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WEIGHTING MODEL LOCOMOTIVES
Some model locomotives from kits have too little tension on the driver springs. The result is the same as having a ridgid frame, because the journals are being pushed too tightly against the retainer plate to alloy for any vertical motion in the axels. The solution is to put more weight in the boiler. A Cerro Alloy is used to add weight to the boiler. This low melting temperature metal is extremely useful for adding weight to the locomotive since the operation can be done on a kitchen stove or a hot plate.
If the model housing is made of plastic, careful attention must be given to the melting temperature of the alloy and the plastic. If at all possible, a temperature test of the two should be made.
Cerro Alloys are available at a melting termperature as low as 117º F. There is a big difference in the price of the alloys since the lower temperature alloys contain Indium. This element is costly on the metal market selling for about $385 per pound. The lowest melting temperature alloy without Indium is Cerrobend with a liquid temperature of 164º F and a price of about 1/4 the cost of Cerrolow 117.
To use the Cerro Alloy for weight, remove the boiler from the frame and plug all holes with regular masking tape. Heat the alloy in an old sauce pan that is sitting in a larger pan with hot water (double boiler) so that the alloy will receive evenly distributed heat.
The alloy cannot be overheated since the water will only reach a temperature of 212º before boiling. Once the alloy is liquid it can be poured. The best "rule of thumb" is to pour the alloy about 10 degrees hotter that the melt temperature. It is a good idea to use a dial type candy thermometer.
Once solid, any metal that interfers with the drive mechanism, motor or other parts can be removed easily with a warm soldering iron.
Copyright 2002-2008 by HiTech Alloys. ALL RIGHTS RESERVED. No part of this text may be reproduced in any form without permission from HiTech Alloys.