Annealing 22swg brass sheet- is it neccecary ?

[Chris machinParticipant @chrismachin]

Hi , I’m making the ‘Polly’ steam engine out of Tubal Cains book ‘Building simple steam engines’. The boiler require a piece of 22swg brass sheet to be formed into a small cylinder. The brass sheet arrived today from the supplier but it appesrs to resist being formed into a ‘tight’ cylinder

I think if i try it it will ‘kink’ rather than form a neat cylinder !

 

1.Does the sheet need annealling all over and will it make it easier to form ?

 

2. Will the annealing damage the surface / shine on the brass or will it just polish back to its original finish ?

 

3. If it does need annealing do i just heat it all over to dull red then quench in water

 

Any help appreciated.

Thanks

Chris.

[Chris machinParticipant @chrismachin]

[JasonBModerator @jasonb]

What grade of brass is it?

 

If you have been sent one of the harder brasses such as CZ120 it will be a job to bend but a softer brass like CZ108 will form into a cylinder OK, the flanged ends are still liekly to need a couple of annealings.

 

It will go a dirty brown/black colour, dipping in the acid that I mentioned in your other post will get it clean enough again for soldering, dip it in teh pickle again after soldering and that will leave a dull brass so you will have to get a buffing wheel on it to bring back the shine.

 

I prefer to heat to cherry red then allow to cool naturally

 

J

[Chris machinParticipant @chrismachin]

Hi , Many thanks for your help – its appreciated

The brass is CZ108 according to the supplier (ABS Metals).

So i heat the sheet to dull red all over , let it cool naturally and then it will form easier – is that correct ?

Thanks again.

[David LittlewoodParticipant @davidlittlewood51847]

Chris,

 

Be aware that fully annealed brass can be very soft, handle with care to avoid unsightly dents. Also, copper and most of its alloys will work harden – if you need to bend it far, you will feel its resistance increase, and that means it needs annealing again. Lastly, those alloys frequently show age hardening, that is if you anneal them and then forget about them for a while (a few days or maybe weeks) it goes back to its hard state. I can’t say for sure that the grade of brass you have will show exactly these characteristics, just be on the lookout.

 

On etched brass kits I find a scrub with Viakal is good to restore a clean finish.

 

David

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