Seeking advice: Knocking out hitsu ana plugs?

[Curran]

In 30 years of collecting, I don't know if I have every knocked out a plug from the kozuka or kogai ana.

 

Anyone know how it is done safely?

I'd been thinking about buying an iron tsuba with some very ugly plugs (probably early 20th century add ons to make it attractive to westerners).

 

It is a kodai tsuba, from late in the school. Ie. Not worth really sending off to an expert.

Any advice or instructions? 

 

[Matsunoki]

What are the plugs made from?

 

 

[Curran]

11 minutes ago, Matsunoki said:

What are the plugs made from?

 

 

 

I don't know. 

   It is not any easily recognizable metal.  They've been patina treated in a strange way giving a f'ugly molting color.

 

Given the patina treatment, I would guess they are copper.

There would be a total of 6 per side to knock out. It is definitely meant to tart up the tsuba.

--- Nothing precious like gold or silver. ---Nothing historical like certain type of lead or pewter plugs.

 

 

[Matsunoki]

Very often the plugs are not one solid piece but instead are two plates, one inserted from each side although lead ones are more commonly one piece (and much easier to remove)

Also how “robust” is the tsuba. Delicate sukashi with little support to/around the ana or more substantial?

Removal can be as simple as tapping it/them out if the tsuba is robust. Use a wooden dowel and support snugly and firmly around the ana underneath.

If the tsuba is delicate then great caution is wise! 
How good are your drilling skills and equipment? 
It all depends on the plug material and the strength of the tsuba

[Hokke]

Drilling out the center and corners of the plug should allow for more than enough leverage to have the plugs collapse inward with light pressure without causing any damage. 

[ROKUJURO]

Curran,

in case the ANA are plugged from both sides, the copper inserts are a bit conical, so tapping them in would need more force than tapping them out. Once you get one side out, it becomes much easier.

In older TSUBA, the URUSHI can become quite hard and brittle and will not move even with low heat. But on iron TSUBA, removing the plugs shold not be a big problem if you don't need to preserve them.

This TENBO TSUBA has lost one insert on the left side. 

[Tim Evans]

There are two types, one is solid metal, the other is 2 thin plates. Usually the 2 plate types are shakudo or some precious metal. I think this is done to reduce material cost. The 2 plate type are generally Edo period installs, the solid type could be either pre-Edo or Edo. Normally the 2 plate type are glued in with a pitch filler in between the plates, which is frequently dried out. The solid type are frequently lead or copper and are held in with a force fit.

 

Removal - As mentioned, a short wood dowel the right diameter is used as a punch. I have a block of wood with a biggish hole in it to support the tsuba, and the plug will drop through the hole. For the 2 plate type, usually these are so thin that denting them cannot be avoided. On technique to mitigate is to place the punch near the edge of the plug rather than the center and work around the circumference or go side to side and go slow. Another method is to use a thin piece of leather between the punch and the plug, until you get it moving. Usually solid lead plugs are so soft they are going to dent, but it is possible to retexture them if you decide to put then back in. 

[Curran]

9 hours ago, Tim Evans said:

There are two types, one is solid metal, the other is 2 thin plates. Usually the 2 plate types are shakudo or some precious metal. I think this is done to reduce material cost. The 2 plate type are generally Edo period installs, the solid type could be either pre-Edo or Edo. Normally the 2 plate type are glued in with a pitch filler in between the plates, which is frequently dried out. The solid type are frequently lead or copper and are held in with a force fit.

 

Removal - As mentioned, a short wood dowel the right diameter is used as a punch. I have a block of wood with a biggish hole in it to support the tsuba, and the plug will drop through the hole. For the 2 plate type, usually these are so thin that denting them cannot be avoided. On technique to mitigate is to place the punch near the edge of the plug rather than the center and work around the circumference or go side to side and go slow. Another method is to use a thin piece of leather between the punch and the plug, until you get it moving. Usually solid lead plugs are so soft they are going to dent, but it is possible to retexture them if you decide to put then back in. 

 

Thank you. There are some good ideas in here.

The leather and working around the circumference are both solid ideas.