Re: broken tap in alum. for CNC conversion..HELP

>--- In CAD_CAM_EDM_DRO@yahoogroups.com, "jagco1998" <jagco1998@y...>
>wrote:
> I have a small HSS tap broken off in a piece of 7000 series
>aluminum
> that I want to dissolve out using aluminum sulphate(aka ALUM), by
> boiling the piece in a solution of the alum at around 120 degrees F
> until the tap dissolves ,turning into a rusty looking color, at
>which
> point it can be flushed out with water without affecting the
>aluminum
> part surrounding it.. but I dont know what it is or where it can be
> found easily.

At the risk of this being flagged as OT you can always send the part
for anodizing. It will come back without the tap as the anodizing
process eats any steel parts away.

> I was hoping that someone could tell me what it is and maybe give

me

> an idea of where it can be found.
> Id rather not have to make the part all over agin, because I have
> quite a few hours in it.
> And being that I live in the "sticks", a tap extractor can not be
> found anywhere closer than 100 miles or so from my location.If I

was

> looking to buy a pig or some chickens..I could buy them all day

long!

> But I dont think they serve my purpose too well.
>
> Ive googled and it seems that aluminum sulphate is used in a few
> different things......
> 1) as an astringent for swollen mucus membranes.(local pharmacist
> looked at me like I was crazy when asked about it)
> 2) used in certain types of fertilizers(what kind??where to look??)
> 3)found in most baking powders (although ive yet to see a baking
> powder label that indicates this)
> But no information as to where it can be found or what to look for.
>
> Any help in this matter will be greatly appreciated.
>
> I sure would like to avoid machining another part again.......
>
> Thanks
> Jim