How to make an eternal log and how much wood you can save with it

The controlled supply of water vapor into the firebox helps to prolong the burning of wood and increase the heat transfer from the flame to the brickwork or metal parts of the boiler. To achieve this effect, the “eternal log” device is used. If you have an angle grinder, a drill and electric welding, you can do it yourself, thereby saving about 15% or more on firewood.

Materials:

• steel pipe d72 mm along the length of the firebox;
  
• thick sheet metal for pipe plug;
  
• steel angle or tire;
  
• nut and bolt M16;
  
• steel rod d 6-10 mm.

Making Everlasting Log

First you need to cut the pipe to the length of the firebox. Ideally, it should be equal to commonly used firewood. 2 circles d72 mm are cut out of thick sheet metal and welded at the ends of the pipe.


To prevent the log from turning over, 2 legs are welded to its bottom. They can be made from a corner, reinforcement or tire.

A hole is drilled at the top of the workpiece with a 16 mm drill. A nut is docked and welded to it. The result is a filler neck. An M16 bolt is used as a cover.

So that you can twist it by hand, you can weld a piece of rod or fittings to the head.

At the top of the log, one row of holes is made with a 2 mm drill. The drilling step is 4 cm. Steam will subsequently escape through them.

How it works

Water, preferably hot, is poured into the log through the neck. The bolt cover is screwed on and the device is placed in the firebox along with the firewood. After igniting the boiler, water from the eternal log begins to evaporate, affecting the combustion process.

What a savings

To evaluate the effectiveness of an eternal log, you can do a comparative experiment using the same amount of firewood. On the first day, light a cauldron with logs, measuring the resulting temperature and burning duration, and on the second day, light the stove without a device. In my case, with an eternal log, combustion at almost the same temperature lasted 15% longer. This is savings on firewood, allowing you to use much less fuel over the winter.

This device really works, but it should not be used in old-type stoves. Unburnt water vapor will make the soot sticky and lead to condensation. If there is a straight flue coming out of the boiler, then an everlasting log is ideal. In a long chimney with many channels, the device will be more trouble than it is worth.

Watch the video