7 replies to this topic

[Plays with Fire]

Okay, I've just spent a long while searching the internet in general, as well as in this forum, and still cannot find the information I'm looking for; not quite sure this is the correct forum but Chemistry and Formulas both seemed even more off - Anyway...

I currently have no acess to mesh screens, and would like to know about what mesh my compositions are. I have a simple spaghetti strainer, but still don't know what mesh it is either. So, it would be very useful if someone could tell me the various meshes of the following compounds, for comparison:
1. Table Sugar
2. Baking Flour

Also, if you can think of anything else an american would have around his house (mounds of duct tape and thick plastic wrap don't count !) then I'd like to know their meshes too.

Ignorantly yours,
Plays with Fire

[Frozentech]

Okay, I've just spent a long while searching the internet in general, as well as in this forum, and still cannot find the information I'm looking for; not quite sure this is the correct forum but Chemistry and Formulas both seemed even more off - Anyway...

I currently have no acess to mesh screens, and would like to know about what mesh my compositions are. I have a simple spaghetti strainer, but still don't know what mesh it is either. So, it would be very useful if someone could tell me the various meshes of the following compounds, for comparison:
1. Table Sugar
2. Baking Flour

Also, if you can think of anything else an american would have around his house (mounds of duct tape and thick plastic wrap don't count !) then I'd like to know their meshes too.

Ignorantly yours,
Plays with Fire

Well... this is a wild ass guess, so take it with a grain of salt ( about 20 mesh ) I've never tried screening kitchen ingredients for mesh size.

Table sugar I think is about 30 mesh
white flour probably around 150 mesh ?

You don't absolutely need a particular mesh to make compositions. Make sure the chemicals individually are as fine as possible, using a coffee grinder perhaps. Use a regular kitchen strainer ( not a colander, a wire strainer ) to screen chemicals together ( unless it's a sensitive mix like flash which needs to be diapered to mix )

Personally I can't tell by eye, most meshes beyond 100 look like talcum powder to me, I can tell 100 from -325 by feel though. 325 and smaller feels 'smooth'.

[edit] after posting this I did a search on 'particle size of sugar, etc' and came up with a little bit of info:

Powdered sugar has an average particle size of 61 microns, so just a little finer than 230 mesh.
Standard granulated sugar is 450-600 u, so 35 mesh would be middle range ( I was close )
By British law, baking flour is nominally 63 micron particle, so right at 230 mesh.

Edited by Frozentech, 20 February 2006 - 06:19 AM.

[al93535]

Sorry post removed

Edited by al93535, 09 August 2006 - 06:30 PM.

[Andrew]

(1200) ...................... 0.0005 .............. 12 ......... Red Blood Cell

(2400) ................. 0.0002 ............. 6

(4800) ............. 0.0001 ......... 2 ............ Cigarette smoke



* The mesh numbers in parentheses are too small to exist as actual screen sizes; they are estimated and included just for reference.

Our mesh supplier can make upto 2400#, in a dutch weave mind. 800# is the finest you can get in a twill weave (twill is pretty much a plain weave), about 400#/500# for a plain weave.

The biggest thing with mesh sizes is that the LPLI measurement does not directly describe the aperture size; you have to take account of the wire diameter and weave. For example, in theory a dutch weave has 0% open area, but it does have apertures; very small ones!

Edited by Andrew, 20 February 2006 - 08:15 PM.

[Plays with Fire]

Thank you all very much; this is very helpful !

Recently I opened up an Etch-a-Sketch, and inside was some beads and *very* fine Al powder. It was so fine that it acted more like a gel/liquid than a powder. Does anyone have any idea what mesh a chemical has to be in order to act this way? Do other chemicals do this as well, at a high enough mesh?

Curiously yours,
Plays with Fire

[Frozentech]

Thank you all very much; this is very helpful !

Recently I opened up an Etch-a-Sketch, and inside was some beads and *very* fine Al powder. It was so fine that it acted more like a gel/liquid than a powder. Does anyone have any idea what mesh a chemical has to be in order to act this way? Do other chemicals do this as well, at a high enough mesh?

Curiously yours,
Plays with Fire

The Al in an Etch-A-Sketch looks and acts a lot like 325 mesh bright flake, with stearin coating.

[Plays with Fire]

The Al in an Etch-A-Sketch looks and acts a lot like 325 mesh bright flake, with stearin coating.

Is it the coating that gives it these hard-to-work-with, gel-like properties? I can't believe that one could work with such an impractical substance; it sticks to, and coats everything. I can't contain it, or somehow measure it. I tried to scoop it with a peice of paper, but it just formed a layer on top of the paper, that didn't come off !

Frustratedly yours,
Plays with Fire

P.S. While we're on the topic of Stearin Coating, is this similar to linseed oil, and is a a liquid that's just mixed with the powder thoroughly?

[Frozentech]

Is it the coating that gives it these hard-to-work-with, gel-like properties? I can't believe that one could work with such an impractical substance; it sticks to, and coats everything. I can't contain it, or somehow measure it. I tried to scoop it with a peice of paper, but it just formed a layer on top of the paper, that didn't come off !

Frustratedly yours,
Plays with Fire

P.S. While we're on the topic of Stearin Coating, is this similar to linseed oil, and is a a liquid that's just mixed with the powder thoroughly?

I cracked open an Etch-A-Sketch long ago, and all it is good for is making a mess. From what I've been able to find searching online, there is under 3 grams of Al powder in there, the bulk of it is styrene beads.

It's not the coating that makes it hard to work with, it's the tiny quantity. Fine Aluminum will coat everything it touches, and bright flake 325 mesh makes all your tools look like they were painted silver. The stearine / stearic acid is a soaplike waxy chemical that helps prevent oxidation of the powder. I do not know how it is applied in Al powders, but it can be bought separately as a fine powder.