Some tips on restoring Model Steam Engines (your mileage may vary!)
dirtymount
Before I start this. let me state this very clearly: I absolutely recommend that you do not try any of this. In fact, I recommend that you leave all steam engine maintenance and repairs to suitably qualified engineers. Everything described below worked for me, but some of the methods I use may be wrong or downright dangerous.

Having said that - a few burnt fingers are a small sacrifice to make for a lot of fun - just be sensible.

Most important thing to have to hand, I think, is a good selection of lubricants. WD40 for loosening up and cleaning rusty parts. Sewing machine oil for small moving parts. Compound 680 oil for steam parts (portfaces, cylinders etc) and olive oil for cleaning and oiling brass amd painted parts prior to storage.

Hardware: a good selection of pliers and cutters. Small files are essential. The most useful thing I have is a leatherman multitool - the pliers are absolutely superb. Try not to use pliers to loosen up jammed parts, or chances are that  you'll shear them off or break the solder.
For soldering I use a small Gascat propane torch - perfectly adequate for small pipework. Never, ever skimp on preparation for soldering: make sure your surfaces are scrupulously clean and sanded, and use a good quality solder and flux. For advice on soldering, read Tubal Cain's books.
Screwdrivers of course, and small spanners are very useful. A small bench vice will save you grief, and make sure you have an appropriate stable worksurface, old newspaper and lots of rags.
If you need to reinstate pipework, make sure you have enough pipe for the job. Pipe cutters are handy, and bending springs essential - can be had from the better modelling shop, Greenweld definitely have them.
Hacksaw Junior and Senior, a good sharp knife and scissors are essential. Sandpaper and wire wool in all grades for preparing and finishing.


Painting and Cleaning: Old paintwork should be preserved wherever possible - I clean it wih a 50/50 mixture of white spirit and steam oil. Where paint is damaged beyond repair, take care in removal as old paint may contain lead. In any of this, I would advise you to work in a well ventilated space, and to wear appropriate protective kit -= I always keep a supply of disposable latex gloves.
Sanding down's the most appropriate way of getting rid of old paint, but sometimes more drastic measures are necessary; in that case Nitromors paintstripper works really well on metal surfaces. Be  careful! This stuff is corrosive and poisonous, as are the fumes! If you get this on your fingers it hurts (I know this from experience)! If you get this in your eyes you'll be blinded!

As far as painting goes: preparation is everything. In terms of authenticity I find Humbrol enamel the best choice, but for large surfaces that don't get  too hot I sometimes use spray enamel, for that smooth finish. There are a number of heatproof paints available, the most common one being barbecue paint. Make sure you have plenty of small brushes, and enough white spirit to keep them clean. Don't cut corners: proper sanding and rubbing down will save you grief later, and always allow enough drying time - at least twice what it says on the tin!





m122running
Trying out a restored engine: lots of engines are being run on compressed air, but where's the fun in that? As long as you're sensible, I think steam engines should be steamed. I use meths (denatured alcohol) by preference, as solid fuel stinks, is harmful to small animals and explodes when damp! I use disitilled or rainwater, and I tend to pre-boil it to save on steamup time.
Make sure the engine is well oiled, and keep the supply of oil up while it is running. This goes for all moving parts, including safety valves and whistles.
Once your boiler is up to steam, check very carefully for leaks or weak joins. If you spot anything untoward, extinguish the flame and don't do anything until it's been fixed. Even though model steam engines run at low pressure, I would not want to be anywhere near a failing boiler.

Once you're finished, make sure the boiler is completely emptied. Spin the engine to get rid of any condensate, and oil. If the engine's to be stored for a while, flood the cyclinders with oil and put a good squirt of WD40 into the boiler. (NB: never squirt WD40 at a running engine - you'll have an instant flamethrower, shortly before the exploding can rips off your hand and removes your face).
Clean the engine gently with a 50/50 mixture of white spirit and steam oil, or pure olive oil! Wipe off excess oil, and store in a dust free place.

One final note: these engines are toys, and as such designed to be played with - letting them linger in a display cabine does them no good. If an engine is still in a good enough state to be used, regular use will actually improve it - the heating-up and cooling-down has a mild annealing effect on brass, and tends to prevent fatigue cracking! If course if what you have is an Edwardian museum piece, out it where it belongs - in a museum.


