Sciencemadness Discussion Board

Magnesium ribbon for thermite

crazedguy - 29-1-2011 at 13:02

Thermite kits come with a one inch Mg ribbon how long would that last or could a Visco fuse ignite Mg?

The WiZard is In - 29-1-2011 at 14:40

Quote: Originally posted by crazedguy  
Thermite kits come with a one inch Mg ribbon how long would that last or could a Visco fuse ignite Mg?

Visco? NO. Visco uses fuse powder - a slow burning
black powder comp. Well -- except in KY some years ago when
someone made up a batch of visco using fast burning power. The
country side was littered with fingers removed by instantly exploding M80's.

As I said to my previous neighbour years ago when he asked me
to put flame to an impressive size ground bomb he had purchased.
I would only lite a device like that is if I had made it.

Any day you have an excuse to burn some Mg ribbon is
a good day.

Using the thousand-one, thousand-two method of timing. 1
inch of Mg ribbon burns 5-seconds, remember there will be
some buried in the thermite so deduct a second - second and a half
or so.

I have seen a common fireworks sparker used to ignite Cadweld
(copper oxide thermite).

* Good day?!

What do you do with
365 used condoms?

Melt them down make
a tire and call it a Goodyear.

crazedguy - 30-1-2011 at 14:05

What would it take to right said magnesium a propane torch right?

The WiZard is In - 30-1-2011 at 14:10

Quote: Originally posted by crazedguy  
What would it take to right said magnesium a propane torch right?

Correct. I tried two SAW matches last night w/o effect.
Even la propane torch took longer then I remembered.

crazedguy - 30-1-2011 at 19:50

Thanks for the info definitely helps, the way i set my flash bombs up is a medicine bottle with the fuse through the top, could I do the same with this thermite in the medicine then magnesium ribbon through the top sealed with hot glue so nothing goes in or out?

So the question is will the magnesium ribbon burn with something around it into the themite and ignite the thermite?

condennnsa - 30-1-2011 at 22:13

Actually, with some effort , magnesium can be ignited with matches, your enemy, in case of ribbon is its high conductivity, you only have to bring it up to its melting point of 650C to ignite.

Magnesium ribbon will have a hard time burning around stuff, as it needs a healthy supply of oxygen.

A good substitute that i used with great success for igniting thermite is improvised fuse from a composition such as slow nitrate flash , KNO3, Al, S ratio 5:3:2, or 5:2:3, with the oxidiser lowered to , say, 4. I grind them up separately in mortar and pestle or coffee grinder, mix together by diaper method, and funnel it in plastic drinking straws :D, then gently press it with a pencil for compaction. it works like a charm.
Other possible formula would be KClO4/sucrose Or KClO3/sucrose.

Neil - 26-2-2011 at 08:04

Sulfur aluminum fuses work well.

many Sparklers are a mixture of low grade thermite and magnesium - I've never failed with one.

good sparklers are sufficiently aggressive that they will burn buried in sand or wrapped in paper.

That being said the sparks from the sparkler can ignite a finely ground pure thermite.

Matches and candles will also ignite thermite if the edge of the flame is used and the thermite is well made.

Adding catalysts such as CaF2 will also make the thermite easier to ignite.

tnphysics - 27-2-2011 at 15:51

How is CaF2 a catalyst? Is it a flux?

Neil - 1-3-2011 at 19:22

That would be my assumption. It increases the burn rate and sensitivity of thermites when used correctly. It also allows better slag/metal separation which is very useful if you are using it to refine strange things.