Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: Kmot on November 19, 2010, 05:01:34 am

Title: Boiler material question
Post by: Kmot on November 19, 2010, 05:01:34 am

For anyone who knows:

When constructing a copper boiler, is it recommended to use the same thickness material for the end caps as the thickness of the boiler body?

Or is it a non critical issue?

I have 3" diameter Type L copper pipe which is .090" nominal thickness. I can get copper sheet in 14 gauge at .095" or 16 gauge at .065". The thicker the copper the harder to work it into some domed caps. I was hoping I could just use the 16 gauge for the end caps.

Thanks!

Title: Re: Boiler material question
Post by: sunworksco on November 19, 2010, 05:24:22 am

As a person working in boilers for years, I myself would use the same thickness bulkheads as the copper tube.
You can always machine some mandrels and heat the thicker copper sheet, then compress the mandrels tight in a hydraulic press, made from an inexpensive jack.
Giovanni

Title: Re: Boiler material question
Post by: Kmot on November 19, 2010, 06:36:57 am

Thanks for the advice John. :)

Title: Re: Boiler material question
Post by: gondolier88 on November 19, 2010, 07:32:22 am

If you can't find the same thickness then dish the ends outwards which is the strongest form of boiler end caps, and stay it with a decent size (at least 5/32") bronze stay.

Greg

Title: Re: Boiler material question
Post by: Circlip on November 19, 2010, 12:18:20 pm

Don't go searching too hard Kmot, you've allready got some material the same thickness as the tube? It's called "The Tube" (Slit and flatten a piece). On the "Other" forum in the books section, there's a freebie download of Hariss's Bible, that's the one everyone should be following for the pressure calcs.

  Regards  Ian.

  Oooooooooooops, nearly forgot, ANNEAL regularly, saves tears (The crying ones)

Title: Re: Boiler material question
Post by: gamma on November 19, 2010, 04:49:34 pm

Hi kmot...nice to see you here too   :-))

Sergio

Title: Re: Boiler material question
Post by: Kmot on November 19, 2010, 05:14:26 pm

Thank you all,  for the replies. Re: cutting off a piece of tube and slitting, etc. Nope, sorry Ian, that would end up making a very short boiler!  {-)

Anyway, per most advice I have placed an order for a piece of .093" sheet. (I was wrong about it being .095).

I have Stan Bray's book and I intended to make a domed hardwood form, and pound the annealed piece of sheet over it. Re-annealing as I work it. However, I very much like the idea of sunworksco about making a mandrel and using a hydraulic bottle jack. I will have to think about that some more.

Hi Sergio!  ok2