[TheForge] Re: brill dit stock (grrr)

[xlch58 at swbell.net]

There is an old dodge for aluminum only.   Basically there are acids 
that will dissolve iron/steel and not touch aluminum.    I am not near 
my files right now, but believe ordinary battery acid will work.   I 
have tried this once with complete success.   It takes a while.   
Warming the acid works.  If you don't know the cautions that apply to 
acid, don't do it.   I have also heard that an alum solution made with 
the alum that is used in canning will also do it.   This requires the 
water to be heated to make the solution and heat continue for dissolving 
the tap, so if the item is too big, it won't work. 

Charles

Roger Olsen wrote:

>Hello Justin,
>
>I am the one who posed the original question about a broken drill bit and
>how to anneal them.  Mine was in a bar of 1 inch  forged mild steel.  I
>was hoping to take a heat on the section and anneal as tool steel.  What
>finally worked for me was drilling from the back side and center
>punching,  not as simple as it sounds cuz I had already bunged up the hole
>from the front side but it did finally work.
>
>My method soes not sound like an option for you but it looks like some
>good tips are coming in.
>
>Roger
>________________________
>
>Justin Fellenz wrote:
>
>  
>
>>Roger,
>>
>>Please share how you got that stud out. A stud just twisted off below
>>grade in an aluminum intake manifold I'm working on, so I drilled a
>>lovely, perfectly centered hole in the stud and decided--foolish me--to
>>try my handy-dandy blue-point screw extractor set, which broke off in
>>the *%)#$(#+ hole. So now I have high-carbon steel in a soft steel
>>cylinder in aluminum, flush. I can get the broken end of the extractor
>>good and red without the aluminum disappearing on me, but obviously
>>cant go hotter. I was hoping that I could anneal the extractor by
>>keeping the surrounding aluminum warm and then I figgered I'd try my
>>own idea of heating the durn thing up and then drilling. The heat runs
>>away so fast I ended up drilling while torching and the drill got red
>>real fast. Maybe thats the answer though. I'm kind of at an impasse.
>>
>>Oh, this is a manifold off an old military truck, not the kind of thing
>>I want to wreck and have to replace. Goes without saying I suppose.
>>
>>So...howd'ja do it?
>>
>>Thanks,
>>
>>Justin.
>>
>>    
>>