6 replies to this topic

[Pyro Harold]

I have a question I am hoping someone might be able to answer, as most of us know Magnesium must be coated when combined with certain chemicals to prevent a reaction, now with magnalium which consists of both magnesium and aluminium why is there no need for it to be coated? Or am I jumping the barrel here, is it coated? Or does it not need to be coated because it is used with chemicals which do not form a reaction, or my third suspicion is that a neutralizing chemical is added to formulas which contain it?

[megabusa]

Magnalium is just an alloy of Mg & Al usually 50:50, although other ratios are prefered by some.

It is not normally coated (certainly in the comps I have used) & it does not have anything added to the alloy when made.

I always assumed that the aluminium oxide layer (that naturally forms quickly around Al) protected the alloy, so coating was not necessary as it is with pure Mg.

Thats my take on it.

It would be interesting for someone like Mumbles to jump in here.


Phil.

[Pyro Harold]

Magnalium is just an alloy of Mg & Al usually 50:50, although other ratios are prefered by some.

It is not normally coated (certainly in the comps I have used) & it does not have anything added to the alloy when made.

I always assumed that the aluminium oxide layer (that naturally forms quickly around Al) protected the alloy, so coating was not necessary as it is with pure Mg.

Thats my take on it.

It would be interesting for someone like Mumbles to jump in here.


Phil.

Thank you for the fast reply Phil.
So Magnalium isn't just simply magnesium & aluminium powders combined/miced? Are the two metals smelted together and then ground down to powder form?
My main concern was how stable the magnalium would be in relation to combining it with certain chemicals?

[cooperman435]

My belief is the same as Mega, the aluminium acts as a protective layer and prevents the reactions normally associated with Mg alone

[Creepin_pyro]

While most of the time it can be used uncoated, and many have had no problems with it, it's worth noting that people have observed reactions with AP strobes and some other formulas.

So depending on the comp it might be worth doing a small test with uncoated MgAl before making a larger batch. If using Parlon and binding with acetone, the coating should be enough to stop any reaction.

Making the alloy is well documented, there are a few safety issues with making it and reducing it to powder so make sure you're aware of the issues before attempting anything.

http://www.amateurpy...ching-diy-mgal/

[digger]

While most of the time it can be used uncoated, and many have had no problems with it, it's worth noting that people have observed reactions with AP strobes and some other formulas.

So depending on the comp it might be worth doing a small test with uncoated MgAl before making a larger batch. If using Parlon and binding with acetone, the coating should be enough to stop any reaction.

Making the alloy is well documented, there are a few safety issues with making it and reducing it to powder so make sure you're aware of the issues before attempting anything.

http://www.amateurpy...ching-diy-mgal/

I agree. I also find that there can be reactions when using water binding systems in compositions that contain nitrates.

[Pyro Harold]

Thank you veyr much for the replies, I feel more confident using magnalium in mixtures.