Does AL deteriorate?

[Richtee]

Or Perc for that matter? My supplies are several years old and not stored PERFECTLY.

 

My Vitamin F seems rather sluggish to ignite and diminished in power.

 

Odd...

[a_bab]

Perc is stable, it has no issues bar caking.

So the problem may be your Al especially if stored in humid places.

Edited December 29, 2021 by a_bab

[Richtee]

Perc is stable, it has no issues bar caking.

So the problem may be your Al especially if stored in humid places.

Yeah... the basement and not well sealed. Crap.

[Bourbon]

Can you dry AL the same as other stuff? Spread on a cookie sheet in the oven for a bit of a drying box?

[MadMat]

The surface of aluminum oxidizes almost immediately on contact with air. This creates a surface coating that protects the aluminum underneath, but like most things, this coating isn't perfect protection and after time the oxidation will continue on deeper down. Now with dark aluminum, it is composed of extremely small and thin flakes. I imagine after time, you will end up with a bag of aluminum oxide powder.

[Guest]

I wonder if whatever's inside an oxygen absorber has a greater affinity for oxygen than the aluminum.

[Richtee]

Can you dry AL the same as other stuff? Spread on a cookie sheet in the oven for a bit of a drying box?

I don’t think drying would matter. I bet it’s more an oxidation issue. Sigh. Well..it’s only a pound and a half or so. Prolly be fine for metal fuel stars and stuff.

 

Anyone interested for postage? US only, of course.

[Bourbon]

Damn.. That's a bummer... I haven't ran into this yet. I'm still using stuff 4-5 years old without issue. (Not stored great by any means but not bad) I hope sealed is good enough. I only have like 10 or 12 pounds left, and I bet I don't use 2 pounds a year. "I'm smaller then small scale hobbyist."

[mabuse00]

My humble opinion on this is that aluminum powder should last forever in storage.

 

The oxide layer should be stable. MgAl, Mg - different story.

 

Dark stuff is already oxidised, typical data sheets mention an "active metal content" of seventysomething percent. The rest should be mostly oxide. Eckard's data sheet for 5413 H states there is no degradation if stored correctly.

 

I wonder if moisture even matters, especially when no salts are around?

 

A few years ago I tested some bird bangers from the 1990s. They where absolutely fine. Since they are very small and no very strongly confined, I would assume that any stronger degradation would be easy to notice.

 

 

My Vitamin F seems rather sluggish to ignite and diminished in power.

Can you provide more details?

[Richtee]

My humble opinion on this is that aluminum powder should last forever in storage.

 

The oxide layer should be stable. MgAl, Mg - different story.

 

Dark stuff is already oxidised, typical data sheets mention an "active metal content" of seventysomething percent. The rest should be mostly oxide. Eckard's data sheet for 5413 H states there is no degradation if stored correctly.

 

I wonder if moisture even matters, especially when no salts are around?

 

A few years ago I tested some bird bangers from the 1990s. They where absolutely fine. Since they are very small and no very strongly confined, I would assume that any stronger degradation would be easy to notice.

 

Can you provide more details?

I don’t have an issue with a visco ignition, but I notice a lack of what I recall in “response”. And I some times put a couple milligrams on a sheet of paper and touch a cig to it Just a test.. Last time..it just did nothing for 5 seconds. Not like instantaneous before.

Edited January 1, 2022 by Richtee

[Bourbon]

I'd try drying the crap outta everything just out of curiosity.. That's me though. It would eat at me if I didn't.

[Richtee]

I'd try drying the crap outta everything just out of curiosity.. That's me though. It would eat at me if I didn't.

Yer right. On it. “Honey.. no waffles in the toaster oven this AM..”

[mabuse00]

 

drying the crap outta everything

That's the only thing I can imagine...

 

Be careful heating the Al. It often contains a very small amount of wax, I don't know what happens when you melt that. Like clumping or so...

 

 

I don’t have an issue with a visco ignition, but I notice a lack of what I recall in “response”. And I some times put a couple milligrams on a sheet of paper and touch a cig to it Just a test.. Last time..it just did nothing for 5 seconds. Not like instantaneous before.

That does not sound like a power problem to me. More like a "felt problem" that really is not substantial. Try some small inserts or crackers, I bet it's OK.

[Crazy Swede]

Most dark or pyro aluminium powder does age, the finer the faster. IN an early stage the problem is that it clumps together, so that more effort is needed in distributing it evenly with the oxidiser. If really detoriated too much aluminium metal is lost and it should be discarded.

 

Bright aluminium with stearate coating as well as atomized qualities tend to store better.

[WSM]

A real clue about ANY metallic material is, does it appear in nature in it's native form? That is, do you find metallic aluminum in nature (like gold is usually found as metallic gold, not salts of gold; where silver is usually found as salts of silver and needs to be refined to "win" it from the ore)?

 

The clear answer is no, aluminum is found in nature as bauxite and a lot of energy is required to produce metallic aluminum.

 

The major key is to be sure aluminum, especially powders, are "stored properly".

