Bronze

[firebird]

Hi

At the Elvaston Castle steam rally today a guy was selling lengths of bronze, not phospher bronze just bronze. Whats the difference apart from the obvious that one has phospher in it and one doesn't. I didn't buy any in the end as I wasn't sure if it could be used as boiler fittings etc. Can anyone enlighten me

cheers

Rich

 

[rake60]

Online Metals has come very good product guides that
explain the different alloys for materials.

This may be of help: The OnlineMetals Guide to Bronze

Rick

 

[Stan]

Bronze is an alloy and unless you have some way to identify the alloy, you have no idea what you got. Many years ago a bronze caster told me simply that there is no such a thing as "bronze". His business was making bronze material for statues, dedication plates (where politicians put their names), builders hardware and decorative material and artwork. Everything he made was a different alloy to meets the needs of the end user.

I wouldn't want to use any of his material for machining unless it was for something like candlesticks.

 

[rake60]

Interesting thoughts Stan.

Bronze in one of the oldest man made alloys.
At first it was a simple recipe of copper and tin.
Soon after the metalsmiths of the age discovered that
adding arsenic made it a stronger metal. (arsenical bronze).
Since then the spectrum of alloys that are called bronze have
been grown to a scale where identifying them after the label
has been removed is practically impossible.

Replace the tin in that copper alloy with zinc and you have brass
and a whole new set of indistinguishable metals to deal with.

Rick

 

[firebird]

Hi

Just looked at the online metals guide. It gets confusing doesn't it. Is there a simple yes or no answer to the question can any sort of bronze be used or am I hoping too much.

Cheers

Rich

 

[Stan]

A few months ago I mentioned that I had got a deal on some magnesium bronze at the scrap dealer. In my research, I found that a common use was for valve stems and this made sense because the piece came from a machine shop that does oilfield repairs.

Today I had occasion to use some. I put a 1 5/8" round bar in the 4x6 bandsaw and went about doing other things. When I went to get my peice, the cut had only progressed less than .125". Ah, cheap carbon blade, replaced with new 8/12 bimetal blade and turned bar to start new cut. New blade cut even less than cheap carbon blade.

I put the bar in the abrasive chopsaw with a ferrous blade and it cut well with a clean cut and obviously, no sparks and no damage to blade.

I put the 3" piece in the lathe and to face the ends and clean the surface and it cut beautifully, with a mirror finish. I put it in the mill with a 3/4" end mill to make a flat side and the cutter was dull before I went down 3/16". I finished the flat with a carbide end mill.

Back in the lathe to drill and tap a 5/8" x 18 hole the full length.Drilled OK with 1/4" pilot drill and then 9/16" drill. I tried to run a .5630" reamer and it was dull before I was halfway through. I am still working with a tap and I am in about 2" and I can only get a couple of threads before it squeals. I should have single pointed the thread.

Incidentally, when the D shape piece was turning, the surface finish is so high that the reflected light coming off the surface was a distracting flash.

Rich: Does this answer your question?

 

[ianjkirby]

Hi Rich,
I would like to suggest that you do not use brass for boiler fittings. The zinc in brass will slowly leach out, leaving a fine honey-comb structure which will eventually crumble when its strength gets too low for the job.
Regards, Ian Kirby.
Wollongong NSW Australia
javascript:void(0);

 

[Loose nut]

Hi Rich,
I would like to suggest that you do not use brass for boiler fittings. The zinc in brass will slowly leach out, leaving a fine honey-comb structure which will eventually crumble when its strength gets too low for the job.
Regards, Ian Kirby.
Wollongong NSW Australia
javascript:void(0);

Ian's right, brass fittings on boilers have been known to cause failures of boilers under steam, not a desirable situation.

 

[tmuir]

Ian's right, brass fittings on boilers have been known to cause failures of boilers under steam, not a desirable situation.

Correct me if I'm wrong but I've heard that if you use brass fitting on a copper boiler the fittings will degrade quicker than if the same brass fitting were fitted to a brass boiler. I'm guessing as the whole boiler has the zinc leached out of it meaning only a very small part from the fittings whilst a copper boiler has no zinc so more can be taken from the fittings.

 

[firebird]

Hi

I'm only using PB for all the fittings on my small boiler, I am aware that brass should not be used. I just wondered if it was ok to use pure bronze.

Cheers

Rich