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Re: Metal fatigue or Zinc Pest?
¿ªÔÆÌåÓýPat Doesn¡¯t conformal coating the PC board prevent the whisker growth? John ? From: [email protected] [mailto:[email protected]] On Behalf Of pat goodyear
Sent: July 12, 2024 9:59 AM To: Dave Seiter; [email protected] Subject: Re: [Unimat] Metal fatigue or Zinc Pest? ? A little off subject? |
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Re: Metal fatigue or Zinc Pest?
A little off subject?
So it is very interesting how lead can be good and bad additions to alloys.? ?My primary field is electronics and back in the 40's engineers found out that if you add lead to tin in solder it reduced the melting point, and if the ratio was 37:63 there was the perfect match and solid-liquid occurred at the same temperature (eutectic point).? ?Since my specialty was legacy electronics, I was the one to chase whiskers.? ? So now lead is bad and the powers that be decided to remove lead from solder, Reduction Of Hazardous Substances (RoHS).?? Now a whole new problem arises Tin Whiskers, so here the story takes a twist.? ?In the 30's whiskers were an issue because things were plated in tin, and pure tin has whisker growth.? ?NASA found out that not only tin but zinc, gold and silver also grew whiskers.? This is an issue because the growths are small wires a few atoms wide that cause short circuits.? ?Spacecraft have had issues, control systems in power plants, had issues and since the introduction of Rohs internationally issues are starting to show up.? ?Some whiskers need a microscope to see but others are quite visible to the naked eye.? ?I have seen whiskers 1/2" long about 2 thous in diameter.? ?If looking at pure tin and you see a white "mold" those are whiskers.? ?They grow from the base metal one atom at a time.? ?Google tin whiskers and go to the NASA website.? ?So if you have electronics that operate strangely you may need to shave.? ? pat? |
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Re: Harrison Timekeepers
On Fri, Jul 12, 2024 at 01:17 PM, Herman de Leeuw wrote:
teenage memories of the erstwhile psychedelic pop group Quicksilver Messenger ServiceAh yes, me too... I'm sure that we (the UK) would have called the liquid metal Quicksilver also, back in the days of alchemy no doubt. |
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Re: Metal fatigue or Zinc Pest?
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 Ed Samsen |
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Re: Metal fatigue or Zinc Pest?
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 Ed Samsen |
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Re: Metal fatigue or Zinc Pest?
Andrei
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From: [email protected] <[email protected]> on behalf of Dave Seiter <d.seiter@...>
Sent: Thursday, July 11, 2024 11:01:21 PM To: [email protected] <[email protected]> Subject: Re: [Unimat] Metal fatigue or Zinc Pest? ?
I've cast pewter over the years, and have never had a pour that eventually goes bad, but I get my raw stock from mugs and I reject any that look really old and/or have a white film..
-Dave
On Thursday, July 11, 2024 at 09:21:22 AM PDT, Davis Johnson <davis@...> wrote:
I see zink pest being bad two ways 1) Nice things get it and crumble. This is what we are mostly discussing here. 2) If it not for 1 above these zinc alloys would be very attractive for home casting. They melt at manageable temperatures, are machinable and reasonably strong. They are usable for small lathes for example. Just think how nice it would be to have a low
temperature casting alloy that was not prone to zinc pest. Build a small engine out of pewter, anyone? On 7/11/24 11:57, Mehmood via groups.io wrote:
I like the highly optimistic reference to 1960 being the date after which zinc pest could be considered ¡°largely free¡±. ?Presumably wicked casting fairies were all rounded up and locked in a high tower around then.
On 11 Jul 2024, at 16:21, ManfredV <manfredv1@...> wrote:
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Re: Harrison Timekeepers
Yes it is, sorry for that.
?
Mercury in Dutch is kwik,?in German Quecksilber so I inadvertently used "quicksilver" which may no longer be normally used in English but which does mean Mercury - all of which was further compounded in my mind by teenage memories of the erstwhile psychedelic pop group Quicksilver Messenger Service .. ah well, I digress?
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Re: Unimat 3 Pulleys, Thread/Tap Sizes?
Thank you Peter B and Peter A, I was about to order a couple of pulleys already bored to 13mm (for the M14x1 tap) when I discovered the M12 on the milling attachment. Good to have a group that can help cross-check. Cheers, Timothy Jump On Fri, Jul 12, 2024 at 12:18?AM Peter Brooks via <peter=[email protected]> wrote: At least M12x1 taps and dies are readily available as they are the ¡®other¡¯ (non-U3) Unimat standard thread. |
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Re: Unimat 3 Pulleys, Thread/Tap Sizes?
If you have a Unimat 3 then owning a M14x1 tap and die is a very useful addition
I bought one set, then acquired a second when I inherited some other lathe parts ( a little flexispeed lathe had been converted to M14x1 by a friend, and came with the taps and 5 chucks (2x 3 jaw (one set up internal, one external, 2x 4 jaw scroll chucks (one internal 1 external, and an independent 4 jaw chuck, it seems my friend didnt want the hassle of resetting the jaws, so just had one of each combo set for each use.) On Thu, 11 Jul 2024 22:04:59 -0700 "Peter Brooks" <peter@...> wrote: For the U3 the milling attachment is M12x1, and the lathe spindle is M14x1. -- Peter Ashby <aescinga.pgen@...> |
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Re: Unimat 3 Pulleys, Thread/Tap Sizes?
