Boilers - just picked up an old one.

[raynerd]

Hi Guys

All the models I have made have been run off a compressor. I recently aquired an old boiler as shown below. I understand that boilers work under very high pressure and can be dangerous but I would like to get this one up and running.

There is obviously the valve that I will need to replace and check but there is also another hole at the top with no cap or cover, I guess this is missing something? There is no threading or anything on this hole.



Any more info would be really helpful. I`ve done a few searches online but nothing really explaining how it runs and certainly not specific to my little boiler. Hope someone can help.

Chris

[Darren]

Shelve it....

I wouldn't risk it until you have more knowledge and testing facilities, boilers are far more dangerous than you might think.....

[Brass_Machine]

I gotta agree with Darren on this one. Boilers, even small ones, can get you (or anyone else near) seriously hurt or even killed. Don't know the history of that one? Shelve it. Not worth it.   

Eric

[bogstandard]

Forget it, just not worth it.

Just been shown again over on HMEM, now here.

[sbwhart]

Chris

That one looks like its held together with bird droppings, the best place for it is the scrap bin don't risk messing with it.

Stew

[raynerd]

Fair play, understood.

It came with a little wobbler that is in need of attention so it was still worth the few quid I paid for it.

Chris

[Brass_Machine]

Fair play, understood.

It came with a little wobbler that is in need of attention so it was still worth the few quid I paid for it.

Chris

Oohh rebuild of a wobbler. I see a project log coming 

That will be nice. Trash or shelve the boiler.

Eric

[Darren]

Chris,

To expand, my concerns would be, quality of the original boiler and what it's made from. Quality of the solder joints, might have been fine when new, but what of now.

And lastly, general corrosion. You don't know what's been eaten away inside?


I'm guessing that to test you would need a high pressure compressor and gauges to suit. Oh and some sort of safety cage. I doubt our workshop compressors generate high enough pressures? I don't really know, but that's what I would want to do, test it well and above any working pressures before contemplating using it.

I understand boiling water generates some very high pressures when sealed in a container. It takes little extra heat to send it climbing at a frightening rate.

[bogstandard]

Darren,

You should never pressure test anything with air. It should always be done hydraulically.
If a boiler bursts when pressure testing, with air, it becomes hundreds of bits of shrapnel. With liquid, a couple of drops and all the pressure is gone.

John

[Darren]

Ah yes, obvious now you mention it John....air makes a very good propellant....

Good job I can't see myself wanting to carry out such a test init....

[sbwhart]

Chris,

To expand, my concerns would be, quality of the original boiler and what it's made from. Quality of the solder joints, might have been fine when new, but what of now.

And lastly, general corrosion. You don't know what's been eaten away inside?

Chris just to expand a bit on Darrens link and without getting too technical Brass does strange things with age, it goes brittle, particularly in the presence of certain chemicals and stresses.

Stew

[John Hill]

I would not get too paranoid about boilers but they are something that must, repeat must, be respected.  There are recognised ways of testing and asessing the safety of boilers and a local steam model club may be qualified to do this.

[NickG]

I'm not sure about the rules on "Toy" (and I use the term loosely as they are far from toys) boilers of that size e.g. Mamods etc. I don't think they require testing, but in any case, I agree with everybody here - unfortunately, that is one for the scrap bin as you don't know any details about it.

You'd be better off researching the subject of boiler making and making one from scratch. I'm sure there is a book on model boiler making if you're interested I will try to find out. I think I may have seen that down at the club as well but don't hold me to it.

It's not an easy art to master, you'll probably end up making scrap and spending quite a bit on equipment if you don't already have it but I bet it's satisfying once you get there.

Rich (Firebird) has done a couple of interesting boiler projects on HMEM, with a steep learning curve. Have a look at those to give yourself an idea what's involved.

http://www.homemodelenginemachinist.com/index.php?topic=2092.0
http://www.homemodelenginemachinist.com/index.php?topic=4779.msg62263#msg62263

Nick