Identfying Bronze versus Brass

[DoubleWhisky]

Originally Posted by pbiJim

I'm not sure why the OP want's to identify a metal as brass or bronze. It may be more useful to determine if the item he has is suitable for the use he intends.

Fitting a through-hull may be???

[awpptdt]

Thanks to all, a lively conversation. I had allways used the cleaning polishing method, as was pointed out bronze will not shine like brass.

[sailorchic34]

Originally Posted by a64pilot

Sailorchic,
What do you do,or what was it you used to do for a living? I ask as your knowledge base is unusual

I'm a bit of a generalist. Was a professional mechanical/plumbing/fire protection engineer (self taught but with a PE) for building systems before being laid off for being too old at 55. Really anything in a pipe. I've designed large Central plants, plumbing, steam, pumps, chillers, boilers, Fire Protection, etc, etc. Schematic design through construction admin Worked up from draftswoman, back before PC's to senior project mangier, department head, etc. Boring stuff.

Designed building systems for bio tech, semi-conductor fabs, wineries,12+ large hotel casinos in Nevada. Pretty much read every manufactures catalog, building code, NFPA code, just for fun. I was a nerd back before nerds were cool.

Lets see, self taught in C/C++, that sailing thingy and 20+ other things, from sewing, to digital electronics, Diesel repair, photography, cycling (both types), etc. I also read a bit.

I once fixed a pinball machine that 5 expert pinball guys could not get working. It was the first time I saw the insides of a pinball machine. Took 10 minutes.

I'm not at all the typical girl next door.

[a64pilot]

what surprised me was your knowledge of Diesels, I figured from the rest that you were some sort of Engineer, but very few of them truly understand the actual mechanics of a thing

[leftbrainstuff]

There are many chemical compositions that may be called brass, bronze, stainless, etc.

The practical options for identifying material properties include metalurgical analysis, chemical analysis and destructive testing. None of these are particularly convenient to us boat owners.

Often it is easier and simpler to replace components with a known, certified and reputable product.

I have 3 engineering and materials degrees and am a qualified mechanic, airframe welder and toolmaker with about 70,000 hours of related experience. I can only reliably determine a material composition about 50% of the time without resorting to the above named test methods.

When in doubt change it out.

[sailorchic34]

Originally Posted by a64pilot

what surprised me was your knowledge of Diesels, I figured from the rest that you were some sort of Engineer, but very few of them truly understand the actual mechanics of a thing

Well Diesels are real similar to gas engines, outside the injectors and high pressure pump. I was my dad's tool getterer from about age 6 on. So know how to use tools, etc. My dad could fix just about anything too. So lots of the practical things came from him.

True some degreed engineers lack the hands on experience, Though partly because they lack the proper training and don't actually get on site anymore or talk to the contractors. So many get too specialized working on one sub branch in larger engineering firms.

Its really a corporate cultural problem. Much of the continuing education engineers are required do, is pretty pointless. I would ask young 20 something engineers after a lunch and learn sessions, what they really remembered an hour after the talk. Turns out not much. These were guys with masters and PE's too and sharp enough, in their narrow application specialty. Most never actually get to see how things get built or why they get built in the field. Crazy...

Me, I get bored pretty easy, so was always reading and studying how things work, moving to different companies, etc. Because after a while even billion dollar casino's and Bio-tech plants get a bit boring.

Ok thats the short intro to sailorchic 101. No more thread drift from me... today.

[Retired-Coastie]

Of course there is also sintered bronze for below the water line applications.

[pbiJim]

Originally Posted by awpptdt

I had allways used the cleaning polishing method, as was pointed out bronze will not shine like brass.

In my experience, the ability to shine after polish varies with the specific alloy. This is true of both brass & bronze.

If you have two pieces & you know that one is 360 brass, while the other is aluminum bronze, you can probably tell which is which by visual inspection, or by hitting them each with a file.

The visual inspection method is far less reliable if you just pick up a random piece from an unknown source & want to identify it, either before or after polishing.