Mg and MgAl coating

[Deafaid]

I need a good description on how to coat magnesium and magnalium. I DON'T want to use potassium dichromate! don't have the guts.

I've read that paraffin oil and linseed oil works? Hope i can get some help.

[Swede]

Some stuff I posted on Passfire:

 

After reading of these various methods to coat Mg, the use of Parlon or some other polymer that is soluble in acetone and similar, is quite intriguing. Vastly less toxic than the dichromate, much less messy than linseed, and having the benefit of extremely rapid drying. Has anyone tried it yet? I'm willing to give it a shot with a small sample.

 

Before Mike and Tom replied, for curiosity's sake, I attempted a parlon/MEK coating on a 1/2 gram sample. Because I used fairly coarse Mg, maybe 40 mesh, I didn't notice any horrible handling issues, but again, 1/2 gram is not a lot. A quick test with HCl showed significant resistance, but not absolute. The untreated Mg evolved hydrogen vigorously. The parlon coated Mg clumped, and the clump captured minute hydrogen bubbles, which floated the clump upwards like a raft. I cannot even begin to guess the difference in evolved hydrogen, but visually, at least, it was fairly impressive. I cannot draw any valid conclusions as to the suitability of parlon or similar... I agree that being a mechanical coating is a significant drawback compared to dichromate. But for a 20 minute experiment, it was interesting, and possibly worthy of further investigation.

 

http://www.5bears.com/firew/mgcoat93.jpg

 

It might be worth further experimentation using Parlon or similar rubbery polymer coating for Mg. From the basic acid attack tests I conducted, the Parlon actually was superior to dichromate. I think I posted some of the research here on APC as well.

[dagabu]

Swede,

 

I remember that and I used Parlon to coat my Mg and it worked fine while drying, no smell or growing stars. I haven't shot the stars yet so I don't know how they perform but they shot well out of the gun and on the ground.

 

D

[firetech]

It is debated, but MgAl doesn't need to be coated according to some, it does to others. You should be alright depending on what your comp is.

[dagabu]

It is debated, but MgAl doesn't need to be coated according to some, it does to others. You should be alright depending on what your comp is.

 

LOL! Grab your camcorder and make some stars using uncoated 300 mesh Mg and a water based binder. It will bring you to Jesus!

 

D

[firetech]

I said nothing about Mg. I said MgAl, which is far less reactive than Mg alone. It also becomes much less reactive if you are using a high Al content MgAl. I also said "depending on your comp" because of the way it would be bound (alcohol/water). Do you really have to pick apart everything I say? Edited December 3, 2009 by firetech

[dagabu]

I said nothing about Mg. I said MgAl, which is far less reactive than Mg alone. It also becomes much less reactive if you are using a high Al content MgAl. I also said "depending on your comp" because of the way it would be bound (alcohol/water). Do you really have to pick apart everything I say?

 

Meh, it's a free forum, we are the only ones responding, its a risk, missed the MgAl, thought it was straight Mg.

 

D

[Ericz]

I said nothing about Mg. I said MgAl, which is far less reactive than Mg alone. It also becomes much less reactive if you are using a high Al content MgAl. I also said "depending on your comp" because of the way it would be bound (alcohol/water). Do you really have to pick apart everything I say

 

 

Dagabu is right , if the parlon way works . Why not ? Why alwase think lazy and take a risc just coat all your mg even when u use nc lak stars who cares. Savety is nice right ?

Dont think its a attack but you have to take as many riscs away when u do this hobby righT?

grtz

[dagabu]

I hope the laziness shown in the composition of this post is not a reflection of how careful you are w/fireworks. Possibly a munged translation?

 

The why's and wherefore's are well known in re treating metals. Parlon would seem to be a viable solution (NPI) to treating some metals, and the research that was done by Swede is VERY interesting (and thanks for sharing it w/the forum, BTW!). Enough so, that I am going to try the same technique myself just to see.

 

But if there is no parlon, or if the added expense and time/complications can be avoided for a more traditional, cheaper and/or less complicated method, why not that?

