How much steam oil in the cylinders when running on air ?

After weeks of filing, drilling, tapping, sanding, priming and painting, I am finally ready to begin full assembly of the PM Research 3BIM and 7BIM stationary steam engines. All the parts were fitted to each other before painting so I know everything fits together.

1. When placing the pistons into the cylinders, should I put some steam oil in there ? When eventually running under steam I will be using displacement lubricators but I intend to run them in on air for now. I was thinking that a few drops into each cylinder would suffice.

2. Can steam oil also be used to lubricate the other moving parts or should I use a light machine oil for that ?

Edited By Brian John on 18/04/2014 14:21:29

Steam oil is rather thick at normal temps but can be used if you are mixing air and steam running. otherwise use machine oil when running on air and for the other lubrication. Don't use car oil as it emulsifies with wter and looks a mess. When you get to steam it that oil will come out with the first condensate. Hopefully you have drain cocks. Your displacement oiler will put in a big gulp of steam oil too during the warm up stage owing to the way it works. You don't have to get too paranoid about oil when running light for demo purposes as wet steam is a pretty good lubricant too.

I've tended to use a light machine oil, but when you run on air, the oil does get blown out of the exhausts, so if you are planning on continuous running, you do need to have a constant injection of a small amount of oil to keep the lubrication going. There is a little in line adapter you can buy for about £3 which is normally used for air tools. It takes a small quantity of oil which gets into the airflow. Not unlike a displacement lubricator, but they don't need any heat.

Steve

I use a standard air tool oil 'Cengar' usually, its light and breaks into a fine mist and easy to wipe off.

Hi Brian

I have been building steam locos for 40 odd years and have had no problem with EP80 gear oil, if your engine has rings on the pistons then oil them and the bore when fitting, if graphite yarn then soak it well in oil and hot water first and oil bore. If your engine has piston valves then you need a good supply of oil or it will seize up.

Hope this helps as I have never built a stationary engine.

Regards

Stan

Both engines have two rings on the pistons.

Edited By Brian John on 19/04/2014 04:08:40

Yes, I see some of those in-line oilers for air tools on ebay ; they are 1/4'' BSP. Could these not be used for live steam too ? They would be a cheaper alternative to displacement lubricators if the clear plastic can take the heat.

Edited By Brian John on 23/04/2014 14:14:39