Internet Horology Club 185
Some advice on removing this broken screw, please.

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https://ihc185.infopop.cc/eve/forums/a/tpc/f/3426047761/m/565106823

August 18, 2010, 01:02
Michael Overy
Some advice on removing this broken screw, please.
Hello all,

I've broken off a screw head in the plate of this Bell Matic.

The screw hole does not go all the way through the plate, so I cannot come at it from the other side.
I'd like to know how to make a spade screw bit to hopefully catch the broken one and back it out. Thought I saw someone mention using a sewing needle?
I don't have a lathe or any useful power tools, but I'd like to try to get the screw out without using chemicals, just yet.
Would white wine vinegar be of any use for dissolving the screw? I'm rather worried about harming the plate if I try to dissolve.
Here is a picture.


August 18, 2010, 11:46
Scott Cerullo
Hi,
Easiest thing, is to just order a pivot drill in the size you need from a company like Jules Borel.
You will need a pinvice to hold the bit.
Otherwise, you could drop a little bit of alum/water mixture on top of it and wait it out a few days.
Either way, this job takes a while.


www.pawatchmaker.com
August 18, 2010, 14:43
Lindell V. Riddle

Michael,

Scott's second suggestion using ordinary alum works perfectly, it is an amazingly simple process.

Alum when mixed with a little water will dissolve steel over a period of several days.

But of course drilling it out might actually be easier in some instances.

Be sure to let us know how this one "works out" for you.

Lindell

Wink

August 18, 2010, 14:51
Michael Overy
Scott & Lindell:
Thank you for your suggestions, I believe I will try the alum/water method. I fear that drilling might ruin the threads in the hole. It's off to the grocery store for me!