This is the 2nd time I have used this technique to remove either a broken tap or stuck set screw from aluminum. If you break a tap off in aluminum, boil the aluminum part in water and Alum . It will dissolve the steel part and not harm the aluminum, with the exception that it will remove anodizing from your aluminum part.
DO NOT confuse Alum with any aluminum product, a completely different subside.
Alum, which comes in a powder and is in just about every grocery store spice isle, is the spice used in making pickles at home.
You will need a glass pan to boil the Alum saturated water in.
It took less than 2 and a half hours to completely dissolve the 3mm set screw leaving only the threaded hole, a good machinist could probably do it in less time, but given my waning eyesight I chose the Alum method.
Hope this post will get you out of a pickling situation if you break a tap off in aluminum.
Regards,
Roachcreek
DO NOT confuse Alum with any aluminum product, a completely different subside.
Alum, which comes in a powder and is in just about every grocery store spice isle, is the spice used in making pickles at home.
You will need a glass pan to boil the Alum saturated water in.
It took less than 2 and a half hours to completely dissolve the 3mm set screw leaving only the threaded hole, a good machinist could probably do it in less time, but given my waning eyesight I chose the Alum method.
Hope this post will get you out of a pickling situation if you break a tap off in aluminum.
Regards,
Roachcreek
chemistry is so intriguing 
