View Full Version : Alum

Allan Waterfall
06-19-2004, 06:07 AM
A while ago I seem to have read about getting broken taps out of aluminium by soaking in Alum to dissolve the tap.
Can anyone tell me what Alum is in England,because I asked at the chemists and got a blank look,I would imagine it goes under some proprietory name,but I have no idea what it might be?
I saw a TV program the other night and apparently it was used in the wool dyeing process.
Is it classed as a dangerous chemical?


[This message has been edited by Allan Waterfall (edited 06-19-2004).]

06-19-2004, 06:42 AM
Alum should be available in the grocery store in with the canning supplies. It is used in pickling.

Allan Waterfall
06-19-2004, 07:00 AM
Thanks JC,

However I have never seen anything called Alum on any shelves over here,neither has my wife. http://bbs.homeshopmachinist.net//confused.gif


06-19-2004, 08:32 AM

Here alum is usually found in the spice section at the grocery store.

You many want to look at a cook book for a pickle recipe and see if you can find your name for alum.

Forrest Addy
06-19-2004, 09:04 AM
Aluminum disulfate


J Tiers
06-19-2004, 09:11 AM
It is also a component of self-rising baking powders, I believe. Another possible source for your name for it.

Ted Coffey
06-19-2004, 11:46 AM
It used to be put on serious cuts to stop bleeding so it is not toxic. I know because it was applied to me when I had an accident.

[This message has been edited by Ted Coffey (edited 06-19-2004).]

[This message has been edited by Ted Coffey (edited 06-19-2004).]

06-19-2004, 11:53 AM

Try the local chemist.

06-19-2004, 01:26 PM
Does "tawas" sound more familiar?

I did a little researching on this and found that alum is named "tawas" in some parts of the world.


06-19-2004, 02:11 PM
Alum is used as a coagulant in water treatment plants. You might try calling the local water plant and see if you can get a small sample of it.


Allan Waterfall
06-19-2004, 05:48 PM
THANKS to everyone for all the replies.


06-19-2004, 07:10 PM
Something really neat with alum,

when you have some tool steel too hard to scratch with a file, take it and get it light red and pack it into a bucket with alum. It will suck any case-hardening out of the metal where it can be cut with a saw, filed or ground easily.

Rehardening is much harder, you need carbon packing or oil quenching to get the carbon put back into the metal.

Cool it slowly, anneals or softens, hardens by cooling or quenching it rapidly.

This was showed to me by a old guy who helped me out a lot.