Zenith Wax-Paper Capacitor Restuffing

My antique radio restoration logs

Here is my process for restuffing Zenith and other wax-sealed paper capacitors in order to maintain the original under chassis appearance of the radio.  In cases where an original Zenith capacitor has been replaced during servicing, I try to find a suitable original dud in my parts bin and restuffed that capacitor.  I collect branded capacitors (Zenith, Philco, and others) just for this purpose.  I have been able to purchase Zenith and other branded duds from collectors who do not restuff capacitors on Antique Radio Forums and on eBay.  In most cases I found a dud with the part number listed in SAMS or Riders/Nostalgiaair.org.  If I do not have the exact part, I substituted a capacitor with a similar Zenith part number having the same capacity and voltage rating. My re-stuffing process is as follows:

• The original capacitor is removed from the radio, and the required lead length and any spaghetti sleeving use and its length noted.  I also document which capacitor lead (outside foil) goes to which terminal.
• The low melting point wax from each end is melted and removed using an old 25 watt soldering iron.
• The original wire leads are removed, as well as any remaining wax.  The leads are normally attached to the foil roll using a low melting point metal or solder.  The heat of the soldering iron used to remove the wax will normally release the leads also.
• While the wax is still molten, a small screwdriver is used to push out the original paper-foil roll.  In some cases, the contents comes out when the leads are pulled out.
• The original cases are then cleaned out, and any wax and dirt on the outside removed by gently heating the body over a small alcohol lamp and wiping with a paper towel while still molten.  At this point, the cases look like this:

• If the required lead length is longer than that of the replacement capacitor, a piece of bus wire is attached before re-stuffing (the splice being hidden inside the case).
• The replacement capacitor is wrapped in a narrow strip of paper towel in order to keep the new capacitor centered and to keep it from falling out.  Here are the finished capacitors from another Zenith before sealing the ends.

• The finished capacitor is then sealed with melted rosin (salvaged from early RCA Superhet catacombs, and donated by or purchased from members on Antique Radio Forums).  I do NOT recoat the outside of the rebuilt capacitors with wax (I'm not sure what was originally used - probably beeswax).