Derailleur Hanger Issue

[sjta66]

So I recently purchased a new derailleur hanger after issues with my previous hanger. After watching the video here on the site, I purchased the derailleur hanger alignment tool in order to proper align the hanger. I carefully attempted several times to tread the tool into the hangar threads but every time the connection was awkward and the hangar threads began to strip. Not wanting to ruin the threads in the hangar, I stopped (the derailleur still mounts properly into the hangar threads).

In the video (http://bikeride.com/derailleur-hanger-alignment/) he talks about how the hanger threads may not thread smoothly and the threads may be damaged and need to be chased by a tap which will be covered in a future tutorial (between 1:14 - 1:29). After searching the site I didn't see this tutorial. Did i somehow miss it?

If the tutorial has not yet been done - how do I go about chasing the treads with a tap?

EDIT: looks like I will need to buy this http://www.parktool.com/product/frame-tap-tap-10 (10mm x 1mm thread) and some cutting fluid. Does anyone have any experience having done this?

[nfmisso]

You said that the derailleur threads in fine, which indicates that the threads in the hanger are okay.

Carefully compare the threads on the tool with the threads on the derailluer - they should match perfectly. In this case it is a democracy, 2 out of 3 wins, and it the tool does not match, you should NOT use it.

[Painkiller]

it works like any other tap. if you do not have a tap t- handle call your lbs and ask how much to tap your replaceable hanger. however taping an aluminum hanger may weaken it more by shaving away precious metal. If your derailleur still goes on your tool should also. maybe cost wise buy another hanger. IF your frame was not damaged the new hanger should be pretty close to aligned.
try taking the hanger off the bike and putting it on the alignment tool that way and see if it goes on. then put it back on the bike and try again. If you think the integrity of the hanger has been compromised you must replace it with another new one because if it fails you could do far more damage to your derailleur, spokes, and yourself. I recommend to error on the side of safety but that will be your decision.
on an alloy replaceable hanger I would replace it for the safety of a customer