Retrol EngineDIYshop SE-03 Small Modification

[Blue HeelerParticipant @blueheeler]

This is a small modification that I have made to the SE-03 because I’m dropping the firebox out on a regular base’s because I’m mostly using hand sanitizer gel with 75% ethanol as it’s worked out for me as just the perfect fuel for this steam plant with plenty of steam pressure and good powerful runs for around 20 minutes. A simple mod turning down some brass and parting it off so that the risers were 3mm gave the perfect clearance to the boiler base of the plant and now the firebox is a quick and easy removal.

 

https://www.youtube.com/watch?v=BKJi4JgKCtA

 

 

 

 

[richarddParticipant @richardd]

Hi.  How are you finding the governor?

Mine spins fine, but doesn’t seem to have any effect on the amount of steam going to the cylinder – whether it’s rotating slowly or going “balls out”.

Second question.  Now I have managed to seal the leak from my pressure gauge (the brass insert at the 90 degree elbow fell out – clearly not a good seal from the factory), I’m seeing steam escaping from the piston valve to the steam chest.  Should I be taking it apart to see if there is anything I can adjust?

FWIW, running on bioethanol with a small carbon felt wick, I’m getting about 12 minutes run time from the burner and about ten minutes of steam power.  I’m running out of heat well before the boiler runs low on water.

 

 

[richardd]

On richardd Said:

Hi.  How are you finding the governor?

Mine spins fine, but doesn’t seem to have any effect on the amount of steam going to the cylinder – whether it’s rotating slowly or going “balls out”.

Second question.  Now I have managed to seal the leak from my pressure gauge (the brass insert at the 90 degree elbow fell out – clearly not a good seal from the factory), I’m seeing steam escaping from the piston valve to the steam chest.  Should I be taking it apart to see if there is anything I can adjust?

FWIW, running on bioethanol with a small carbon felt wick, I’m getting about 12 minutes run time from the burner and about ten minutes of steam power.  I’m running out of heat well before the boiler runs low on water.

 

 

G’day Richard,

I haven’t had any problems with my pressure gauge. I would very carefully take it apart and see if you can find the problem.
The governor is a nice addition, but like you, I’ve noticed it ‘operates’ but doesn’t actually do all that much.

In regard to your running time –

I have run mine on just straight metho(meths) in the burner tray.

Wood fired

I made up a ceramic burner and ran it on gas

and used hand sanitizer gel (75%)

By FAR the best fuel has been the hand sanitizer gel. Filling the burner tray with hand sanitizer (burns nice and blue and with a very hot flame) will bring the boiler up to operating temperature and I get a 16-20 minute run with the light on and with a lot of power and the pressure gauge not dropping and by the time the hand santizer is burnt off there is still enough water in the boiler with no chance of it running dry.

Gas fired –

Wood fired –

Hand Sanitizer fired –

[richarddParticipant @richardd]

My basic Chemistry knowledge tells me that there’s going to be very little difference between running on meths, bio-ethanol (as I’ve been using), or hand sanitizer gel – that they all contain pretty similar levels of energy.  That what we’re really seeing as a difference is how fast that energy is released – which I think is pretty significant due to the boiler design (about which I know next to nothing, but can speculate).

Bio-ethanol is a great fuel to use in my alcohol stove when camping; it burns quite fast and hot.  But I think in the SE-03 it was burning a little too fast and hot – sending a lot of its heat energy straight up the chimney.  Hand sanitizer gel is usually a pretty mediocre fuel for camping stoves (it works, but it’s a bit slower – and a bit messy).  I’ve yet to try classic methanol – there’s some on its way to me – but in theory it should be almost identical to the bioethanol.

So what I’ve just tried is to slow down the speed of combustion – and reduce the height of the flame – to give the fuel a better chance to heat the boiler.  Using that Trangia-user’s old stand-by, a “simmer ring” – a metal lit to the fuel pan that reduces the surface where the fuel is actually burning.  I my case, I used a hastily-repurposed mince pie case, with a 3/4″ hole cut in the top.

And although it took longer to bring the water to a boil (by a minute or two), the result was that the fuel burned for longer and the steam engine ran for much longer as a result.  Of course I didn’t have a stopwatch on it, but I’d estimate 20 minutes or more.

So the next steps will be to repeat the experiments (with and without a simmer ring, bioethanol versus meths), then try a few different sizes of hole in the simmer ring (and maybe some different patterns), before having a go at making something a little more permanent.  No real workshop facilities here, but I do have a pillar drill, so it’ll be a case of finding a metal disc of the right diameter and drilling a few holes in it 🙂

[Blue HeelerParticipant @blueheeler]

Richard, experimenting like above is what makes this hobby so much fun.

The SE-03 is a superb steam plant the way the vertical boiler is constructed especially once the simple mod has been done to lift the boiler height by 3mm in my case to allow easier removal of the fire box.

