Since Lionel was mentioned, and as an example of the randomness of this, I had a C&NW NW-2 Cow and Calf set.? Not sure the year.? 1990's?? I decided to sell it and was testing it first.? One of the "coupler armatures" (a sort of long flat part) crumbled.? The others were absolutely perfect.? Annoying.? Also, Lionel made these with shells molded yellow to skip painting them.? The headlights glowed through shells so much that Lionel finally capitulated to complaints and provided buyers with replacement shells that were painted.
This is not the only area where items from China are sometimes sketchy, and it might seem we are going backwards.? A well-known issue among model railroaders collecting older brass engines is the deteriorating used to pack some of them as it damages any paint it is in contact with and even damages bare brass.? But there have been an array of plastic and "rubber" issues over the years, usually with problems of the plasticizers used (another big topic).? I have noticed a big uptick in such problems where some bubble wrap can rather quickly contaminate surfaces it is in contact with rather (makes a polka dot pattern of surface damage) due to a plasticizer that is leaching out that is aggressive somehow.? And rubberized material getting very sticky to the touch after less than a year.? Such things are not new as I have repaired brass locomotives where the "rubber" coupling has turned to goo, and in one case even dripped, but oh so slowly over a half century of being stored.
If you want to cast your own Zamak, you can buy new alloy from a reputable supplier, and it should be fine.
In the one-inch scale live steam model railroad world, there was a fellow named Nelson Gray who made wonderful parts for trucks and more out of zinc alloys, probably one of the Zamac alloys.? He even made his own diecasting machines, as I recall.? I have never seen or heard of one his parts failing so he was probably careful where he obtained the alloys.? Curiously, he also made parts for the tiny Z scale and Nn3 model railroading.
It really pays to be careful about your sources.? A fairly recent story came out where both Boeing and Airbus seem to have gotten some "counterfeit titanium" with counterfeit paperwork, apparently, and "small holes were discovered in the material, apparently from corrosion,"? Still being investigated, I think.
I don't know the average age of Unimat users, but if it is anything like model railroaders, we probably won't have to worry about seeing the results of using even a bad alloy if we cast something today.
Charles E. "Chuck" Kinzer
On Friday, July 12, 2024 at 07:51:35 AM PDT, Edward Samsen via groups.io <edoptician@...> wrote:
I know about the Best Friend of Charleston issue...Lionel made in China.? I would suggest that Bowser or another manufacturer make replacement frames from either BRASS or PEWTER...Bowser is familiar with making "Lost Wax" castings as they made CalScale castings for years and also pewter as they have remade the old Selley line of lead castings now in Pewter....should last forever.? K-Line another O tinplate manufacturer had trucks fail because of Zinc Pest in relatively new castings less than 30 years old? again guess where they were made?? quality control alloy contamination etc? Lionel in the late 30s had trouble with first run of the Scale? and Semi-Scale Hudsons? ties on the T-Rail track and a few other items due to zinc pest? They worked out their difficulties I have several die cast locos from the 1940 era? all good