The Steamboating Forum

I have already asked about purging the system of water and using a heat source in the boiler for winterization and have found that our dock club sometimes looses power for three days at a time and so can not be relied upon for anti-freezing and condensation control with electric heating. It gets down to 12 degrees f. in the night time. Some days it doesn't get above 25 for two months at a time.

So now I am wondering if I could fill the system with anti-freeze for the winter and then flush it out in the spring. The only issues I have is that of getting anti-freeze inside the engine and its affect on the cylinder wall and piston rings etc and the initial running of the engine on spring start-up when there may be a slight amount of the diluted anti-freeze fluid in the system. Would it be alright to have anti-freeze in the engines piston and cylinder ?

The engine is not plumbed so that I could isolate the engine from the heat exchanger and I would have to add a valve in that line so as to have any anti-freeze in the cylinder. I would like to know what I would have to put in the cylinder chamber to winterize it after it is isolated, oil, or some fluid or what ever is proper.

Does anyone have experience with anti-freeze in all plumbing systems or isolating it from the engine its self ? Thank you DOF.

Here in the UK you can buy specific antifreeze for central heating systems- this is designed for systems including cast iron, steel, copper, brass and aluminium in their construction. I'm fairly sure that the active main ingredient is normally just glycol, but i'm not 100% on that.

Your nearest heating engineer may be able to help.

Greg

Greg, a rough equivalent here is RV (recreational vehicle) anti-freeze. At work we have used this for clients' private railroad cars that were going to be laid up for a while. It is cheaper and not as potent on various metals as automotive anti-freeze. It is pink and sold by the case wherever marine or RV supplies are sold. DOF, you could fill your entire feedwater system with this stuff. When it is steaming time, drain all that you can, add fresh feed water and then be liberal with the cylinder cocks while warming the engine. You should be okay with it.

Do be careful with antifreeze containing ethylene glycol - it is toxic to people and animals, so disposing of it requires care, and it cannot be left anywhere the animals will find it.

If I lived in an area with hard freezes, I'd be inclined to just blow out the plumbing with compressed air rather than using antifreeze.

- Bart

Ethylene Glycol, generally found in automotive anti-freeze, is toxic as stated by Bart. Animals like to lick it up too, so spills are potentially dangerous.

The RV anti-freeze solutions are Propylene Glycol, which is generally non-toxic. It would have to be, as it is used to protect RV drinking water systems from freezing, and a toxic substance here would be prohibited.

Then Ethylene Glycol it will be. The system was plumbed very carefully but not used in the cold climate where we will be using it. There are lots of drains and shut off valves all over the place and we are new to this hobby so we are asking questions before we jump into the snake pit. Thank you for your careful safety messages, we too are careful and don't want to make a mess of things.

Next we will be asking if a vacuum pump is necessary to improve efficiency at the 7000 foot altitude where we will operate our single cylinder double acting four horsepower engine.

This is one for the scientist among us Hey Fred- water should boil quicker at higher altitudes but is there a trade off? Den

The boiling point of fairly pure water drops to just under 200 degrees at 7000 feet. Doesn't seem like much but if the hot well temp was up near the limit of your feed water pump's ability to deal with vaporization on the suction side, it might cause some problems.

I dunno. Nothing new about that!

For we "Sea Level" steamers, the normal atmospheric pressure is 29.92 inches of mercury absolute pressure. At 7000 feet elevation, the normal atmospheric pressure is only 23.24 inches of mercury, so you get the equivalent of 6.68 inches of vacuum for free (no condenser, no vacuum pump), just exhausting to atmosphere. The 7000 foot elevation results in about 22% reduction in the normal "sea level" atmospheric pressure.

Most condensing steam engine arrangements strive for around 20 inches vacuum (at normal "sea level"), corresponding to 160F condensing temperature, this is 9.92 inches mercury absolute pressure. To achieve the same exhaust conditions (160F condensing temperature, 9.92 inches mercury absolute pressure) at the 7000 foot elevation, the corresponding vacuum gauge reading would be 13.31 inches of mercury vacuum. In summary, the 7000 foot elevation gets you about 1/3 of the way to the performance objective of a typical steam launch condensing setup, without the vacuum pump. To get to the typical objective, you would need a vacuum pump.

The numbers listed above are typical, but many launches run condensing with little or no vacuum reading, just to conserve boiler water.

I try to write a clear explaination, in this case, maybe "clear as mud".

farmerden wrote:This is one for the scientist among us Hey Fred- water should boil quicker at higher altitudes but is there a trade off? Den

Ya can't git something fer nuthin. Takes longer ta bile an egge! ('cause there's less BTU input)