Choosing the Correct Size for Kerosene Lamp Chimney Replacement

Borosilicate Glass Chimneys - Chimney glass can be made of either Borosilicate or soda lime material. We choose borosilicate glass because of its superior characteristics such as: 

• Free of bubbles, streaks, cords, and debris
• It has very clear color
• It is very heat resistant similar to pyrex
• It has consistent thickness throughout

We believe our borosilicate glass chimneys are of superior quality and may be the best available.

Lamp chimneys are, relatively speaking, fragile and must occasionally be replaced. If you have pieces of the damaged or broken chimney you may carefully place them together (taking care not to cut yourself), tape them together with scotch tape and measure for a replacement. If the remnants of the broken chimney are not available you may instead measure the oil burner itself to determine the correct base diameter for the replacement chimney (see fig. 1). 

Fitter (Base Diameter)

The most important dimension to consider when measuring for a replacement chimney is the base diameter (see fig. 2). The base must fit correctly to insure that the chimney is held snuggly by the burner or gallery and will not fall when moved or jostled. In addition, and most important when fitting a chimney for oil or kerosene use, the chimney must “seat” correctly on the burner hardware to promote bright and efficient combustion of the lamp fuel.

• Fitter also means Base Diameter. 

With the help of a glass chimney, kerosene lamp burners are able to draw the oxygen they require for combustion through perforations below the combustion chamber. A well-fitting lamp chimney augments this basic design by facilitating an “updraft” which continues through to the top of the chimney. This updraft helps to cool the metal burner and foster a steady, flicker-free flame..

If, however, a poorly-fitting chimney is used, some amount of air will invariably enter the combustion area around the wick from the bottom edge of chimney. When this happens, the flame is pushed about in a cross draft and cannot burn in a bright, steady manner. This “candle in the wind” effect, in most cases, will seriously degrade the efficiency and light output of the lamp.

In sum, pay special attention to the chimney base-size and fit when replacing a lamp chimney. This fit is critical for the proper functioning of your kerosene burner.

The final step in replacing your lamp chimney is to “try it on”. The best fitting chimney, when placed on the burner, will engage the tines (see Fig. 1) and cause them to bend outwardly by approximately 1/8” to 1/4” of an inch. 

The outward pressure that the kerosene lamp chimney places on the tines not only creates a firm hold on the light, fragile chimney but also helps center the base of the chimney to correctly “seat” itself and insure a proper "draft" for the burner. Sometimes these tines need to be slightly re-shaped or bent where all four exerts equal pressure on the chimney.

The correct chimney height for an oil or kerosene lamp is not only a question of aesthetics but, in some cases, may determine the efficiency of the lamp burner. Generally, kerosene lamps at use in higher altitudes require taller chimneys for the most efficient combustion. Most probably though, only lamps that employ the use of “mantles” (Aladdin or Coleman type lamps) for high light output are more seriously affected in this regard than lamps that use flat wicks.

Glass chimneys used on electric lamps are mostly for decoration, though some function as lampshade support. Here, a snug fit to the lamp and correct height (for aesthetic reasons) should be the main concerns. Many electric lamps that require chimneys have a gallery or “cup” type chimney holder (see fig. 3).

To choose a correct chimney for these lamps, measure the inside diameter of the gallery. Again, a correctly fitting chimney will engage the tines of the gallery or cup, creating outward pressure on the tines that, in turn, provides a firm “grip” on the chimney base.

Frequently Asked Questions

- How tall does my chimney need to be?

To look well balanced and proportionate, we think a chimney should extend from about 3” to 4 ½” above the top the shade on a full sized lamp.

If your lamp sets on a table and has a burner or adaptor then it probably requires a lamp chimney. For choosing the correct chimney height for your lamp’s glass shade, the following chart should be helpful.

First measure your glass shade if you already have a shade. (If you are buying a shade, refer to the fitter or the diameter information given in the product’s description.)

• For half shades (shades that are not ball shaped) measure the outside diameter of the shade’s bottom fitter. (measurements noted are close approximates)
  3 ½” to 4” diameter shades are for miniature lamps – choose a chimney that fits your miniature burner
  5 ¾” to 6” diameter shades, choose a 6 ½” or 7” height chimney 
  6 ¾” to 7” diameter shades, choose a 10” height chimney
  9 ¾” to 10” diameter shades, choose a 12” height chimney
  9 ¾” to 10” diameter shades designed to fit Aladdin brand lamps
  choose a 12 ¾” to 13” height chimney 

• For Ball shades (shades that are ball shaped) measure the overall 
  height of the shade (measurements noted are close approximates)
  
  

  Ball shade height	Ball shade standard	Choose chimney height
  7 ½” height =	8” dia. ball shade	12” height chimney
  8 ½” height =	9” dia. ball shade	12” height chimney
  9 ½” height =	10” dia. ball shade	12” or 13” height chimney
  10 ¼” height =	10 ½” dia. ball shade	13” or 14” height chimney
  11” height =	11” dia. ball shade	14” height chimney
  12” height =	12” dia. ball shade	14” height chimney