Charles

It might also be a good idea, to keep a photographic record of the
boilers construction as this is also important, and to cover all, try
and get certificates for the material, or at least the grade number.
It may seem over the top, but better safe than sorry after all that
hard work.

Ian


--- In halfinchlivesteamforum@..., "Charles Mortimer"
<mortimer@...> wrote:
>
> hallo Simon
> yes theirs that to ,,which has to be taken in consideration , its
always best to err on the thicker size ,,,by getting other peoples
thoughts every-one will have a good idea of what is acceptable... i
myself want to be in the British guide lines ....i will be using 2mm
and three mil thickness,,, over engineered maybe at least ..i can
prove to the boiler inspector it will be on the right side also it
will give me more weight (tractiv effort) some lighter engines suffer
problems like ,,,that even the frames will be1/8 steel ,,, in other
words built like a brick dunny,,,i know the tubing that you are
referring to its plentiful here and can be bought by the meter
thanks Simon i am getting a good picture built here of what's
acceptable
> Charles in oz
>
> ----- Original Message -----
> From: Simon Wass
> To: halfinchlivesteamforum@...
> Sent: Wednesday, May 14, 2008 7:57 AM
> Subject: Re: [Half inch live steam forum] Re: question on boiler
material
>
>
> I'd always thought the reason for thicker plates was the
unsupported areas
> you tend to get with the back, throat & smokebox tubeplates. A
backplate can
> have big (ish) areas where there are no stays, the throatplate
needs to be
> thick if using the Curly method of a butted join (I use a full
flanged
> throatplate and think I'd be ok with 16swg but still use 13!).
I'm sure what
> I've built in this sort of model size (Tich, Invicta & Scotsman)
all use
> 16swg for all inner firebox plates? Not got a model or their
drawings to
> hand though! For my tubes, I use 10mm microbore household
plumbers pipe, not
> sure of its swg? A 10m roll is very cheap (for copper!).
>
> ----- Original Message -----
> From: "John Baguley" <baggo@...>
> To: <halfinchlivesteamforum@...>
> Sent: Monday, May 12, 2008 8:54 AM
> Subject: [Half inch live steam forum] Re: question on boiler
material
>
> > Hi Charles,
> >
> > I am not sure if there is actually a spec laid down over here
for
> > metal thickness versus boiler size. However, the 'standard'
seems to be :
> >
> > barrel, wrappers, and crown stays - 16swg (1.6mm)
> > Smokebox tubeplate, throat plate, backhead, firebox plates -
13swg (2.5mm)
> > Tubes - 18swg or 20swg (0.9/1.2mm)
> >
> > For a small boiler you can get away with 16swg for the throat
plate,
> > firebox tubeplate and firebox door plate. Makes flanging the
plates
> > much easier as well. I've read that the only reason for using
13swg
> > for the backhead was that LBSC used to thread his fittings
straight
> > into the copper without using bushes and the thicker metal
gives more
> > thread. I would not recommend that practice nowadays though!
> >
> > John
>
>
>
>
>
> [Non-text portions of this message have been removed]
>