There are a couple of photos
here, but not much of a "how-to".
I used brass tubing cut to length, which I then tinned on the exterior to later facilitate adding the mounting bands. The various pieces were then placed on a metal sheet and filled with molten lead. I used a pair of channel locks to hold each tube while filling - the lead solidifies as it contacts the metal sheet, and the remainder hardens within seconds. Fill each tube so that it forms its meniscus at the top - you can file off the excess later.
After everything is cool enough to handle, use a file and/or sandpaper to clean-up any excess lead or solder, then cut some Detail Associates flat brass bar (I use .010"x.018" or .010"x.030") to create the bands. I first drag the uncut strip of brass though some fine sandpaper to remove any oxidation, then immediately tin one side of the strip - you can do this to either the full strip or to individual pieces cut a bit longer than needed for each end of the air tanks. You can cut the strip easily using an old X-Acto blade, working on a hard surface - simply press down firmly using the heel of the blade and "snick-off" the required length (be sure to restrain the pieces as you cut, as they have a tendency to fly off into the unknown).
Place each strip at its position on the tank, wrapping it around and then grasping the overlapping ends where they meet using square-tipped smooth-jawed pliers - this tightens the band on the tank, and all that's required to secure it is a few touches of a hot soldering iron. Wrap this end of the tank with wet tissue, then apply the band to the opposite end. After all of the soldering is completed, use a cut-off disc to trim the protruding ends of the bands to a suitable length.
Decide what diameter wire you wish to use for the piping and drill the ends of the tanks to suit - use a bit in a pin vise rather than a motorised tool, as the lead tends to "grab" the drill's flutes, causing breakage of the bit when the drill speed is too fast.
To mount the tanks on the locomotive, select a suitably-sized piece of brass wire for a mounting pin (I use .033", .040", or .052" diameter wire from Detail Associates) and a drill hole in the back side of the air tank and at an appropriate spot on the loco. Secure the wire into the tank using ca, then test fit it to the loco, bending the wire as needed until the tank sits in the proper position. You can simply ca it in place, but I usually apply some 5 minute epoxy to the back of the tank so that it fills any voids between the tank and the boiler/running boards. Allow this to set before adding the tanks to the other side.
If you don't need to add extra weight to your locomotive, you can use Evergreen styrene tubing to form the tanks and their strip material for the bands - use solvent-type cement for assembly.
For those not wanting to do this kind of work, Precision Scale offers brass air tank kits, which include a length of brass tubing to be cut to the required length by the modeller, and various styles of cast brass ends (welded or riveted, concave, flat, or convex) which can be soldered or ca'd into the tubing.
Wayne
