[DroopyPawn]

After being told how to get the aluminum Q-Tip off the end of my endmill (with acid) I had a part pop out before I was done cutting it. Looks like it needed one more trip around at 0.02" depth. I probably could have cleaned up the part by hand but I thought I see what happens when you drop an entire piece in acid. HCl.

So I did it.

It bubbled and spit and fumed. The remaining layer melted away and I was able to rub most of the black stuff off - at least the parts with exposed surfaces. It looks like a used part now. Kind of cool.

Do people do this very often?

[Geof]

Do people do this often? Probably not...how many people have concentrated HCl available.

Incidentally don't strike a match over the fumes or you may emulate the Hindenberg.

[DroopyPawn]

Hmmm. Guess I better quit doing this in the kitchen then.

[Splint]

I've seen this done on cylinder linings on two stroke engines when they seize and deposit part of he piston on the lining. Works well.

Splint

[warpedmephisto]

Yeah, the bubbles you saw were hydrogen as a result of the HCl and Al reacting. This is the same reaction that makes a "Draino Bomb" go boom. If you do it, do it in a well ventilated place and as always, be careful with acids. Always have some baking soda on hand if you make a spill.

[lerman]

To remove aluminum "welded" to a tool, don't use acid; use base.

I soak the tool in lye drain cleaner for a few hours. The lye will attack the aluminum, but leave the steel tool untouched.

Be sure to wear safety glasses.

Ken

[mike46]

just drain cleaner straight or mixed

[lerman]

I usually take a small juice glass, half fill it with water, then add a tablespoon or two of draino powder.

Ken

[harryn]

..how many people have concentrated HCl available.

It is a pretty common material in the US (industrially).

The main challenge of it is that the HCl molecules are able to penetrate many plastics, so it is not so simple to store without getting everything rusty.

There are sort of two theories of home acid use:
- Use all of the protective gear including aprons, etc.
- Use some of the protective gear, and routinely get rinsed down with a garden hose.

I protect my face, eyes and hands VERY well (goggles and a splash shield) but wear a bathing suit. My wife sprays me down every few minutes to keep from accumulating acid on the skin. She likes to spray me, and it helps with the buddy system aspect. It sounds odd, but it works well, esp. for acids like nitric and HCl.

Not too practical in Canada this time of year.