Thursday, 26 December 2013

Boxing Day Steam Up

 Don't forget, you can enlarge any of the pictures by clicking on them!

The Meccano "Steam Engine"
A few moths ago, Sue and I acquired a very nice collection of good quality Meccano. There were several items amongst the lot we were partially interested in. This Steam Engine was one of them. Today there was a question posted on Rust Bucket asking about how to check and fire an old engine.  That was the only excuse I needed to have a little steam up.

Nice clean burner - This is how it should look
These old engines ran on Methylated Spirit and were supplied with a spirit burner. This is often missing so If you are thinking of buying one make sure the burner is with it or haggle for a reduction - a replacement burner is going to cost anywhere between £10 and £20, for a good second hand one. Reproduction burners are available from some suppliers too. They should look clean and free from any deposits on the burner gauze. I often see these burners with the remnants of solid fuel tablets encrusted over the top. This can be removed with the application of a wire brush. This one shown here has not had many firings and so still has most of its chrome finish. This soon burns off  but does not effect the burner's efficiency.Inside the burner is a fireproof material that 'holds' the spirit. This should be slightly springy and it should be possible to depress the burners gauze easily and it should spring straight back when the pressure is released.

Most important is the fire extinguisher - AKA a plant spray, meths and rain water
We now need some fluids. The most important is the plant spray filled with just plain tap water. This is for use as a fire extinguisher, but make sure it works! some of these plant sprays need priming before they will work properly. Prime, it check it and have it ready to go. You will need methylated spirit (meths) and water for the boiler. There have been long discussions regarding what water to use. Some say this, others say that. I am not going to get into a long debate over it. Sue and I have always used rain water and it works fine for us. As Meccano enthusiasts who only use Steam engines from time to time, we may not need to worry as much about the water as someone who is steaming an engine far more frequently.

Two types of oil
Two types of oil are required. Automotive multi-grade engine oil is used to lubricate the journalled parts and 'Steam Oil' is used on the cylinder back-plate and the piston. Steam oil does not emulsify when in contact with steam as readily, if at all, as ordinary oil. It also helps to make a seal around sliding parts. Most steam spares suppliers will sell you a small bottle of Steam Oil.If you can't find any on their listings, go to eBay and search for " Steam oil" There are dozens of listings for it!

Syringes and extensions
Syringes are useful for filling the boiler with the correct amount of water and are even more useful for emptying the boiler after use. The alternative extensions are for use with different engines. The long one is for our vertical boiler engines and the short one for the horizontal boiler engines. The smaller syringe is for meths.

Safety valve has two seals
The first thing to do with any new-to-you engine, and this means brand new or second hand. is to do a careful visual check of the pipe connections and the boiler itself, looking for any damage or loose pipes. Once you are happy the engine looks sound, the next thing to check is the safety valve. Check that it operates and that it is not blocked.

If the safety valve is from an old engine, it may well be seized solid with scale. If so, just drop it in an eggcup (or something similar) full of vinegar and let it soak for an hour or so. The vinegar  will dissolve any scale and it will reappear nice and clean looking - especially after a polish with a cloth! Check that it opens, and the spring closes it. It shouldn't need any oil, but if you feel an urge to add some a spot of steam oil is all that is requited. A smear of steam oil around the threads will make it easier to remove after a steaming session. If the valve is faulty in any way, or you are not happy with it for any reason, please just replace it. They are not very expensive and easily sourced on line. You will need a Mamod style, ¼ inch short safety valve. It is better to be safe than sorry. Whatever you do, do not be tempted to run the engine without a working safety valve, or as I have seen on more than one occasion, do not ever plug the safety valve hole with a bolt to prevent it leaking. These engines are perfectly safe providing you are using it according to the manufacturer's instructions and use common sense.

Filling - the slow way
The Meccano Steam Engine takes approximately 120ml of water. The manufacturer's method of achieving this is to fill the the boiler with water, through a funnel that has been inserted into the threaded hole revealed when the safety valve is removed. Water is added until it runs out of a level hole, from which a screw plug has been removed. In the picture above a small stainless steel dish is used to catch the water. These handy little dishes can be purchased in small stacks of six from several of the pound-shop chains. Once the engine is full, the plug is replaced, the funnel removed and the safety valve replaced. It is worth noting at this point that the level hole can be found at either end of the boiler, depending on when the engine was made.

