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Preserve zinc weights

Started by pacifier, May 31, 2007, 12:06:34 PM

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pacifier

Is there a treatment that will help to preserve the zinc weights found in the old Rivarossi Cab Forward steam engines. I read of someone that used a treatment of that metal somewhere on the internet, but don't remember where I read it or what he did. I have two of these engines, in one of them the zinc weight looks like it is just starting to deteriate.

r.cprmier

Zinc or "Zamac"?  Zamac will deteriorate after a time, as it is really nothing more than the old compound that was used in typesetting in the old newspapers linotype operations, et al.

Boilers are usually made from this same compound.  It is a great weight, but is fallable.

the best weight by far, is lead, but just be careful if you use it.  An interesting thought:  SOmeone once told me that if you could put stardust into a teaspoon, it would weight a quarter of a ton.  Interesting...

RIch
Rich

NEW YORK NEW HAVEN & HARTFORD RR. CO.
-GONE, BUT NOT FORGOTTEN!

Hunt

Zamac -  acronym for Zinc Aluminum Metal Alloy Casting

If Zamac is at the point of disintegrating into powder there is nothing you can do; but, if there is just cracking -- coat with a penetrating formula CA.
Example:
Zap-A-Gap CA
Filling Adhesive
Super-Thin Penetrating Formula
Made by Pacer Technologies

Don’t use the  Zap-A-Gap CA+

ebtnut

Zamac was the "metal of choice" for die-cast railroad models in the 50's and '60's.  Not sure what Bachmann is using in its models.  Folks like Varney, Mantua, Roundhouse, and English used it extensively.  It's one drawback is the reaction if contaminated by even the smallest amount of lead.  The chemical reaction takes years to become noticeable, but is untreatable.  The John English models were especially prone to this problem.  The treatment with ACC noted above might give you a respite, but ultimately you may want to replace it with a piece of steel or brass of about the same size.  If it fits into a cavity, crush in some lead wool around the piece to hold it in place and add some extra weight.

RAM

Zamac -  From what i understand, Was good in it was mixed correctly.  It was used for car parts.  They mix up large amounts.  The problems really came in when mixing small amount.  Just a little too much of this or that and you had a poor mixture.  I have some 60 year old model that still look to be in great shape.  I had some that in just a few years fell apart.  I never heard of Samas being used in printing.  all of the printing block I have are lead. 

Woody Elmore

When I joined an HO club years ago there was a printer who used to supply lead linotype slugs for car weights - definitely not zamac whic was brittle.

I have seen people use epoxy to glue lwngths of solder to the main sills under an HO freight car.

another idea is to get the smallest shot you can find and fill a cavity with  either shot mixed with epoxy or silicone caulk.

r.cprmier

I had some that in just a few years fell apart.  I never heard of Samas being used in printing.  all of the printing block I have are lead. 

While I am not expert on metal composition, I find it hard to believe that a material as soft as lead would, by itself, be used in a typesetting application.
I did a project at the "Hartford Times" many years ago, and thought that  "Typemetal" was great stuff to use in this application, as it is a better compound than just plain lead.

For weight now, I just use 1/2" nuts for cars; unless I am looking for some really weighty solutions; then it is back to the birdshot/"balloon" thing...

RIch
Rich

NEW YORK NEW HAVEN & HARTFORD RR. CO.
-GONE, BUT NOT FORGOTTEN!

Woody Elmore

I am not sure of the exact composition of the linotype slugs but they were definitely as soft as a lead bullet. Maybe they contained antimony or some other metal that I now wish I hadn't handled.

At one time at narrow gauge meet in Maryland I saw a Maine 2 foot flatcar which had the space between the two center sills filled with shot and epoxy. The operator of the module was interested in operation and didn't bother with any kind of brake system. His weighting was unobtrusive and would work well with any larger model.

r.cprmier

Woody;
I am not knowledgeable of the exact proportions, but the stuff that wound up in the linotype room on a daily basis, was a combination of lead, tin, and either zinc or antimony.  Call me wrong if I am.  This stuff was fairly brittle-that is, it wouldn't bend much without stress ruptures.

If you want to talk about something to worry about, why not try the after effects of agent orange?...

Rich

Rich

NEW YORK NEW HAVEN & HARTFORD RR. CO.
-GONE, BUT NOT FORGOTTEN!

Woody Elmore

I am very familiar with the effects of agent orange. A high school-college friend of mine flew planes in Viet Nam that sprayed the stuff. Apparently it used to blow into the cockpit.  He has really bad health problems - and even worse problems with the VA!

As a kid I remember that my uncle used to melt lead to use as packing, with oakem, on cast iron waste pipes. I wonder how much harm is caused by the solvents used on plastic plumbing.

I have also heard of the lung damage caused by spraying Floquil and Scale Coat paints that have zylene as a solvent.

When I asked a chemist friend for some MEK years ago (I wanted to try it on plastic) he wouldn't givce it to me citing the danger to the lungs.