I have a Pyrex glass crystal timer, with a patent date of 1920, that I am getting ready to install on my engine. Unlike most crystal timers, neither the pot metal ring nor revolving contact mounting have swelled, cracked, or deteriorated.
1. What causes pot metal to swell?
2. How long do you think the parts in my crystal timer will last before they start to deteriorate?
3. Has anyone installed a good crystal timer, only to have the pot metal parts begin to swell?
4. What are the warning signs that the parts in a crystal timer are failing?
5. Is there anything that can be done, such as soaking in a preservative type solution, to preserve pot metal so it does not start to swell?
6. Isn't there someone who makes new replacement parts for the crystal timer?
Most "pot metal" is of dubious composition. Formula constantly changed based on what the cheapest additives around were. Therefore, finding the right cure can be a detriment in itself by the time you figure it out.
In the music box world, the generally accepted practice for a "survivor" on pot metal parts is to simply seal the air and environment out by using 3-4 coats of crazy glue. Don't know how it would hold up in a higher heat enviornment, but short of someone chiming in, that's a place to start.
There are, or have been ads on the classifieds for this timer off and on for some time. Maybe you could contact the seller as he list them as is, like the one you have or with new ring installed so they can be used.
Hmmm – Could this timer be one of the first uses for ‘Corningware’ ?
C. C. Manning
Corning, New York
Patent number: 1355682
Filing date: Sep 22, 1919
Issue date: Oct 12, 1920
Corning also made glass hood ornaments.
Art, please check on this timer. It has a March 15, 1921 patent date and was made in Ridgely, Maryland. The designs are so close that there likely was a patent infringement law suit and the Crystal Timer may have lost. Why else would so many of those units have been stored for so many years?
Replacement for the Crystal timer pot metal ring can be obtained from Bob Scherzer.
To my knowledge no one has come up with a replacement pot metal timer brush carrier.
This was discussed on this forum earlier.
Ron the Coilman
Ron, I have some Crystal Timers and some of Bob Scherzer's aluminum replacement rings, but I don't have any information on that Eagle Timer and have not found any details.
Our T club meets in the town where that one was made and there appears to be a lot of them around yet too. There is absolutely no information on the company or who owned the patent though.
With a little work, could you use a New Day brush?
Be careful -- Corning ware is a glass ceramic that was developed by Dr. S. Donald Stookey, in 1953. It was first available commercially in 1958.
Pyrex is a borosilicate glass that is well know because of its low expansion. It was used for battery jars and in 1913 Bessie Littleton asked her husband, a Corning scientist, to bring one home and she baked a cake in it. By 1915 it was a Corning cookware product. Pyrex glass was actually used as early as 1908 for for railroad signal lanterns.
Are you sure that the glass head shown mightn't be Laleak (bad spelling). spelling is not one of my strong points, thank goodness for spell check
Mark, Spelling isn't my strong point either, and getting worse as time goes by.
Actually the mascot is a corning product even though it looks very similar to the Lalique.
Here's a good website that shows a lot of different examples of really great hood ornaments.
Jim, Sorry about the hijack.
The first three of following patents were issued on the date in
question, with the first one matching for Ridgely, Maryland.
The next 2 patents are included in my list because the issue
The fourth patent’s date does not match, but I included it
because of the EAGLE, Michigan connection - Just a long shot.
Ira T. Leager
Patent number: 1371697
Filing date: Apr 28, 1919
Issue date: Mar 15, 1921
Albert E. Smith
Assigned to Milwaukee Auto Engine and Supply
Patent number: 1371940
Filing date: Sep 12, 1919
Issue date: Mar 15, 1921
Edward B. Jacobson
Assigned to J and B Manufacturing
Patent number: 1371972
Filing date: Sep 13, 1919
Issue date: Mar 15, 1921
James D. Reed
Patent number: 1345402
Filing date: May 2, 1919
Issue date: Jul 6, 1920
Is there a problem with the brush holder on the crystal timer? I looked at doing them but didn't hear of a complaint. If I do make them I would redo the spring set up like the one used on the Eagle timer and others that used a coil spring and weren't guys just using brush holders from other similar styled timers if is a theirs was missing or broken?
Ron if you are at Hershey stop over I have some of the rings you wanted. Sorry I didn't have them sooner it's been a rat race trying to get all the orders done on time "as usual". With Fritz gone I'm like the one legged field goal kicker. Bob
The problem with early "potmetal" was trace amounts of lead in the mixture. The process is called "die casting". The part produced could be used as cast and required no machining. This of course drove down the cost of making the part. The lead helped the part to release from the die. Unfortunately the lead ultimately made the part swell and fall apart a few years later. So it took them 5 or 10 years to figure out that;
1. there was a problem,
2. what the problem was
3. how to solve it
And so virtually all die cast potmetal from the 20's and early 30's has this problem.
Art, thank you ever so much! This is an early Christmas present!!!
Your welcome James - glad I could be of some help.