I don't know if anybody has considered this, but it might be possible to build radio controllable pop-pop boats by using refillable butane lighters as heaters instead of candles or burners.
Some of the companies that manufacture butane lighters include:
Colibri at http://tinyurl.com/m3kb4
Prometheus at http://tinyurl.com/klcgn
Solo at http://tinyurl.com/plpx5
and Vector at http://tinyurl.com/rp5md
The best kind of lighter for this purpose is probably one that’s called a  â€œutility” or “candle” lighter. A candle lighter suitable for control by using a servo instead of a “thumb” is  shown at http://tinyurl.com/lvqex .
There are several configurations for pop-pop engines. Hobbies of Dereham sells an integrated model with a smokestack shown at and propulsion tubes that would extend through the bottom of a hull as indicated in a view at http://tinyurl.com/j2hxm .
The Pop-pop Pages at http://tinyurl.com/p54qx show mostly little tin boats with two propulsion tubes that extend through the stern of a hull below the water line.
Would anybody like to do a small scratch-built model of HMS Warrior? Maybe sail management could be provided by using a servo to rotate masts with rigidly attached yardarms.

Hello, I just discovered this topic. Seems there isn't much interest in pop-pop boats?
I am planning to build one, with a wooden hull and the water-pulse-jet-engine made of brass sheet and pipe, r/c.

I'm not sure it's a lack of interest, probably a lack of knowledge - I for one, don't really know how these things work, and the only ones I've ever seen have been small tinplate toys.

Regards
Eddy

The energy output from pop-pops is very small, hence most models are tiny in comparison to the engine size. Really they are only suitable for indoor use. An old friend in Sunderland built a 32 inch model which required FIVE of the pop-pop engines produced by USE engines in England (as mentioned in first article and still available). Even so, the model only just crawled along and couldnt penetrate the slightest breeze! Also, the smallest speck of debris would block up the intake pipe. The addition of radio would have killed it dead in the water!!. One for the experimenter or a modeler sick of life!!.Sorry to be a killjoy, but I have played with them MANY years ago. Regards, Walter.

As Walter says they are very low power. I had our Scout Troop build some a few years back. If there was no wind they would go at a slow walk. I did run one with RC rudder, but it was very slow.
Regard,
Gerald.

I'm glad to hear about your experiences. I have a toy pop-pop boat It runs pretty well actually. Certainly not fast, but steady. So I thought I could build a better one. Should be fun to do. I am planning an alcohol fired engine, perhaps with an adjustable flame to make it run slow or even slower :-)

By the way, I have tried accessing the Yahoogroup from the first posting and while it worked this morning, now Yahoo says it doesn't exist any more? That's very weird!

I remember seeing some articles in either Model Boats or Marine Modelling mags, I think some time mid 80's, where a chap had four pencil blow torches running his rather large pop-pop models. As far as I remember, he had some good results with them, but his tubing system was very professionally done, with all the engines having the tubes interlaced with each other to keep them very compact.

John

Hi John,
I think it was in Model Boats, I think in some he even had check valves fitted I must look and see if I can find the issues, I know I have some of them around. I have built the ones using 1/8 to 3/8 copper tube. I have tried the pan type but never had much success with them.
Regards,
Gerald

I'd really liek to have a look at those articles. Do you happen to have them?

Gerald, what were the check valves for?

Gerald,

It is many years ago since I made any of these engines, and like yourself, went for the coiled pipe, and they could be bent up in a matter of minutes.

As far as I can remember, one pipe was slightly longer than the other, this gave the imbalance that meant one end of the tube always worked as exhaust and the other as inlet.

Of course, after the initial charge of water, we are talking about a basic, self priming flash boiler. That sounds a bit more technical than pop-pop.

John

There have been various articles and postings on the net about ways to build improved versions of Pop Pop engines. The one mentioned with check valves used flaps to try and make sure all the power went out the exhaust side. I have a file of the articles and will look it out when I am home again and post some links or the dates of the magazine articles. Cheers, Ian.

There must a a great deal of similarity between a pop-pop boat engine and a Humphrey pump, but the latter is far more sophisticated, and used valves to control the inlet and exhaust cycles.  Try finding some online references (they exist), and see if the design could be adapted to model-boat use.  Mechanically, the pumps were elegant: the water pipe was the combustion chamber, eliminating a lot of mechanism, and enhancing efficiency.  Somewhere in paddleducks should be a report of my visit to the one preserved in operating order at Cobdogla (SA), at a museum which also  has a steam railway and PS Roy (awaiting restoration).

Regards,
Roderick B Smith
Rail News Victoria Editor

Hi, I'd appreciate any links to articles, pictures, diagrams etc.

However, I notice some of you say that pop-pop engines have an "exhaust side" and an "intake side". In my experience, pop-pop engines (both coil models, and pan models) work with both pipes in parallel states: I mean they both exhaust water at the same time, and then suck in water at the same time, in rapid succession.

They will work with only one tube. I have seen one run with a coil sealed at the top and the other end in the water.
I tried on one of mine by using a wood plug in one of the tubes, it would run, but slower and would lose its prime more often.
Regards,
Gerald

Quote from: steamboatmodel on December 29, 2008, 09:33:39 AM
They will work with only one tube. I have seen one run with a coil sealed at the top and the other end in the water.
I tried on one of mine by using a wood plug in one of the tubes, it would run, but slower and would lose its prime more often.
Regards,
Gerald

I agree, but that's a different situation. I was referring to the normal set-up (2 open ends to the tube).