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[rhavrane]

Bonjour David,
I fully agree with you, steam means torque and allow pitched propellers.
Besides this, I also like very much Simons's propellers, have a lot of them and made a video about them : https://youtu.be/EN0drJGsdDo    

[Mark T]

i swear by Propshop gear............beautifully made and perfectly ballanced too.

Me too - I do not think there is better out there

[DBS88]

I agree, the Propshop props are fabulous and have definatly improved the performance of other models that I have installed them on, Simon is very helpful.
Thank you for the advice received so far, decided to insulate the boiler. I first disassembled the boiler, then descaled and cleaned it. I had a thin insulating mat, so I cut it to measure and used PVA glue to hold it to the boiler. I chose to make the outer envelope that covers the insulation from a thin stainless steel sheet. I cut it with a guiletene and marked the location of the holes. I didn't have drills of the right size and it can be difficult to drill large holes in a thin sheet, so I used a small drill several times and a grinding wheel on my Dremel tool to open the holes. I made a mistake and damaged the finished side of the stainless steel, leaving deep scratches. I felt stupid and I was going to put the part in the scrap bin, however, I thought I would try to repair the damage. I started with a sheet of aluminum oxide 60 grit paper until the scratches are no longer visible. Then, used, papers 80, 160, 320, 600 and 1200 until I got a finish that I liked, not a mirror finish, but a smooth shine.

[DBS88]

As an experiment I used some high temperature paint on the ends of the boiler and on the boiler fittings. Once the paint had cured i placed the stainless steel wrapper around the boiler and secured it into position. I like the clean look so do not plan to use the traditional brass boiler bands. I then installed the boiler fittings.

[1967Brutus]

That's a mean looking boiler

[DBS88]

The paint is self priming, the first coat goes on, then after twenty minutes a second coat is applied. The paint flows nicely, it does not leave brush marks and has a high shine.

Whilst assembling the boiler I installed a new product from Dénes Designs. I have installed his simple low level warning device. Its a clever device that is not fooled by bubbles or rapid movement of the water, its designed not to give false alarms I have installed is because the steam plant is going in an enclosed tug, so the water level cannot be seen without removing the superstructure. The device will detect the low water level and will sound an audible alarm.Here is a link to a video of me testing the Dénes Design low water level warning system
https://youtu.be/L8vZdry2FCU?si=GVZdPir2rVtN_evz


Because I was concerned when I first ran the steam plant about flames escaping from the sides of the burner i have reduced the gas jet size down from a 10 to an 8. In addition I have created a stainless steel shield that is fitted between the burner and the sight glass. The aim is to stop any flames inpinging on the sight glass and also to protect the sensor .

[DBS88]

The engines were disassembled, cleaned, reassembled and painted along with other fittings. It was just as well because there were several loose bolts and the nut holding the seal for the piston rod was so loose that when the engine was rotated, the seal was sliding up and down about a 1/4 of an inch with the rod before hitting the nut and then returning to hit the underside of the cylinder. At first I thought the piston was broken, the movement was so strange. The piston and the cylinder bore were fine, the engines had hardly been run. The engines were well oiled as they were reassembled, they were then test run on air to rebid them in.

[DBS88]

A friend suggested adding a steam dryer to improve performance so a new chimney was created for the boiler. Instead of using 28mm pipe and fitting it inside the boiler flue exit I have used 35mm pipe fitted over the boiler flue exit. The external diameter of the pipe is 35mm and the internal diameter of the 35mm pipe is supposed to be 32mm. To make it fit snugly I made a ring from stainless steel sheet which took up the slack between the inside of the pipe and the outside of the boiler flue. I shaped the bottom of the pipe so that it was a good fit over the curve of the boiler casing. I then created a steam dryer and fitted that to the new chimney. Heres some photos which will give you a  better idea than my description.

[DBS88]

Having received some advice the chimney has been modified. The steam dryer enters the chimney on one side and exits on the opposite side. When I looked at it again, I realized it would be better if the exit pipe was at 90 degrees to the entry pipe. This provides a central straight pipe run to the engines. I then cut slots in the chimney as advised to make it easy to remove

[MikeMcP]

excuse my ignorance, but what does a steam drier do?
cheers
Mike

[SteamboatPhil]

A quick description is that it superheats the steam, which has removed any moisture and increases the steam expansion 

[Geoff]

In general its not too wise to overheat the steam as we typically use displacement oil lubricatord. A small part of the steam condenses, sinks to the bottom and forces the oil into the steam line thus lubricating the engines. Just check to see how it goes.


From the original picture I notice the gas tank was just touching the boiler, or very close to. This is wise because as the liquid gas evspourates it changes state and needs energy to do this which it takes from the surrounding air, thus coolong the gas tank which in turn reduces the gas pressure and flame size etc. On my two steam models I have the end of the gas tank touching the oil seperator/condenser which works well. At the end of a run the gas tank is hand warm thus maintaining gas pressure and flame size.


Just in case this impacts your layout.


Cheers


Geoff

[1967Brutus]

In general its not too wise to overheat the steam as we typically use displacement oil lubricatord. A small part of the steam condenses, sinks to the bottom and forces the oil into the steam line thus lubricating the engines. Just check to see how it goes.

Cheers


Geoff

That is a misconception... The oiler forms a "dead end" and any steam entering that oiler WILL condense. No way around that. The steam needing to be "wet" for a displacement lubricator to work is a misconception: Water in steam cannot condense any further, so the moisture in steam has no incentive to enter the oiler. Dry steam will creep to places where it can condense, and the dead end of the oiler IS such a place.