 

If mixtures containing it work great today, but later seems sluggish, the problem is usually either chemical or physical.

 

If it's chemical, that's a one way street. Nature almost always goes from order to chaos, meaning from a well organized material to the form usually found in nature. Take iron, for example: if it's not protected by some means and then exposed to the elements, it slowly goes from an iron item to rust. Eventually it's only rust.

 

If it's physical, there are myriad ways an item can degrade in performance:

• a loose powder mixture can clump up, slowing down the earlier performance
• a loose powder can separate into various layers, a heavy component separating from lighter, fluffier components, for example
• a pressed item can be affected by environmental conditions (nitrate leaching out of a comet in humid conditions, for example)
• parts of a bound composition reacting with other incompatible parts, over time (unprotected magnesium and potassium nitrate bound with NC - Inert within a year, but very reactive when "fresh"). This is actually more chemical than physical

We need to think outside the box sometimes, to gain an understanding of all the many variables and possibilities of why our items don't perform the way we expect they will (or did once).

 

Consider:

• environment and all the variables involved
• storage conditions
• time
• temperature
• humidity
• degree of incorporation
• particle size of individual and mixed components
• whether sealed or exposed to atmosphere (some things need to breathe to release detrimental decomposition products)
• All other variables you can think of...

Networking can help with analyzing why some problem occurred and possible solutions; which you've done by posting your problem here. Not every response will be the answer, but considering each one and how it may apply may well lead you to discover what has happened or was done to cause the situation you're dealing with.

 

Good luck! Oh, and share the solution if you feel you've figured it out. We all benefit that way.

 

WSM

Edited January 3, 2022 by WSM

[Bourbon]

Been a couple days.. Hope your toaster didn't get jiggy wit it.....

[Richtee]

Been a couple days.. Hope your toaster didn't get jiggy wit it.....

Actually have not got to it yet.... Lots of folks arouind for the holidays. Din’t think take\ing over the toaster oven for pyro experimentation was a wise move

[Bourbon]

Actually have not got to it yet.... Lots of folks arouind for the holidays. Din’t think take\ing over the toaster oven for pyro experimentation was a wise move

Right on. Good to know..

[Richtee]

So I dried out 3 grams. 200°F for 15 mins. Also broke out 3 grams same batch but not opened. Double zippie’d from the supplier.

 

I mixed up 7-3 2 batches. The dried one... seemed marginally better. The unopened one was ..well..hellfire. I’d have to say..take care of your AL.

 

The opened stuff will still “git R Done” but there is a noticeable reduction in it’s performance.

 

I think WSM kinda spelled out why too. Probably why ya never hear of a AU/oxidizer mix for the rich. It won’t work

[Bourbon]

I agree, WSM covered all the bases there. Made it a pleasure to read too.

 

Glad you shared your experience with your experiment. Glad you can still use it for other things, or the same confined for that matter... I hate wasted supplies!

[mabuse00]

I still believe (or maybe I want to) that Al's oxide layer is stable under normal conditions...

 

Another thought:

there may be some variants of Al that rely on being fresh and not oxidised when delivered, rather than small size. These will work when rather fresh but suffer when oxidation of the surface is finished.

[Richtee]

I still believe (or maybe I want to) that Al's oxide layer is stable under normal conditions...

 

Another thought:

there may be some variants of Al that rely on being fresh and not oxidised when delivered, rather than small size. These will work when rather fresh but suffer when oxidation of the surface is finished.

I think I abused the stuff alot. Left open to atmosphere thru the humid summers here...moved about..in general poor material handling. Don’t get me wrong..it’s NOT useless..but it ain’t got that swing... like the sealed stuff.

[itwasntme]

So I dried out 3 grams. 200°F for 15 mins. Also broke out 3 grams same batch but not opened. Double zippie’d from the supplier.

 

I mixed up 7-3 2 batches. The dried one... seemed marginally better. The unopened one was ..well..hellfire. I’d have to say..take care of your AL.

 

The opened stuff will still “git R Done” but there is a noticeable reduction in it’s performance.

 

I think WSM kinda spelled out why too. Probably why ya never hear of a AU/oxidizer mix for the rich. It won’t work

 

I had the same exact issue.

 

Personally I work in rather small batches, so what I do is take a small sealable plastic cup, put in a small amount of chem and work from that vs from the original packaging. This means that my chem sits out on the table rather poorly sealed, but in approx 20 gram amounts.

 

Originally sealed aluminum and magnesium powders worked like they always did, while the stuff in the plastic cup for about a year, worked, but not nearly as well as the original.

[Richtee]

Further analysis - it IS the perc gone sour. I dried it as well, not much change. 70-30 with 3 different fuels gives me “slow flash” at best. No ignition on a double voice even, and the “timing Visco” was burned thru the core into the charge.

Same metals with a fresh bag of perc... blammo. Odd... What happens to perc? Must be moisture or oxygen related.

Edited June 24, 2022 by Richtee

[Richtee]

If anyone in the US has a cell project and could possibly reclaim it, I have about 4 pounds I’ll send for shipping costs. About $10.