...24 hours later the Araldite is fully cured.

Compensation Units

With the axle guards securely in place, my attention now turned to the compensation units. A number of types are available, but I find the type with inside bearings supplied by WEP are unobtrusive and go together with a minimum of fuss; simply fold up and a couple of dabs with a hot iron is enough for the solder to work its way into the folds by capillary action. A small engineer's square ensures everything is fixed at 90 degrees.

The bearings supplied (just) fit in the etched holes without the latter needing to be opened out, so that's nice and simple. A quick clean to neutralise the flux and the rocking units can be assembled by opening the holes to 0.9mm and pushing the supplied brass wire through, securing it in place by bending the ends to 90 degrees. Bob's your uncle.

Preparing the wheels

I carefully pull the wheels off the axles, and rub the backs on some 180 grit wet & dry in a circular motion to remove any casting pips and ensure the backs are flat and true. I then give the tyre fronts, treads, backs and axles a rub over with a Garryflex block (grey - medium grade), finally degreasing the wheels and axles with cellulose thinners before chemically blackening them.

There's often a lot of hand-wringing about this process, but really it's easier than falling off a log. I should say that chemically blackening is a misnomer - or should be - because that's not what we should be trying to achieve. How many prototype wheel treads are black? Exactly. What we should be aiming for is to tone down the bright shiny chrome steel of the wheels as supplied to a scale sheen appropriate for our models.

To do this I dilute Birchwood Casey Super Blue with water to a 1:9 ratio in a container and have some clean water in another container ready on the side. Lay out some paper towel and drop the axles into the solution leaving each one in there for 20 seconds. Then transfer the 'blackened' axle to the clean water and leave that for 20 seconds before fishing it out and drying it thoroughly on the paper. I then repeat the process with the wheels.

The combination of chemically and mechanically cleaning the steel, followed by brief immersion in a weak solution will darken the steel perfectly without flaking. If things are a little patchy, it's simply down to that area not being clean or grease-free, so repeat the process! I've recently seen concerns written about inserts theoretically plasticising in the solution, but in 17+ years of blackening wheels like this have encountered no such problems. Incidentally, loco wheels treads can be blacked as the process doesn't interfere with electrical pickup.

I give the axles and wheels a quick once-over with a hair dryer then fit a brass mop into the mini drill and buff the wheels and axles until they shine with a scaled down sheen. Some people like to coat them with light oil, but I rarely bother as next the tyre faces and wheel backs need a blast with the black etch primer.