[DBS88]

Mike, I too was unsure what a steam dryer did and this was not helped because whilst the terms steam dryer and superheater have specific meanings, they are also as terms wrongly used interchangeably and also they are misunderstood. Following advice from this forum my understanding is for the majority of our small steam engines (not high performance racing steam engines) in model boats all we need to do is to raise the temperature of the steam a little to increase its energy and to reduce the amount that turns back to water. The subject of  steam, dry steam and superheated steam is vast with complex tables of temperature and pressure, so [size=78%]I was advised to watch this video by Kieth Appleton that gives a basic understanding. https://youtu.be/WzK0PJ6soxs?si=VDErNhlcfgvd_Gzl[/size]

[DBS88]

Having painted the engines and reassembled them the next task was to bolt them down to the base plate. I had purchased two stainless steel drive shafts with universal joints at each end. I realised that the base plate needed to be moved further towards the back of the boat, this meant the drive shafts were now too long. The board had to be moved further towards the back to allow the board to be slid towards the front of the boat when removing it from the boat. I therefore cut 2 cm from the hollow shaft only to find that the splined section was only on the end. I had to cut the hollow section off and then re attache the splined section, I used a smaller dia brass pipe and JB Weld epoxy glue to make the repair. I then cut down the splined part of the drive shaft. Since I had some stainless steel left from wrapping the boiler the decision was made to also cover the engine and boiler mounting board in stainless steel. Here are the engines and drive shafts being test fitted on the stainless steel covered board in the boat.

[1967Brutus]

Mike, I too was unsure what a steam dryer did and this was not helped because whilst the terms steam dryer and superheater have specific meanings, they are also as terms wrongly used interchangeably and also they are misunderstood. Following advice from this forum my understanding is for the majority of our small steam engines (not high performance racing steam engines) in model boats all we need to do is to raise the temperature of the steam a little to increase its energy and to reduce the amount that turns back to water. The subject of  steam, dry steam and superheated steam is vast with complex tables of temperature and pressure, so [size=78%]I was advised to watch this video by Kieth Appleton that gives a basic understanding. https://youtu.be/WzK0PJ6soxs?si=VDErNhlcfgvd_Gzl[/size]

That is correct... but the worst of it, is that wet steam simply increases the waterconsumption of the boiler: for a given power output X, waterconsumption increases with the saturation percentage, because only steam excerts labour, water doesn't.

So a steam dryer/superheater just reduces water consumption, and always is a good idea.

[DBS88]

Previously we had a brief discussion about props, their size and direction of rotation, I came across this diagram today that I found useful in describing the effects of prop rotation, so here it is, hopefully you too find it of interest.

[DBS88]

The PM Research engines are fitted with a rotary steam valve that selects both forwards and reverse as well as acting as the throttle to increase and decrease the rpm. When I purchased the boat, these valves were not connected and were not being used. The way it was set up bothcengines went forwards at the same speed, no reverse and no independent control of each engine.
To use the valves the way they are intended, I needed to install two servo's. For this I cut and folded some aluminium sheet that I had removed from the boat. I painted the brackets to match the other items. Originally I planned for the servos to be installed between the two engines so they were partially hidden by the engines. I soon realised that with the servos close to each other, if one engine engine was put in forwards and the other in reverse the potential existed for the servo arms to hit each other. To avoid this mistake the servos were positioned outside each engine.

[1967Brutus]

Previously we had a brief discussion about props, their size and direction of rotation, I came across this diagram today that I found useful in describing the effects of prop rotation, so here it is, hopefully you too find it of interest.

That effect is, as a matter of "duh" depending on the angle of installation of the propshaft, but more even by the shape of the hull in the stern area: Even if the shaft is perfectly horizontal, if the hull shape causes an upward vector on the water inflow towards the prop, that effect will also exist.

I have sailed on ships with an asymetric aftship, that intended to counteract this effect as much as possible. It was always a bit of a surrealistic sight entering the shaft tunnel to inspect the seals: the whole thing looked a bit like an M.C. Escher drawing...

[1967Brutus]

That effect is, as a matter of "duh" depending on the angle of installation of the propshaft, but more even by the shape of the hull in the stern area: Even if the shaft is perfectly horizontal, if the hull shape causes an upward vector on the water inflow towards the prop, that effect will also exist.

I have sailed on ships with an asymetric aftship, that intended to counteract this effect as much as possible. It was always a bit of a surrealistic sight entering the shaft tunnel to inspect the seals: the whole thing looked a bit like an M.C. Escher drawing...

Please keep in mind: Those engines will radiate a fair bit of heat, as well as expell quite a bit of humidity. I don't know if it is wise to install servos that close to the engines in an enclosed hull.

[DBS88]

Thank you for the advice re the servo location. The boiler was firmly bolted to the base board, then the next task was to install the gas line. This includes lengths of pipe to join the gas tank, a rc operated gas cut off valve, a Bix gas attenuator (it came with the boat) and the burner. I bent to shape and cut to length the pipe, silver soldered the fittings, cleaned the pipes and assembled the gas line and attenuator to the burner.

[1967Brutus]

That is some seriously neat&tidy work!

[rhavrane]

Bonjour David,
I have a RC gas valve like the one I see there and it leaks, so I did not install it, did you test yours ?
I really fear gas leaks and had a fire in one of my boats because of the RC gas valve itself ! https://youtu.be/DNTjVqbhezs

Besides this, great job indeed   

[DBS88]

Thank you for the kind words and support.


Raphael, sorry to hear that you had a problem with a gas leak and fire in one of your steam plants. Gas leaks in our models is always a risk, so great care is needed. I did test the gas line and the gas valves both with soapy water and also a lighter just to be sure, and no leaks were detected. 

[DBS88]

Next task was to cut, bend and silver solder the steam pipes from the steam dryer to the lubricator and then to the engines. The pipes were then cleaned and assembled. The whole steam plant was then placed in the hull to check it all fitted when the deck housing was added.