The greasing of fishplates requires that the plates be removed or at any rate loosened and the fishing surfaces coated with grease. This can be done with a brush but it is a slow, messy business and if the grease can be sprayed, the job is much quicker.
In addition, when spraying, it is not necessary to remove the plates completely but merely to slacken them and lever them out, as the lower fishing surfaces can then be sprayed, something which is quite impossible with a brush.
Our customer used "All Seasons P-Way Lubricant". This grease is "sprayable" and was sold to them with a sprayer to do the job. Unfortunately, they have had endless trouble with these sprayers.
With a fresh supply of grease and a clean sprayer, the system does indeed work but the difficulty is to keep it working when in the field. Ideally, you would use a small nozzle and a high pressure to give a fine spray. This is economical and clean. However, using this technique, the nozzle will repeatedly block up.
It would appear that the material simply coagulates in the nozzle as it can simply be cleared with thin wire. Experience has shown that the only way to achieve reliable spraying is to use a large nozzle and a low pressure.
The result is not so much a spray as a jet but fishplates can be greased at high speed. The consumption of grease is, however, phenomenal, amounting to something like four kegs per mile. The operators also get covered in grease which makes it a very unpopular task.
Our solution was to use compressed air as the spraying medium. We carried out some investigations and found that the grease can be readily sprayed using a standard automotive style spray gun, pressure fed from a tank of grease.
No great pressure is required and the flow of grease can be adjusted from zero to as much as could possibly be required. Operator cleanliness is assured and consumption of grease is down to less than one keg per mile, which means that after a couple of miles of greasing, the spraying equipment has paid for itself.
Above - John and Lee pose with the spraying equipment. In the background is the compressor. In the foreground, mounted on a red board, is the grease pot on the left and a cabinet containing the pressure control equipment on the right.
A close up of the grease pot and the pressure control cabinet. Note that the connections to the two spray guns are all on quick release couplings.
Inside the pressure control cabinet, showing the two pressure control valves and gauges.