Nitric acid to remove broken exhaust studs

[Geronimo '74]

In another thread I saw a pic of a set of bottles (3). It was a "tap out kit"
One bottle contained a liquid with nitric acid.
the idea is to make some sort of dam (with clay?) around a snapped of stud and fill it with the acid.
It is supposed to disolve the metal stud and leave the aluminum of the head intact.
The other bottles contain a neutralizing liquid.

I bought a bottle of nitric acid today, tech grade, 61.4% (40°).
Maybe it's worth trying to remove a stud this way before I have to drill it out and risk damaging the head.


Does anyone of you know:
Is this concentrated enough to disolve a metal stud? (I'm guessing it is)
How long would you estimate it would take to disolve the stud enough to remove it??

Weird question I know...

[drew1]

I would try it on a bolt or stud of similair material & a scrap piece of aluminum before I put it on the head.

[ODDJOB UNO]

i personally would eat the acid and then get some HEAD! and say the hell with werking on cars!



once ya pour nitric acid on it, well theres no telling whats gonna happen to your head. i imagine its gonna take quite a dose and the room will be filled with vapors, and ya may end up having to buy a head anyway. let alone your next of kin may have to buy a head stone and a new head cuz yer dead!


me.........i'd eat the acid, get some head............and then drop it off at the machine shop and let them worry about it.

[old guy 53]

I have used the nitric acid with potassium presulfide and it works on 7075 alum on a 1.6 mm tap and a couple of hours . it turned the alum white (surface only) and the tap was gone and forgotten