Removing an aluminum screw-up.

[Philipintexas]

We never actually “Screw-up” but sometimes unexpected things happen. Recovering from them is the real challenge.
Recently I needed to press fit aluminum “Plugs” in the end of a steel tube that was part of an assembly and offered no access to one end. Just a blind tube that was not machined inside so it was not a uniform ID.
Of course my first attempt ended with the plug tightly stuck almost all the way in, a bloodied hand from missing with my sledge-hammer persuader, no way to apply more pressure in, and no way to extract it..

After some head scratching I remembered how Muriatic acid attacks alum. I drilled through the plug with successively larger drill bits until I ended up with an alum “Tube” stuck inside the steel tube. I immersed it in a container of Muriatic acid for about 20 minutes and it dissolved the alum with no effect on the steel except to clean off the rust.

This worked for me as the steel part did not form a structurally important function and I’m not concerned about any molecular change caused by the acid..

Just something to remember and possibly help someone with a similar challenge.

DON’T do this in your shop as the acid will boil from the reaction and the fumes are extremely irritating!

 

[tornitore45]

I would have drilled and threaded the plug, inserted a screw place a wrench under the screw head and pound on it.

I would have drilled the plug to make it a thin tube cut a slit in the remaining plug and collapse it OR use a pick with a tooth ( a bent piece of scrap) and pull it out.

In a machine shop I like to avoid chemistry at all costs.