 

Personally, I do not make any stars or comps in general that require the magnalium I use, to be treated. I believe the mesh size has a lot to do w/this, finer = more reactive all the way around.

 

After the soiree last night I got to thinking (wife sent me outside to thin the smoke) and hobbled out to the shop for a look see and I found my brite Al flake I used is car paint. The stuff has to be treated with Boric Acid or it boils on contact with water. Making sparklers is a pain with the stuff so I tried some parlon (1%) and alcohol for coating Al.

 

It was only 10 grams so I got it dried in about 1/2 hour and made a tiny batch of D1. Low and behold, no ammonia (thats what I call it) smell, no boiling, no heat. It seems to work as well as Boric Acid so far. I will let them dry till the weekend and make a ball shell for testing and let you know if the parlon did anything to the color.

 

D

[oldguy]

I have some Mg, Mg/Al & Al in differing mesh sized I want to coat to minimize the chance of them reacting with anything else in various comps.

The toxicity involved with Potassium dichromate makes me not want to use it.

In reading this thread, it seems a dilute acetone parlon solution would suffice.

Is that the general consensus?

I ask because some of the these could end up being stored for a considerable time before use.

I would hate to have any self combust, for obvious reasons.

 

Edited January 29, 2011 by oldguy

[Bonny]

I don't use any Mg myself, but I've never coated my MgAl. I've got Veline and Ruby Red stars (all contain MgAl) that are over 2 years old...I made some bigger batches than needed. I was just starting to roll stars and added FAR too many cores

 

I think reducing the batch size to what would be consumed in a few months or a season is better than longterm storage.

[dagabu]

Man, I have used a good 10# of MgAl since that post and have NEVER had a single problem with MgAl being uncoated. If it was -350 mesh I would coat it but I dont bother with anything bigger. Who knows, I may be playing Russian Roulette but so far so good.

[NightHawkInLight]

Who knows, I may be playing Russian Roulette but so far so good.

Doubtful. If it doesn't react in a comp while binding and drying it would need to be stored under some pretty horrendous conditions to find itself in a state more prone to react than it was when wet. That's my thought anyway.

[pyrogeorge]

i plan to coat my mgnal with linseed oil and i will use 5%..Is it enough to coat?

maybe less or more?any suggestions?

 

Thanks

[dagabu]

i plan to coat my mgnal with linseed oil and i will use 5%..Is it enough to coat?

maybe less or more?any suggestions?

 

Thanks

 

I just made another batch of cut stars with -350 mesh MgAl this past weekend and there was no issue with thew water bound comp. I also made several pounds of AP based red falling leaves last year with MgAl and did not treat it in any way with no issues with degradation even a year later when I used the last of the leaves at PGI this year.

 

-dag

[pyrogeorge]

i plan to coat my mgnal with linseed oil and i will use 5%..Is it enough to coat?

maybe less or more?any suggestions?

 

Thanks

Also,can i use the same method with magnesium?

[Bonny]

Also,can i use the same method with magnesium?

 

Linseed oil? For sure. I think Shimizu wrote about different coatings for Mg, with dichromate being better though. It might depend on what you plan on mixing it with.

[Mumbles]

Linseed oil is actually a better coating for pretty much everything, except that it doesn't stand up to ammonium perchlorate what so ever. I've only coated with dichromate, but I've seen values between 2 and 5% for linseed oil.

[pyrogeorge]

thanks guys!

I don't plan to use it with ammonium perchlorate..

i coat my mgal with 5% to be sure that will be full coating and i will do the same with the magnesium.

[50AE]

I've never worked with Mg. The only case with MgAl that scared me, was wetting a 500g metallic white star mix, having Ba(NO3)2 and MgAl. The magnalium was very fine, about 300 mesh average. I wanted the mix to be fast. With the addition of water, the mix almost instantly heated up in my hands and it smelled ammonia, so I quickly added some very cold water. The heat went away and the star comp was then cut without issues.

[pyrogeorge]

Did you use coated MgAl or not?

[50AE]

It was uncoated, it wouldn't heat up otherwise.

[pyrogeorge]

ok because i start to scare