Center draft lamps which have been electrocuted often have the center draft tubes cut down. That is usually the end of any attempt to restore the lamp to burn fuel as replacing the draft tube is costly and difficult. The Rayo at near left still has an electric socket in the center draft tube and cut down draft tube. The pot insert at right has a cut down draft tube.

Note center draft tube is lower than the outer wick tube. Click on the photos to expand them.

Center draft tube has a ragged top.

"I am in the heavy duty truck business and we frequently have old rusty and leaky tanks sent to the local radiator shop to be cleaned out and coated with a fuel tank sealer.  The fuel tank sealer is a thick red fluid ["Red Cote"] that you pour into a tank and roll it around to cover all of the inside and then pour out the excess.  It will dry in an hour and then a second coat is applied to "seal the deal".  It is impervious to diesel or gas and kerosene of course as well.

It is not uncommon to find pinholes in the base of the fuel tank on century-old fuel fonts. First empty the font. Pick at the holes with a stout sewing needle to clean debris from the holes, remove any oil from the metal with acetone on Q-Tips, and apply a thin layer of J-B KwikWeld epoxy. In 10  minutes the leak is sealed.  J-B KwikWeld can also be used to seal stress cracks in drop-in fonts IF the stress crack is not too large and pressed inward so the finished result does not result in a wider font.

RED COTE and POR-15 are permanent repairs and cannot be reversed. For museum quality lamps that can lower the value of the lamp, if that is a concern.

If you want a simple, virtually invisible, museum quality (reversible) repair, use good old clear shellac. It seals fine cracks 100% and is impervious to kerosene.  An alcohol rinse will remove every trace of the shellac. ("Super glue" works the same as shellac for those who may use alcohol in their fuel to absorb moisture.)

Note that shellac is thin and cannot fill and seal wide cracks and splits such as stress cracks often found in drop-in fonts. Thin splits or seams such as on the fonts on student lamps can often be sealed with a simple coating of shellac carefully applied only to the seam or crack.  Note that the insert font on student lamps is inverted! If there is a tiny crack in a seam on the BOTTOM of the font there is an air leak and the proper vacuum action to only allow a little fuel out of the bottom of the font is broken, the entire font will leak out.

Click on the image to enlarge

The actual bottom of the font is on TOP, inverted, in the photo above. When inserted into the font holder the bottom of the font, which is where the fuel is filled, is placed DOWN in the font holder.

The repairs worked!  At right is the Lamp Florentine burning brightly for perhaps the first time in a century.

The two lamp stands at right were trials to see what they would look like.  The  Rochester store lamp on the left is sitting on a very ugly stand.  That one was discarded. 

The Imperial lamp on the right has a thick post-type font.  I made that stand simply by holding a chunk of cedar firewood  to a belt sander and grinding it down.  It looks pretty good, not as pretty as a lathe-turned base but not bad. 

These wick sleeve cleaners were lathe turned from broken hardwood tool handles and can be used to clean and polish the inside of wick sleeves so the sleeves slide up and down the draft tube smoothly.