51 replies to this topic

[Bonny]

Should I go for this fellow's aluminum powder?

http://search.ebay.c..._full_orchestra

I received my 1lb of Al from this guy last week. The ad says 1600mesh aluminum "very fine dust". I do question the particle size as that is extremely fine. The powder is light grey, but my main question is if this is granular/atomized or flake Al. Would it perform well in flash (70/30)? Or would it be better suited to other applications? I have some dark Al, but it was very difficult to acquire so I would like to use this other Al whenever possible.

[MDH]

It seems to work perfectly well with nitrate flash. It passed through a piece of cheap tissue so I won't doubt how fine it is.

[Bonny]

It seems to work perfectly well with nitrate flash. It passed through a piece of cheap tissue so I won't doubt how fine it is.

Awesome! I haven't really made many nitrate flashes, but it should probably work OK then in 70/30 perc/Al flash. Any idea though if it is granular or flake?

[MDH]

It is definitely granular. I have milled some of it carefully into flake and it's incredibly shiny when it is. When in flake some of it sticks together so you have to add an anti caking agent and sift it through (Cab-o-sil if you have any. I actually use fine balsa charcoal which interestingly enough keeps it very fluffy).

[FrankRizzo]

It is definitely granular. I have milled some of it carefully into flake and it's incredibly shiny when it is. When in flake some of it sticks together so you have to add an anti caking agent and sift it through (Cab-o-sil if you have any. I actually use fine balsa charcoal which interestingly enough keeps it very fluffy).

You fellas should take a look at the following two reports. The gist is that optimum results are achieved with 3 wt.% stearic acid or 5 wt.% oleic acid and a 100% weight ratio of mineral spirits to aluminum, milled for 60hrs at optimum RPM for the mill jar diameter (65% of critical RPM).

Critical RPM = 265.45/sqrt(Jar I.D. - Media O.D.)

wet aluminum powder fabrication.pdf
manufacturing of flake aluminum powder.pdf

[Bonny]

You fellas should take a look at the following two reports. The gist is that optimum results are achieved with 3 wt.% stearic acid or 5 wt.% oleic acid and a 100% weight ratio of mineral spirits to aluminum, milled for 60hrs at optimum RPM for the mill jar diameter (65% of critical RPM).

Critical RPM = 265.45/sqrt(Jar I.D. - Media O.D.)

wet aluminum powder fabrication.pdf
manufacturing of flake aluminum powder.pdf

Very good info, however I think it would be too much hassle to bother with. For now I think I'll just continue buying my Al powder.

[FrankRizzo]

Very good info, however I think it would be too much hassle to bother with. For now I think I'll just continue buying my Al powder.

As will I, along with all the other oxidizers, coloring agents, etc. that I use on a routine basis. My time is worth too much to put forth all the effort to make the basic necessities from scratch. The information may become relevant if the regulatory climate continues on it's current path. I think the safety fakers will have a tough time regulating cheap aluminum food wrap, paint thinner, and candle making supplies...

Edited by FrankRizzo, 23 November 2007 - 07:24 AM.