Special Tools
395
Dremel Rotary Tool: often imitated, never equalled. Like a lot of people I used to have a little rotary tool from planet bargain, until I got fed up and splashed out on a proper Dremel, and I've never looked back. Sure it's expensive, but you get what you pay for - the power and controlability are superb, and so is the quality of the bits. Will do all your cutting, sanding, grinding and polishing, and is ideal for precision drillwork.




blowtorch
Blowtorch: I have two - a little "pencil" type for small, precise soldering jobs, and a bigger one for jobs that require lots of heat quickly (big soft soldering jobs, or small-scale brazing). My little torch runs of lighter gas, the big one uses disposable propane/butane canisters, available in most hardware stores.

Getting rid of Limescale
I recently bought an engine whose boiler was very badly furred up with limescale - so bad that it had blocked the steam outlet. I decided to use an old domestic remedy, bought a 60p bottle of malt vinegar, poured it into the boiler and left it for two nights. On the third night I gently heated the boiler (I recommend that you do this outside - boiling vinegar reeks!) and got rid of the vinegar which had turned an interesting shade of greeny-black. No more limescale!

I do recommend that you run your engines with distilled or rainwater .


Annealing copper pipe
If you've ever replaced the steam tubing on an engine, you'll know that copper pipe can be hard to bend. A nice little trick is to soften it by annealing. This involves heating your copper pipe until it glows a dull cherry red (you'll need a blowtorch - don't get it too hot, or else your copper wil melt), and letting it cool down. Repeat a couple of times. The pipe will then easily bend under light finger pressure - if you need tight bends, still use a benfing spring to avoid kinking.

DON'T cool your pipe by dunking it in water - this has the opposite result, and will harden it!


Tips by other Bowmanites
Remember when EMail was a new thing? How exciting it was to get mail from people on the other side of the planet? Well, sometimes it still happens....thanks to the few hours I've spent on this website I've had quite a few emails from a wonderful and colourful bunch of people, who have provided me with their own insights, advice and general good humour.
One such person goes by the EBay handle of "IndianaRog". Roger is a Jensen and Empire expert, but he's caught the Bowman bug. He provided me with the following tip which, like all strokes of genius, is incredibly simple and easy to do (the "now why didn't I think of that" syndrome).

Here goes:

You know how the bigger Bowmans have a sliding fit exhaust pipe to the chimney, and how condensate has a tendency to leak from the sliding joint?
Simply put a bit of heatshrink around. Tidy, unobtrusive and removed in seconds. Job done!

heatshrink


If anybody else has any tips - send them in. I'll publish them here with as much credit as you like.


Simichrome Polish
Another golden tip from Indianarog! Apparently this stuff is much beloved of Harley owners. It's pretty much an unknown quantity in the UK, but easily ordered from the US.
It is, quite simply stated, the best metal polish I've ever come across. It knocks Brasso, Silvo, T-Cut and whatever else into a cocked hat. It takes the pain out of polishing, and leaves your brass with that priceless "shiny but mellow" look, while at the same time protecting it against tarnish. I've you haven't already got some, go and order some right now. You won't be sorry.

simichrome


A Safe Alternative to Chemical Paintstripper
Anyone who's ever used a chemical paintstripper knows what nasty stuff it is....I actually managed to get quite a nasty burn from Nitromors.

On November the 6th Murray W. wrote:
"A safe and inexpensive paint stripper if you can immerse an item is pine oil. It is not available undiluted except commercially, but the solution sold as a domestic cleaner is satisfactory. Use the brand with the highest concentration of pine oil, in the USA that seems to be Pine-Sol with 15%."

Not tried this yet, but I will! If this works I'll never use Nitromors again. Thanks Murray!




Fixing a stress crack with Cyanoacrylate superglue
My Jensen #25 recently developed a couple of hairline stress cracks towards the endcap of the cylinder - as the endcap is a press fit, there is a fair bit of strain going on there, and with repeated heating up/cooling down....

Rog contributed the following on the Toy Steam group:

"
I have fixed a few Jensen cylinders with nothing more
than cyoacranalate (super glue). Of course the split
has to be minimal and in the sidewall or juncture of
the endcap on the cylinder and sidewall. Here's how I
have done it:

1) run the engine WITHOUT any cylinder oil, allowing
steam to spurt out the crack/split (unless you have a
gusher).

2) after a few minutes of this steam "enema" cleaning
out the crack, remove heat source and let pressure off
with whistle or just let it cool down

3) carefully let a little CA glue flow into the crack
which it will as the cooling down creates a negative
pressure. CAUTION...have the piston in a position
anywhere but where you are inserting glue or you can
lock it in place!!!!!!!!!!!!!  "


I tried this, and it worked a treat. Small word of warning - when the CA hits the hot cylinder, hold your breath - it STINKS!