Filling - the fast way
 A far more efficent way of filling steam engine boilers (or emptying them for that matter) is by using a syringe. A measured amount of water can be added, from empty, and the level plug can be left in place - much easier.

Sue getting into hot water...
If you want to speed things up a little, hot water can be used to fill the boiler. On some engines this will save a lot of time and fuel. I have been known to do this when we are steaming our vertical engines. These take a lot longer to get up to temperature and are far less efficient than the horizontal boilers with their larger burners. I don't bother with these engines, and handling cold water is much easier.  In the picture above Sue is emptying the hot water from a vertical boiler engine using a syringe. The look of expectation on her face is because she knows that syringe is going to get very hot, any time now. I Always let Sue do the hot bits...

Adding steam oil to the back of the cylinder
Now it is time to do the oiling. Push the small bolt that retains the spring holding the cylinder against its back-plate. you will now be able to drop some steam oil between the two. An eye dropper is ideal for this and just by chance the one we have fits the top of the steam oil bottle. Any excess oil can be removed with a cloth.

Loosening the bolt (using a miniature socket) that restrains the spring
On some models it may be necessary to loosen the retaining screw in order to get enough movement to release the piston rod from the crank pin. Sometimes this is not necessary as there is enough play. If the bolt does have to be loosened, don't forget to tighten it again afterwards!  Once the rod has been released from the crank pin, the piston can be removed and the cylinder primed with steam oil.

Removing the connecting rod and the piston
A few drops of steam oil are dropped into the cylinder
Finally, lubricate all the moving parts, check that all the moving parts run freely and are not binding. A last minute check to make sure all the parts are secured to the crank rod tightly and we are ready to go!

Don't forget to lubricate the crank pin
Now the fun bit! Stand the engine on a flat surface. If it is to be run light, as here it is a good idea to stand it on a piece of non-slip mat. Fill the burner with meths. We use a small syringe. fill the burner so the meths is just visible beneath the mesh.  If you do not have a syringe, decant a small amount of meths  into a bottle cap or medicine cup and fill the burner from that.

Filling the burner - not too much
Now we are ready to go! Place the filled burner in place and using a gas hob lighter, ignite the burner. It will burn with a low flane at first and will get going once it warms up. everything will get hot very quickly from now on. Within seconds the firebox will be too hot to touch

A gas hob lighter is the perfect tool for lighting the burner
It will take four or five minutes for the water to get up to temperature. A flick of the wheel and the engine will run. If it doesn't just wait for a bit and try again. once it has started it will be off and it can be regulated and reversed by moving the lever.

A quick flick and off she goes...
There she goes - flat out!
That is it. The engine will run until the meths runs out - it is designed so the burner runs out before the boiler is anywhere near empty - ALWAYS refill the water if you are refilling the burner. If the boiler runs dry you stand the chance of over heating the joints, melting the solder and the boiler will fall apart!

Have fun - be safe and always make sure you have a water sprayer THAT WORKS to hand!

Happy steaming!

Ralph. (Hands by Sue!)


  1. How much water (in mls) does the mec1 tank hold? Reason being, I want to get a syringe and would like to know what size I need.

  2. Hi Johnny,

    Now you must go and stand in the corer repeating to yourself "I must read Ralph's posts properly" One hundred times...

    I have stated the amount under the picture of the engine with the red funnel in the filler hole...

    ... It takes about 120ml - I use a 60ml syringe. the meths syringe is 25ml.

  3. Ahh. Now I see it. Thanks for pointing it out.
    I must read Ralph's posts properly.
    I must read Ralph's posts properly.
    I must... Oh, you said repeating to myself, oops, I must read Ralph's comments properly. I must read Ralph's comments. :-)
    John snr.

  4. There's a good dad! I won't tell Johnny Jr.