Spark Arrestor

Up New Life for a HOn30 Baldwin Scratchbuild a HOn30 Work Car A Steam Pump Car Steam Pump Car Part II Water Tank Car Spark Arrestor

My Mark Rollins Class A Climax needed a spark arrestor.  The problem was finding some material that looked right for the wire screen.  The answer came in the form of a Mr. Coffee permanent coffee filter that was left over from a defunct coffee maker.  I’ve looked at some others as well, and some brands seem to be made from a sheet of thin metal with small holes punched in it.  The Mr. Coffee (and my current Krups) filter is a finely-woven wire mesh – just right for HO.  There is enough material in one such filter for all the spark arrestors one could ever want to make!

I started by cutting a strip from the filter material – it is quite easy to cut with scissors and to follow along the mesh for a straight cut – for the cylindrical body of the arrestor. I overlapped the ends slightly and glued with gel ACC, using my tweezers for a clamp. Next came the solid metal bands, made from HO scale 1x4 styrene strip. This arrestor is about 0.5 inch (12mm) outside diameter; for a smaller one, a scale 1x2 might work well.  I wrapped the strip around the wire body at the top and bottom of the cylinder and secured it with ACC gel, again using the tweezers for a clamp.  The photo shows a piece of the Mr. Coffee filter material and the styrene 1x4 strip as well.
To finish the cylinder, I cut four short strips of the styrene 1x4 and placed them vertically at 90 degree intervals.

For the top, I traced the outline of the cylinder onto the Mr. Coffee mesh and cut a circle with the scissors. The problem was: how to neatly secure the top to the body? The solution is shown at right. I fitted a strip of the 1x4 styrene inside the cylindrical body, overlapping the ends slightly, and glued it with ACC. Then, I glued the resulting circle on edge to the circular top. 

When dry, the cap fitted into the body very neatly, as seen at left.
A coat of Polly S 'Grimy Black' finished the project, and the photo at right shows the result.

Materials used:

bulletMr. Coffee permanent filter (Krups has a similar one)
bulletHO scale 1x4 inch styrene strip
bulletACC gel cement
bulletPolly S 'Grimy Black' paint

Tools used:

bulletX-Acto knife
bulletSmall scissors


I liked my spark arrestor for the Climax so much that I decided to try the same technique on a new one for my 'Americanized' Egger-Bahn.  This time I cut a styrene disk that just fit inside the top of the cylinder, then cut a slightly larger wire mesh top.  I glued the mesh to the disk, then fitted the disk into the cylinder with a couple of dabs of ACC.  I also ACCed a plastic peg to the underside of the disk to hold the arrestor in place on an Egger-Bahn smokestack.

The Climax arrestor and this new smaller one
The underside, with peg and disk
The new arrestor, still not painted, on an AHM Baldwin


Photos copyright © 2005 John Hubbard
Page last changed 11/04/2008


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