Tips and tricks to opening mainspring barrel

[stevemilw]

Hi

I can't get open the main spring barrel on my Seiko 7009A movement. I applying pressure to the geared teeth and i'm worried I will damage them by pushing any harder. The amount of surface area to push on is very limited.

Are there any tools or tips to get this done better? with so many tools in watchmaking, it seems odd that there isn't one for this.

Currently i'm applying pressure using brass tweezers to limit damage using the hard table as the surface. 

Thanks

 

[thor447]

That is one of the barrels that separates from the edge, not from the top or bottom.  I like to use a sharp razor and a screwdriver as leverage, but you must be VERY careful when doing it this way not to mark up the side walls of the barrel.  With a light touch and steady hand they will separate.

Here's one on a 7006A (same barrel as a 7009A) I did the other day.

 

Edited April 30, 2023 by thor447

[aac58]

I do it with my finger nails, like so

 

[oldhippy]

A one sided razor blade is the best tool for this job. 

[stevemilw]

Great thanks for the pictures, really helpful!

[stevemilw]

Bought a razor, did as suggested in the picture and it worked first time. 

[DrHWO]

In a similarly gummed up 7005A (also a side opener) barrel, I too struggled. Used a fingernail to apply counter pressure to the teeth and a bed of Rodico to keep the 2 halves nearby. Worked well and no tooth damage. Needed to avoid using nail varnish the day before and a trip to the nail salon after! Used a Stanley knife blade with the cutting edge abraded flat. This successfully avoided casualty trip, transfusion and marring the barrel edge.

Edited July 21, 2023 by DrHWO
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