Broken tap in titanium

[cutter17]

VICTORY IS MINE!! Last night, after 77 hours soaking in ferric chloride, I was able to tap the piece of broken tap from the hole it had occupied. Actually, the center of the broken tap came out, leaving the already cut threads still covered, but another hour took care of them, and the threads were still good as all I did was to run the tap through the hole to clean out anything remaining.

Pocket clip is solidly attached for the tip up, deep-carry I was seeking. Entire knife fits inside my pocket with only the clip showing, and I shortened the clip to 1.75" in length, and covered it with black 3M Stair Step tape to further "camouflage" it. The knife is flat so it rides unnoticed in my pocket, which is nice considering how large it is. Btw, it is a large Dozier Workhorse. I would post a picture IF I could get my camera to stop making teeny, tiny pics that will not upload to photobucket.

Again, I really appreciate all the responses and great ideas that were given. Boy, when something like this first happens you think "I have screwed up now!!", and I had, until I came here and got the information that was needed to rectify the situation.

p.s.- I wanted to see how the PCB solution would work on etching a steel pocket clip. I placed the clip in some solution, and forgot about it for 12 hours. When I went to fish it out, there was nothing but a blob attached to the bottom of the bowl I was using! Next time I try I will not leave it that long.

 

[Fellhoelter]

Pool acid (muriatic) is way faster.

Just do it outside.

Heat speeds up the process dramatically.

I used to use a coffee cup warmer, and put everything in a small pickle jar.

Come out in a few hours.

Haven't broken many since I switched to forming taps.

 

[elementfe]

I've soaked for two days in full strength Ferric and had a broken HSS tap fail to dissolve much. Apparently results vary widely. Someone, maybe Chuck Bybee, told me to clean the oxides off the surface being eaten. Makes sense, after a while the oxide layer generated by the etching process slows ferric down or even halts it. Some way to scrape or otherwise clean the broken tap fragment periodically may help expose it anew to the etchant.

I think Tinbasher's got a good point as well, you may want to degrease the area with some acetone or something to give the ferric a chance.

Would it help to degrease, or did you do that? I bet tapping oil would slow the Ferric waaaay down.
Andy