Removal of rusty wire
from ceramic bottle caps

For this work I carved the shape of a ceramic beer bottle cap out of a piece of timber. The shape nicely fits a ceramic cap (Fig. 1). Exactly at the position of the hole of the ceramic cap there is drilled a hole into the timber within the carved mold. By repeated use the mold even better fits to ceramic caps. Ceramic caps differing significantly in their shape require a separate mold to be carved out. The most important tool to finally remove the rusty wire from old ceramic caps are pin punchs (pin removing tools) of different sizes (Fig. 2), which can be bought in hardware stores. The diameter of the pin punches should not be greater than the diamter of the hole in the ceramic caps (Fig. 2).

Ceramic caps from the U.S.A. usually have no round shaped holes but triagle-shaped holes. I have no exprience with removing rusty wire from such ceramic caps and I am not sure if the method described here also works for US ceramic beer bottle caps.
Fig. 1  timber with carved out shape of a ceramic bottle cap
 pin punches / pin removing tools are the most important tool to remove rusty wires from ceramic caps Fig. 2
If the rusty wire does not move even after several forceful punches with a hammer (Fig. 5 shows a rusty wire which just starts to move), one can try to treat the rusty wire some rust remover solution. It is best to apply the rust remover only onto one side of the rusty wire and then wait until it appears at the opposite side of the hole of the ceramic cap. This ensures that the rust remover went through the whole ceramic cap. Then you try again, if you can punch out the rusty wire. In most cases the rusty wires can be removed without rust remover. Some can only be removed with the help of rust remover and in a few cases it will not be possible to remove the rusty wires. In general when using this method only very few ceramic caps will break.
Using a pincer you first should pinch off any protruding wire. Subsequently remove from one side of the hole of the ceramic cap as much rust as possible down to the smalles diameter of the hole of the ceramic cap. This can be done for example using a small screw driver, such as the ones used by clockmakers. Fig. 3 shows this exemplarily by depicting a broken ceramic cap containing a rusty wire.
 Removal of rust on one side of ceramic cap Fig. 3
Next the ceramic cap is put into the wooden mold with the rusty wire placed exactly above the holed dirlled into the mold. The side of the ceramic cap on which there has been removed part of the rust should face to the top. Now you place a pin puncher onto the rusty wire and carefully hammer onto the pin puncher in order to force the rusty wire out of the hole of the ceramic cap (Fig. 4). If you place one or two layers of air bubble foil beneath the wooden mold, this reduces the noice and helps preventing the ceramic cap from breaking. Most likely this also preserves the surface of the desk onto which you are working and helps to prevent any trouble with your spuse.

During this work you should take care, that at the back of the ceramic cap the punched out rusty wire fitts into the hole drilled into the timber mold. Also the pin puncher used should not have a diameter bigger than the diameter of the hole of the ceramic cap.

Fig. 5. shows the back side of a ceramic cap treated as descirbed above. You can see, that the rusty wire has already been pushed out a little bit out of the hole of the ceramic cap.
Fig. 4  Pushing out of the rusty wire rusty wire pushed out a little bit (see arrows) Fig. 5
Fig. 6-9 show coross sections of a ceramic cap during removal of rusty wire using a pin puncher. The pictures were "simulated" using a broken ceramic cap with rusty wire insice. The finally removed rusty wire partially has a glass-like shining surface (Fig. 9). This indicates that the rusty wire has at least partially a very smooth surface, not as rough as one would imagine initially. The may explain, why the whole procedure of pushing out of the rusty wire works.
Fig. 6  Pushing out of rusty wire, seen in cross sections of a cermic cap (I) Pushing out of rusty wire, seen in cross sections of a cermic cap (II) Fig. 7
Fig. 8  HePushing out of rusty wire, seen in cross sections of a cermic cap (III) Pushing out of rusty wire, seen in cross sections of a cermic cap (IV) Fig. 9
This method most likely will not work with the type of square-shaped ceramic bottle caps, which usually were used for mineral water, but which for example in Denmark were also used for beer bottles. Square-shaped ceramic caps in general are much more sensitive to breaking, as compared to Hutter-type (round-shaped) ceramic caps. Furhtermoe the holes in square-shaped ceramic caps are smaller and are not centrally located in the ceramic cap, but at one end of the square-shaped ceramic cap. For this reason I pesonally so far use the described method only for Hutter-type ceramic caps.

Removl of rusty wire has several advantages:
  • The ceramic cap looks nicer
  • Sharp-edged rusty wires no longer can scratch other ceramic caps
  • Continued over time accumulation of rust no longer can result in bursting of the ceramic cap
Over time continued rusting of wire may result in an increase of the volume of the rusty wire. Finally the volume may increase so much, resulting in bursting of the ceramic cap. This happened from time to some ceramic caps of my collection, espcially if the ceramic caps were stored in humid climate (e.g. a humid basement or attic or in a room with varying temperature). Such storage conditions promote rusting. This in turn means, even if some ceramic caps break durig removal of rusty wire, in the end this procedure may save more ceramic caps from breaking.

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