For what it's worth, I've confronted the brass/bronze issue too. I had a large ingot of "bronze" used by a local artisan who did bronze casting. I acquired it before I got very far into building live steam and thought that it would be a great source of bronze. When it came time to make bushings for my boiler, I was concerned about it's zinc content. So I took a piece and chucked it up in the lathe. After truing, I took a heavy cut in order to obtain a thin but continuous piece of swarf. I then put this in an air tight container with a few drops of muriatic acid (HCl) and waited. After some amount of time (days or weeks, I can't remember), the swarf would just crumble in your hand. So I assumed that this material contained too much zinc to use as boiler bushings. In addition, I tried it for the cylinders of my Philly. I can't remeber the way I discovered it but it turns out that the material had an abrasive effect on orings. I then concluded that it contained silica (sand) and was unsuitable for any sliding surface use. I think that I used it to turn the domes and stack. But it's not any good for what I had hoped to use it for. So now I buy known alloy metals for critical parts.
royce in SB J.D. Toumanian wrote: >>>I wonder how many of us have >>>had one of our unidentified brass bits disintegrate or whatever over >>>the last, say 25 years? I certainly have had no problems and I don't >>>know anybody who has. >>> >>> > > >I had a brass safety valve crumble on a scratch built LBSC "Dot" when I tried >to use a spanner to remove it. The zinc was gone and the metal that was left >looked like sintered bronze... it was porous. No telling exactly how old it >was, but to me it was "NOT OLD ENOUGH"! Whenever I scratch build boiler >fittings these days I use bronze, although I too have been using surplus ends >from a local scrap dealer. I am starting a 1.6" scale 2-8-2, and I will >purchase new material of a known composition for it's fittings. > >I've also had two toy steam engine boilers fail by developing leaks... One was >a Mamod tractor and the other was a Wilesco stationary engine. Both had very >high mileage, so to speak, because they were toys from my childhood and I ran >them thousands of times. Both failed in the middle of the bottom of the >boiler barrel, the hottest part, by developing pinhole leaks that eventually >got bad enough that they put the fire out. Because they were hidden, I didn't >notice the leaks until they reached that stage. > >The Mamod got scrapped when I was 12 years old... I removed the engine and all >other parts and threw the defective boiler away. I wish I still had it. The >Wilesco boiler I removed and mailed to Wilesco as defective, and even though >it was probably decades out of warranty, they sent me a replacement and that >engine is still "in service" on a shelf in my library today. Good customer >relations on their part if you ask me. > >Regards, >Jon > > > _______________________________________________ SSLiveSteam mailing list Send messages: [email protected] Cancel subscription: http://postfix.45mm.com/mailman/listinfo/sslivesteam Rules: http://www.45mm.com/sslivesteam_guide.html