I’d be very interested to keep reading your adventures and findings that you discover with your SE-03.

A 20 minute run is superb, did the pressure gauge stay high and did you have the light switched on?

[richarddParticipant @richardd]

Hi.  I’m taking about 4-5 minutes to raise steam, and around 15 minutes of working time – with or without the light on.

After a little bit of tinkering I found that the burner tray worked best packed with carbon felt wicking material, and a fine steel mesh on top.  That way the fuel vapourises nicely on ignition, and spills are much less likely if the model is knocked or moved when full – although it does reduce the burner’s capacity by about 5ml.  Our meths also burns cleaner (and with less ferocity) if it’s diluted with 10-20% water.  But even using under 35ml of watered-down fuel (so about 30ml of meths) it’s generating enough steam that I’d worry about the boiler running dry if it wasn’t full to very near the top of the sight gauge at the start of the run.

I found that the burner would slide out from under the boiler without needing any modification, but the thumbscrews needed to be wound out almost fully; otherwise, the small amount that they protruded from the burner’s base was enough to raise the burner lip to the point where it wouldn’t slide out from underneath the burner.  Shame that Retrol didn’t build in a couple of millimetres of extra clearance, though (and similarly, I have to remove at least one thumbscrew entirely or the burner won’t drop onto the base of the machine; smaller diameter thumbscrews – or a small notch on the boiler base plate – would have eliminated this issue.  Next time I feel in the mood I’ll take the base plate off and grind some suitable notches in it).

Only three other tiny mods here; first, I took out all of the brass fittings to the boiler, and reassembled them with some Loctite thread locker – that eliminated most of the leaks (I also needed to threadlock the steam pipe into the steam chest – which is only a press-fit – as I was getting leaks there too).  Second, I insulated the steampipe with some silicone tubing (more for the visuals than any real effect I suspect). Thirdly, I swapped the steam pressure gauge and the steam whistle positions around; that way, it’s easier to get to the whistle in use.

At some point I’d like to see what I can do about the steam escaping from the steam chest where the piston valve runs back and forth; I’m losing a noticeable amount of steam there, before it gets a chance to drive engine.  But before I attempt that, I really ought to find out what is used as the gasket material on the cylinder head.

[Blue HeelerParticipant @blueheeler]

G’day Richard, some handy mods you’ve done.

These kit engines are a lot of fun aren’t they. Some people have mentioned that they did my mod after seeing it and raised their boiler and others like yourself have said that they have clearance….I wonder if Retrol changed something mid manufacturing?
I’m not getting and steam escaping from the steam chest, I am using 600w steam oil, maybe that’s contributing to making mine more steam tight?

I do mix water with metho for some of my older antique German steam engines to make the heat more manageable on older boilers. Of all the different heating methods I’ve tried, the hand sanitizer gel has worked for me the absolute best.

Yes, I’m going to do the same re: grinding some notches deeper to make it easier to drop the burner tray.

The “carbon felt wicking material” sounds very interesting, where did you procure that from Richard?

I do wish the sight glass tube had a blow down like my other boilers do, I keep getting a bubble in mine that makes gauging just how much water I actually do have in the boiler difficult.

[richarddParticipant @richardd]

Hi.

The carbon felt is usually sold as “welder’s blanket” or something similar – it has a high melting point, making it ideal for use in alcohol burners.  Sometimes people use fibreglass (but that has a lower MP, and will degrade over time) or ceramic wool (which has nasty fibres – not something that’s much fun to handle).  Ceramic wool has slightly better properties – carbon felt shrinks over time – but the handling risks outweigh the benefits IMO.  Especially as I usually use a small aluminium makeup tin as my stove when I’m camping (very lightweight, very low volume).

Yep, running some steam oil in it – usually just by topping up the displacement lubricator (something else that could have done with a drain cock).  I put a drop in the pressure gauge from time to time – that’s improved its accuracy!  The fact that Retrol included both features on this engine was a real selling point with me.

Like you, I’m constantly plagued by bubbles in the sight glass; perhaps they choose too narrow a tube; I’ll give the inside a clean next time it’s apart in the hope that it’s just some manufacturing residue that increases the surface tension of the water.  I’ve almost zero engineering experience or tools to make any real changes, like drain valves, myself.  My side hustle involves 3D printing though, so I have made a rudimentary steam condenser and oil trap using an old jar and a 3D-printed lid, into which the exhaust is piped.

[Blue HeelerParticipant @blueheeler]

G’day Richard, interesting re: the welders blanket.
I’m super careful about man made fibres, below.

You need to put up a video on Youtube, looked at your channel and it’s been a while. I’d like to see your steam condenser.

I’ve studied a way to make a blow down for the sight glass, but unfortunately there’s not a lot of clearance between the bottom of the sight glass and the firebox door.

 

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