how long till your homemade picks were good

[Jaakko]

I just want to remind ghostman and others about the danger of grinder: Do NOT grind aluminium with a machine that has been used to grind ferrous metals or vice versa! It could potentially turn into a catastrophe when fine powdered aluminium and ferrous metal heats up due to the sparkling from grinding and ignites as a thermite mixture. About 5000 degrees Fahrenheit or 2500 degrees Celsius is not funny thing to happen inside your grinder and flashing on you

[Shrub]

You shouldnt be grinding aluminium on a grinder anyway,

[NIC]

You shouldnt be grinding aluminium on a grinder anyway,

I use to cut into aluminium with a grinder everyday. Either a grinder or a Skil Saw(circular saw). The only thing about the skil saw, it kicks alot. And when it kicks watch out. Thats why i prefer a grinder !!

[raimundo]

aluminum will fill up a grinding wheel, it chatters in a milling machine if its not lubed, and run at the right speed. it also fills up files, though if you have to file aluminum, take one stroke in a piece of chalk and then one in the metal, the chalk will fill the deep wedges of the file and prevent aluminum from binding in there. re chalk you file often. it only reduces the problem, it dosnt totally eliminate it. best cutting for aluminum is a single very sharp lubricated blade cutting a chip off or a mill wheel run at the right speed.

[ghostman]

i bought the grinder specifically for pick making, i picked it up for only 30 dollars from sears so all ive grinded were hacksaw blades so far.

[mercurial]

I just want to remind ghostman and others about the danger of grinder: Do NOT grind aluminium with a machine that has been used to grind ferrous metals or vice versa! It could potentially turn into a catastrophe when fine powdered aluminium and ferrous metal heats up due to the sparkling from grinding and ignites as a thermite mixture. About 5000 degrees Fahrenheit or 2500 degrees Celsius is not funny thing to happen inside your grinder and flashing on you

You can heat iron (or other ferrous metal) powder, and aluminium powder as much as you wish, quite safely - this is NOT thermite.

Thermite requires aluminium powder mixed with a metal oxide (eg iron oxide = rust).

Thermite composed of aluminium powder and iron oxide does indeed burn VERY hot (2500C as mentioned), and produces molten iron.

Using a grinder to grind aluminium(whether it should be ground or not) and iron on the same wheel will NOT make thermite.

Also, thermite is VERY hard to ignite, it needs a very very hot flame (such as that of burning magnesium ribbon) - again, this isn't going to happen at the grinder. You could direct the sparks thrown by a grinder at actual thermite, and it wouldn't ignite.

The grinder(and buffing wheels) certainly do deserve respect, safety wise. They certainly can be dangerous when used recklessly. Used correctly, with care, like any other tool, they are safe.

...Mark

[Jaakko]

You can heat iron (or other ferrous metal) powder, and aluminium powder as much as you wish, quite safely - this is NOT thermite.

Yes, you are right about that one. But as iron rusts due to humidity and oxygen in air, it IS thermite after that. And when you grind metal and let it get warm, it oxidises in the burning/grinding process.

Using a grinder to grind aluminium(whether it should be ground or not) and iron on the same wheel will NOT make thermite.

See above. Also interesting links to watch out: http://www.hcwg.org/grinding.htm and http://www.hanford.gov/rl/?page=542&parent=506

Also, thermite is VERY hard to ignite, it needs a very very hot flame (such as that of burning magnesium ribbon) - again, this isn't going to happen at the grinder. You could direct the sparks thrown by a grinder at actual thermite, and it wouldn't ignite.

Actually, as I have made thermite numerous of times, I can say that it ignites VERY easil when it is fine dust like in the grinder. The extremly fine dust or "soot" will ignite with a red tipped safety match and from metal sparks from grinding.

Also thermite kind of explodes if it is preheated, which can happen inside grinder due to sparkling. Though this is not necessarily the case commonly, because it ignites because of the fine dust.

[Chucklz]

Did someone say thermite?