For the U3 the milling attachment is M12x1, and the lathe spindle is M14x1.
I would have expected them both to be the standard U3 M14x1, so was surprised (having made two pulleys for my DC motor conversion) to find that the milling attachment is M12x1. The moral of the storey is ¡®measure first¡¯ !!!? |
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Re: Metal fatigue or Zinc Pest?
I've cast pewter over the years, and have never had a pour that eventually goes bad, but I get my raw stock from mugs and I reject any that look really old and/or have a white film.. -Dave
On Thursday, July 11, 2024 at 09:21:22 AM PDT, Davis Johnson <davis@...> wrote:
I see zink pest being bad two ways 1) Nice things get it and crumble. This is what we are mostly discussing here. 2) If it not for 1 above these zinc alloys would be very
attractive for home casting. They melt at manageable temperatures,
are machinable and reasonably strong. They are usable for small
lathes for example. Just think how nice it would be to have a low
temperature casting alloy that was not prone to zinc pest. Build a
small engine out of pewter, anyone? On 7/11/24 11:57, Mehmood via groups.io
wrote:
I like the highly optimistic reference to 1960 being the date
after which zinc pest could be considered ¡°largely free¡±.
?Presumably wicked casting fairies were all rounded up and locked
in a high tower around then.
On 11 Jul 2024, at 16:21, ManfredV <manfredv1@...> wrote:
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Unimat 3 Pulleys, Thread/Tap Sizes?
Hoping someone in the group can verify the thread sizes (for the drive pulleys, not the chuck end) for the Unimat 3 lathe and milling attachment pulleys. I thought they were M14, but I just measured the milling attachment at 12mm.
For the milling attachment, is this an M12x1 or some other thread pitch? For the lathe spindle?? (I know the chuck end is M14x1. I hesitate to remove my current drive pulley on the other end of the lathe spinde as it is quite stuck but working fine, and I don't want to disrupt my current project.) Thank you, Timothy Jump |
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Mercury on the Loose
¿ªÔÆÌåÓýHi Gang: It has been a problem for years:
Think about telling your parents you boiled mercury on the kitchen stove, and now we need to strip the inside of the house! Carl. |
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Re: Metal fatigue or Zinc Pest?
Something?I picked up a while back when I was looking?for information on some of the cast items on my Emco Compact 5 lathe is that ZAMAK is generally considered the same as MAZAK, which strictly?speaking is not correct but they are very similar. You may do a search for MAZAK if ZAMAK does not give sufficient information. On Thu, Jul 11, 2024 at 3:11?PM Jkle379184 via <jkle379184=[email protected]> wrote:
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Re: Harrison Timekeepers
¡®Quicksilver¡¯ is the element Mercury I think?
When I was a kid we used to play with stuff on the school lab bench top, whizzing little balls of it about. Not a particularly good idea, the phrase ¡®mad as a hatter¡¯ apparently comes from the long term effects of the use of mercury in the manufacture of hats. |
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Re: Metal fatigue or Zinc Pest?
?I have cast small parts before using Zamak.? You can get the good stuff from electrical fittings, like flanges for thick wall tubing to cabinets or panels.? Plaster of Paris, Silicone spray mold release or Pam spray cooking oil. Spray part, mix plaster, push part into plaster. Let dry. Spray hardened plaster and part with release, Cover top with fresh plaster, let set, pull apart, Drill vent and pour holes. Small SS cup, mine was a part of a condiment serving set. Set on fire brick or hold up with wire stand, heat with propane torch, add Zamak pieces, melt, skim off slag and pour. You will also need to bake the plaster before using to drive off any moisture. I used paper Dixie cups with plaster poured into them for molds. You may also have to add thick big washers on the top to keep the top from lifting. easy to do and Zamak is a dream to machine. ?Jeff
On Thursday, July 11, 2024 at 12:21:20 PM EDT, Davis Johnson <davis@...> wrote:
I see zink pest being bad two ways 1) Nice things get it and crumble. This is what we are mostly discussing here. 2) If it not for 1 above these zinc alloys would be very
attractive for home casting. They melt at manageable temperatures,
are machinable and reasonably strong. They are usable for small
lathes for example. Just think how nice it would be to have a low
temperature casting alloy that was not prone to zinc pest. Build a
small engine out of pewter, anyone? On 7/11/24 11:57, Mehmood via groups.io
wrote:
I like the highly optimistic reference to 1960 being the date
after which zinc pest could be considered ¡°largely free¡±.
?Presumably wicked casting fairies were all rounded up and locked
in a high tower around then.
On 11 Jul 2024, at 16:21, ManfredV <manfredv1@...> wrote:
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Herman de Leeuw
Carl