The Steamboating Forum

Good Afternoon Everybody

On a wet afternoon in Cymru it is perhaps a good time to be thinking about water.

What I am seeking is a small and light hand pump for the monotube boiler that I am building. The two coils are a bit shorter than 25ft (7.62m) in length. The first is 3/16" OD pipe with an ID of 3.1mm while the second is 1/4" OD pipe with an ID of 4.8mm. If I have done the 'sums' corectly that gives a total water content of 0.138 litres.

What would be nice would be a smallish pump with a decent handle rather than a Model engineering one which might have the righ sort of output but are too tiny.

So, suggestions welcome.

Pete

Hi Pete,

I would think one of the Pearl engine co, or Elliott Bay offerings would do. Might have to sleeve down the bore (if cored into the casting) for such a small capacity.

Conversely, one could make their own pump with regular plumbing pieces and a little fabrication. The feed pumps on 'Persistance' and 'George H Sandin' are made that way. Only difference would be adding a bracket for the hand lever trunion.

Hi Wesley

Thanks for your suggestions. I have had a look at Pearl, but since the business is up for sale there is no separate information about a hand pump. Elliot Bay seem to be offering the same pump as the SBA albeit and a much greater price. I must admit to having got very cold feet at the sight of the SBA price, but it looks like a design that one could re-draw for fabrication at a reduced scale. The elliot bay photo is a good one to show how it all fits together. That might well be my solution.

The ony trouble is that I have to make a whistle valve, then the whistle before the hand pump rises to the top of the list.

Hope that things are good with you and that you have managed to get some boating done this season.

Regards

Pete

If you went with one of the SBA offerings you'd have room to bore (grow) for when you build a bigger monotube haha

Hope things are going well your side of the pond. Any luck on tracking down the copyright holder for that other information I sent a while back? Might be covered under free use perhaps?

My hand pump is very crude looking, but very cheap and easy. It's literally an industrial pneumatic cylinder, and a couple pneumatic check valves. Most industrial air cylinders are good to 150-200psi, and are aluminum and stainless steel. They can be had for a pittance on Amazon or wherever. Just pay attention to the thread size on the smaller ones.

Hi Rolph

Many thanks for posting the suggestion and the photo. What an excellent idea! I notice that the cylinders are widely available on eBay on this side of the world so there is every chance I will copy you. I just need the time to get a drawing done...

Regards

Pete

Great use of existing stuff. I'm impressed!

I've had very good service out of those in-line check valves. I didn't know that they were intended for pneumatic service.

Mike

Yes, the cylinder is off the shelf (chinese) pneumatic cylinder from amazon. I work with these cylinders every day, they usually have viton o-rings and either stainless steel or chromed piston rods. The only thing the look out for is that the ports are often BSP instead of NPT.

The steel parts are literally from an old bed frame, no designs, all eyeballed, angle grinder and cheap welder.

I wish I knew where I got those check valves, because they are really nice. As long as you're not working with hot water or steam, many off the shelf check valves will work. Sometimes you have to watch for the cracking pressure on the "suck side" of a pump. For steam rated check valves, I bought some all bronze gravity swing check valves from Menards. They worked great in my WIP lamont boiler. The only problem is they don't come in anything smaller than 1/2" npt.

take a look at these castings - I made one for Befur (with o-rings not stuffing box).
https://www.steamboatassociation.co.uk/ ... eamboaters

Hi Malcolm and Friends

Yes, the SBAS castings will make a magnificent pump, but a bit large for my canoe project and, as a tight fisted Welshman, far too expensive for this project.

I am at the moment building two versions using these cylinders since I accidentally bought a pair. If anybody is interested in my designs I could post them up here. One is a classic vertcal type based on the pump that I had in Frances Ann, while the other is a development (rip off?) of the design in Rolph's picture.

Regards

Pete