glass you will need in kilograms.

Remember that 10 millimeters = 1 centimeter, 1000 cubic centimeters = 1 liter, and 1000 grams = 1 kilogram.

So let's say your tile is 6mm thick x 152mm x 152 mm (1/4" x 6" x6").

1. Convert that to centimeters (cm) and multiply: .6cm x 15.2cm x 15.2 = 138.624 cubic centimeters (cc) per tile.

2. Divide that by 1000 to get liters = .138624 liters of glass per tile.

3. Multiply by the specific gravity of the glass, 2.55 = .3535 kilograms of glass per tile.

4. Multiply again by 1000 to get grams = 353.5 grams per tile, (since you would probably weigh out this much glass on a gram scale).

Note, if you know you are going to be measuring small volumes and weights, (staying with cc's and grams), you can just skip steps 2 and 4 as they cancel each other out.

If you wanted to use Gaffer lead crystal instead of soda lime glass you use its specific gravity of 3.6 instead of 2.55 (it's much heavier) to get 499 grams per tile.

ch

[-X =;

[charlie holden]

:shock: 8-[ :-s #-o [-X =;

OH COM'ON!? I understand that this is a slightly advanced caster's technique. But things are dead over there right now and I think it might be useful over here for one or two fusers.

What could be simpler -- volume times specific gravity equals weight. That's it. Soda lime is 2.55 kilos per liter and 2.55 grams per cc. Any manufacturer can give you the specific gravity of their glass.

The rest is just getting your units right. If you have a tape measure that has a metric scale you don't even have to convert from inches to centimeters.

If you use Brad's formula you still have to convert from decimal fractions of a pound to pounds and ounces if you don't have a digital scale. Or you may have to convert inches to decimal fractions of a foot. (What if you want your tiles to be 5 7/8" square so you can leave an 1/8" grout line around each one, yet stay on a 6" square layout?) How many cups in a 1/8 inch thick square foot? How many tablespoons?

Caster's use formulas like this because it is easy to figure out the volume of a sculptural piece. I measure how much water I pour into a mould to fill it up. That measurement is in ounces or liters. It's not practical for me to define a unit of volume as a 1/8" thick square foot.

ch

[Bert Weiss]

Charlie

I found it useful enough to copy and store on my computer. Thanks!

I don't think well in metric, but I see that the correlations between a volume of water and weight of glass are very useful. I never really understood specific gravity before. That is a pretty simple concept.

[Jackie Beckman]

[-X =;

OH COM'ON!? I understand that this is a slightly advanced caster's technique. But things are dead over there right now and I think it might be useful over here for one or two fusers.

What could be simpler -- volume times specific gravity equals weight. That's it. Soda lime is 2.55 kilos per liter and 2.55 grams per cc. Any manufacturer can give you the specific gravity of their glass.

The rest is just getting your units right. If you have a tape measure that has a metric scale you don't even have to convert from inches to centimeters.

If you use Brad's formula you still have to convert from decimal fractions of a pound to pounds and ounces if you don't have a digital scale. Or you may have to convert inches to decimal fractions of a foot. (What if you want your tiles to be 5 7/8" square so you can leave an 1/8" grout line around each one, yet stay on a 6" square layout?) How many cups in a 1/8 inch thick square foot? How many tablespoons?

Caster's use formulas like this because it is easy to figure out the volume of a sculptural piece. I measure how much water I pour into a mould to fill it up. That measurement is in ounces or liters. It's not practical for me to define a unit of volume as a 1/8" thick square foot.

ch

Oh Charlie - you misunderstood my little guys! I think it was wonderful of you to share all that. I only wish I could get through it without my pupils starting to spin and smoke spilling from my ears. It's not you, it's me, really. (I've always loved saying that)

Jackie

[Doug Randall]

Charlie

I found it useful enough to copy and store on my computer. Thanks!

I don't think well in metric, but I see that the correlations between a volume of water and weight of glass are very useful. I never really understood specific gravity before. That is a pretty simple concept.

Exactly as Bert said....That formula is probably the simplest way to fill any void with the exact amount of glass. Thanks for posting it Charlie!

[charlie holden]

Oh Charlie - you misunderstood my little guys! I think it was wonderful of you to share all that. I only wish I could get through it without my pupils starting to spin and smoke spilling from my ears. It's not you, it's me, really. (I've always loved saying that)

Jackie

Don't worry Jackie, I didn't take it personally. I would have used a couple of them myself if I'd known how.

ch