Re: bronze assay
At 08:51 PM 4/26/02 EDT, you wrote: >Harry, >What is the composition of SAE 660? Walt, It's new designation is C93200 but it's still commonly listed as 660. Every mfgs's metal is going to vary slightly but the typical composition of 660 is Cu - 81-85%, Tin - 6-8%, Lead - 6-8%, Zinc - 2-3% Although it's got both lead and zinc in it it's been used for years for boiler bushings and it does very well. The zinc and lead content is so low that the lead doesn't affect silver soldering nor does it leach. Compare this to C544 (now C5400) , the proverbial "Phosphor Bronze" that's specified for bushings: Iron - 0.1% max, Lead - 3.5-4.5%, Phos - 0.01-0.5%, Tin - 3.5-4.5%, Zinc - 1.5-4.5%, Cu - Balance. Not a great deal of difference, but enough I suppose. Regards, Harry
Re: bronze assay
Hi, Red Brass is usually Cu, Sn, Pb & Zn, Semi-red brasses have a little more Zn. Yellow brasses have from 58 to 72% Cu and as high as 40% Zn. Many of the manganese and silicon bronzes contain Zn, up to 34%. There are over 20 pages of Cu alloys listed in Machinery's Handbook, along with all the screw pitch dimensions, etc, etc, etc. If you are going to be building or modifying live steamers, you should probably buy a copy. The price used to be around $60.00 for a new edition. However, the older editions still have basically the same information, just don't have the new fangled fasteners, etc. in them. Wish I could say that I'd profit from your purchase, but sadly I'll remain a "po-folk." Keep your steam up! Walt
Re: bronze assay
Hi, You could try the do some de-zincification using common swimming pool acid -- HCl or often called Muriatic acid. Nitric acid is very dangerous to use, it is a 'skin eater' acid. Muriatic does not eat your flesh, but the fumes can be hazardous to mucous membranes, eyes, etc. Put some small pieces of the questionable bronze in the acid and let it stand for a few hours. If there is Zn in it will "fizz" and after a while the bronze will be more the color of Copper. We use gallons of HCl to clean brass after it has been stripped with aircraft paint stripper to remove lacquer, varnish, poly, etc. NEVER put a piece that is 'brass plated' in the HCl bath. 98.753% of plated lamps, etc are diecast zinc with a very thin copper strike before the thin brass strike(plate). In just a minute or two, the Zn will be gone! As a grad student I spent some time working with radioactive isotopes to measure nutrient uptake and translocation in plants. We were required to wash our hands before leaving the lab with conc. HCl. Stings like H... in a cut or scratch, but otherwise it's not fatal. I'm sure there are more humane methods now, but way back there in the 50's we wuz on the upside of the lernin curve, you know! Keep your steam up! Walt (FORMER soil chemist/physicist)
Re: bronze assay
Harry, What is the composition of SAE 660? On pages 2140 and 2141 of Machinery Handbook 24 are listed 28 Bearing and Bushing Alloys. There are no numbers in the 2xx, 3xx, 5xx or 6xx series for bushing bronze. Maybe I need to get a new handbook. 24th Edition was in 1992. I must admit that there are still more than a few pages out of the 2543 that I have not read! Keep your steam up! Walt
Re: bronze assay
At 07:54 AM 4/26/02 -0700, you wrote: >Hi group. I have an ingot of what I was told was bronze, >Anybody know how to tell if there is zinc in the alloy? >royce Royce, I'm in pretty much the same situation as I have lots of scraps of this and chunks of that. Since it's from an art caster the probability is that it's bronze, but no certainty. Brass has a distinctly yellowish color and bronze is more golden or red, but then "red brass" looks so much like a low bronze it's very difficult to tell the two apart and I have a large quantity of certified C510 phosphor bronze which looks for all the world like yellow brass. Go figure. Brass tends to make very (very) small chips, bronze comes of in chips also but substantially larger. If you look at Cu alloy charts you'll find that almost all copper alloys listed as bronze have fractional % traces if zinc, even the phosphor bronzes preferred for bushings and such. All things considered I agree with Paul, go to a local bearing house and get a stick of 5/8" SAE660 bearing bronze which should cost less than $10 and that way you'll know what it is and have it for the next project. Regards, Harry
Re: bronze assay
On Fri, 26 Apr 2002, Royce Woodbury wrote: > Anybody know how to tell if there is zinc in the alloy ? I was > going to put some nitric acid on it to see if it "foams". That any indication > ? TIA > Go to a local metal supplier(or even one of those really expensive mail-order outfits) and order bronze barstock. It's the only real way to be completely sure, and it's not worth the effort to test an unknown sample when you can buy a known alloy for much less money. --- Paul Anderson geeky1!paul "Nature has been kinder to us than we had any right to expect. --- Freeman Dyson
bronze assay
Hi group. I have an ingot of what I was told was bronze, from which I have been making parts for my locomotives (axle boxes, cylinders, etc). But as I am now going to need to make some boiler bushings, I want to make SURE that this "bronze" has no zinc in it. (I got it indirectly from a person who does bronze (art) casting) Anybody know how to tell if there is zinc in the alloy ? I was going to put some nitric acid on it to see if it "foams". That any indication ? TIA royce in SB
