This section is from the book "Soldering For Workshop, Farm And Home", by John Bonert. Also available from Amazon: Soldering For Workshop, Farm And Home - Information On Soft And Hard Soldering - Projects For The Workshop Explained And Illustrated.
Figure 27 illustrates a gas stove commonly called a "hot-plate" which is an improvement to any workshop. One burner is changed so that the flame burns directly under the soldering copper. The round burner would heat the copper but the burner shown will make quite a difference in the amount of gas consumed. The other burner of the stove can be used for heating the solder pot or glue pot. The diagram shows a fitting on the supply pipe adapted for flexible tubing but this can be replaced with a threaded fitting which would permit coupling the stove to the gas main. The writer was fortunate to have a discarded stove to work on, but a two-burner stove can be purchased for about $2.00. This small investment provides a shop stove that will pay for itself in the saving of gas. With the round burner only a small part of the flame would come in contact with the copper.
The materials needed are: 3/4" iron pipe 51/8" long, 3/4 iron pipe cap, two 3/4 45 Degree elbows, two short 3/4 iron nipples (8 threads), piece of strap iron 1/8" x 1/2" x 71/2", and one 10x24 round head machine screw.
The 3/4" pipe can be prepared first. One end is threaded to receive the pipe cap. The other end must be threaded smaller than standard. Scribe two parallel lines 1/4" apart lengthwise on the pipe for the holes of the burner. Make a center-punch mark on one of the lines 1 1/4" from the end which is to receive the pipe cap. On the same line from this punch mark make five more punch marks 5/8" apart. Measure 1-9/16" from the same end on the other line and make a center-punch mark. On this line from the center-punch mark make five more punch marks apart. Next, drill holes at these punch marks with a Number 27 drill. Screw the cap on the end that has the standard thread. Next, bend the piece of band iron as shown in Figure 27-D. This should fit over the pipe snugly. On the bottom of the bracket directly in the center drill a hole with a Number 9 drill through which to put the 10 x 24 screw. Slide the bracket over the pipe up to the cap. Directly opposite the burner holes which will be the bottom of the burner mark through the hole in the bracket. Drill a hole with a Number 23 drill on this mark and tap it for a 10x24 screw.
Figure Number 27-E shows where the two 45 degree elbows are to be cut off. With a hacksaw cut the shoulders off square. This is done to shorten the elbows (it may be possible to use these elbows without cutting). It will depend on the type of stove being converted. Enough thread will remain in the elbows so that a nipple will connect them. The thread in the elbows is tapered so that cutting the shoulders away leaves the smallest part of the thread. For this reason the thread on one end of the 3/4" pipe has been cut smaller than standard. For the same reason two short nipples will have to be threaded small enough to enter the elbows. One very short nipple to consist of eight turns of thread is used to couple the two elbows, four threads being screwed into each elbow. The elbows should be as close together as possible. The reason for using these elbows is to raise the burner about 11/8". The other nipple is also very short and is screwed into the end which is to be connected to the stove. Cut the nipple off after it is screwed into the elbow. Let it extend 1/8" outside the elbow. It is best to fit this nipple over the old burner where it will be cut off, before it is screwed into the elbow. This should be a reasonably tight fit. The mixing tube on some burners is larger and the nipple may not be needed.
The burner is now screwed into the remaining elbow thread so the whole assembly will look like the drawing Figure 27-C. Figure 27-B shows the burner removed from an old type stove. The burner is cut off where shown and the new burner is slipped over the end as shown in the assembled parts Figure 27-B-C-D. Burners on the more modern types of stoves are shown in Figure 27-F. It will depend on the diameter of the mixing tube at the point where it is cut off as to whether the new burner is to be fitted over the end or inside of it. If it is to go inside, the nipple in the elbow of the new burner will have to extend at least one inch so it will extend into the mixing tube. For this more modern type of stove the 3/4" pipe used as a burner may have to be longer so that it will extend to the back of the frame where it is supported. Figure 27-A shows two holes drilled in the frame of the stove. A piece of iron wire is passed through these holes and twisted under the cap of the burner to support it. If any trouble should be encountered with the flame the air opening can be. adjusted to exclude some of the air. This is not likely to occur as three of these stoves have been changed without any trouble. This burner can be used with either manufactured or natural gas. When buying a stove be sure to state whether manufactured or natural gas is to be used.