Stainless Screen Wicks for Aster Locomotives
by Jeff Runge
This approach offers an alternative to other traditional wick materials. In the early days of Gauge 1 Steam, screen wire wicks were used. This traditional variation on alcohol firing is not intended to correct other problems such as drafting, poor fuel quality or mechanical issues. I have used this method for ten years and now stainless screen wicks are my only approach. The advantages are many:
· Stainless wire wicks do not drop out when transporting the locomotive.
· To quickly correct water accidentally spilling on a wick, you simply flush out the wick with alcohol.
· There is no need to dry out the wick, such as is required with other materials.
The challenge with stainless steel wire wicks is in the installation.
First you must find a supplier for stainless screen wire from which to fabricate the wick. The critical issue here is the size of the mesh., Wick material should be about 80 per inch mesh. You need a good magnifying glass to count them! Coarse wire does not work for wicks.
Perhaps you can find a source for stainless steel screen wire wick from a local supplier. For the live steamer, the question is do they sell in a small enough amount, so that you are not purchasing enough screen to meet your need beyond eternity. You may wish to do a web search for “stainless steel cloth.”
Here are a couple of web links that appear to offer the type of stainless steel screen wire needed.
Once the screen wire is obtained, cut the material to size. I have found a square foot of material is more than enough to do a locomotive, such as an Aster USRA Mikado or Berkshire. Naturally, the size of the burner cup, determines the amount of material needed.
Cut the material into 12 inch strips length and with a width for the wick height matching the same as the original wick height on your alcohol fired locomotive (12 or 14 mm above the cup). Roll the screen wire strip length wise as tightly as possible. The total diameter should be the amount as if you were going to fit it directly into the burner cup. You may wish to temporarily secure the roll with wire or tape.
Place the roll in a sturdy bench vise and crush as flat as possible. Remove from the vise and unroll.
Starting from the other end, roll backwards with the previous inside of the roll now being on the outside. Roll back up tightly. The pleats in the wire prevent the layers of wire from flat against each other. The pleated space between the layers provides capillary for the alcohol to move from the bottom of the burner cup to the top of the wick.
Slide the roll of stainless steel wick into the burner cup. Temporarily wrap the exposed portion with tape, so it maintains its diameter on the outside or top of the burner cup.
With a Dremel cut-off tool and wearing eye protection, cut a “U” shaped notch (similar to a “cartoon” shaped mouse hole.
With the “U” notch straddling the transfer tube in the burner assembly, push the stainless steel wire wick all of the way down.
Once the stainless steel wick is seated in the burner cup and you are satisfied with the wick height, remove the tape. However, should you need to trim the wick, keep the tape in place and use your Dremel cut-off tool to adjust the height.
Now install the burner into your locomotive. The stainless steel screen wire wick is applicable to other alcohol fired locomotives, including the Aster Mikado. The photo illustrations with this article used an Aster Mikado burner.
For Aster Berkshire operation, I have found a silicon tube extension (attached inside the original alcohol fueling tank) can be lengthened by an eighth of inch (1/8). This reduces the amount of fuel supply to the wicks, thus reducing burner heat. Therefore, a longer run is produced on a tank of fuel.
Southern Steam Trains LLC expresses appreciation to Jeff Runge for sharing his insight and expertise on stainless steel wire wicks and for allowing us to post this article on our website.