best belts for grinding aluminum? tips?

savagesword

savagesword

Joined
Aug 30, 2012
Messages
101
Hi, I'm making some sword blades out of aluminum stock. From what I could learn from the forum, Aluminum Oxide is best for working with Aluminum bar stock.

I made a short sword blade today: 36 AO -> 120 AO -> Maroon Scotch Brite -> Teal Scotch Brite.

It came out really good.

I did notice some bits of aluminum in the Scotch Brite belts after using them, should I have a separate set of belts for Aluminum and Steel?

Thanks for your help!

shortswordAL.JPG
 
Have you got one of those gum/latex rubber blocks to clean your belt? One of those might remove Aluminum from the grit.
 
Becareful with the dust from the aluminum and steel. If the steel starts to oxidize, you can accidentally create a thermite like reaction. Maybe some makers who have had experience with this will chime in.

Stay safe!

Ric
 
Hi Phydeaux, you're right about the potential hazards of mixing AL dust and Steel dust. I just did some searching on the web and found quite a bit of safety concerns. I'm getting quite concerned now. Some machine shops have dedicated tools for AL and Steel. Other's claimed that it was too expensive to have dedicated machines, so they just cleaned up really well between jobs. Not sure if I should continue making stuff out of Aluminum.
 
You need a pretty exact mixture of rust and AL powder in order to make thermite.

Thermite cannot even be lit with a propane torch held directly on it. The sparks thrown from a grinder is not going to ignite thermite. It takes temperatures over 5000 degrees F to light thermite.

Its best to always take precautions though. If you clean up thoroughly I think you would be fine.
 
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Thanks egally08,

I'll take proper precautions. There seems to be a famous report from Australia where a worker claimed he caused a fireball from grinding steel a couple days after someone was grinding aluminum. I'm a science guy, so I can understand that some special conditions should have to be met to make this happen. It sounds like good material for a Myth Buster episode. I'll keep looking for info.

THANKS!
 
No problem. I have made thermite before, and if you do not get the exact mixture correct, which is 8/3 then it doesn't work. Also, the iron oxide and AL dust has to be mixed very thoroughly. Metal shavings won't work, it has to be actual rust.

Also, when trying to light it with a propane torch, nothing happened. I had to get a magnesium ribbon to ignite it.

I'm not saying that it couldn't happen, because I don't know how hot the sparks are, but I would say it is very unlikely, just based on my experience creating, and lighting thermite.
 
I just talked with my machinist friend and he said very similar things. He's never heard about the 'dangers' of mixing aluminum work and steel work in the same shop. But said it is theoretically possible.
 
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