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Posted By: ynot Glass Globe Lense Manufacturing! - Tue Nov 14 2006 04:18 AM
How are all these lenses produced? Are they still processed the same as as the originals?

Have heard they are frit painted, then convex formed in a mould using heat and natural gravitation. Possibly they're silk screen or flat glass painted, then moulded as some have suggested?

Has the manufacturing process changed over the years? Has or does anyone use the pad printing process?

what about the more recent and much smaller, one piece mini display globes? Are their faces just painted or silk screened on?
Posted By: +Chris Holt Re: Glass Globe Lense Manufacturing! - Tue Nov 14 2006 10:04 AM
T-Way where are you
Posted By: travis_towle Re: Glass Globe Lense Manufacturing! - Tue Nov 14 2006 05:16 PM
I always wounderd how they made them back then and how that process compairs to todays.

Is there any SPOT CHECK way to tell if a lens is an unmarked repop by looking for process marks?


Travis E. Towle
Topeka, Kansas

785-357-1004
Posted By: T-way Re: Glass Globe Lense Manufacturing! - Wed Nov 15 2006 11:56 AM
ynot:

I can't speak for anyone but us - but our process is EXACTLY like they did it originally.

Silk-screened on flat glass one color at a time . . .
then heated in a kiln until the glass gets 'plastic', then gravity slumps the glass into a SS mold.

Pad-printing is not an option as the frit is too thick for that process - and it doesn't deposit enough material to make the colors opaque.

We don't produce the small globes - but my opinion from looking at them, is that they are fired-on decals on glass bodies.

Travis:

Experience is the best guide for spotting fakes. The newer reproducers use much finer screens that a lot of the old lens manufacturer's did. And the 'white' on the back is usually much smoother than what is normally on an original.

Later . . .

Jim



Always buying Ethyl Globes, Ethyl Single Lenses & Misc Ethyl Items.
Posted By: thermactor Re: Glass Globe Lense Manufacturing! - Wed Nov 15 2006 09:29 PM
T-way,

Thanks for the info.
I have a couple questions that I'm curious about.

I take it that the notches were ground in after the glass was sagged?

What type of cooling process does the glass go through - I assume there is some kind of controlled cool-down event?

Also, by what ratio does the outer diameter of the glass change during the sagging process?

Thanks,
Wes
Posted By: T-way Re: Glass Globe Lense Manufacturing! - Wed Nov 15 2006 10:45 PM
Wes:

Yes, the notches for 13.5" lenses are ground after the slumping process. We grind ours 'deep' so they fit Capco's and glass bodies. If you want lenses for 'banded bodies', we can ship you 13.5" lenses that have not had the notches ground.

Cool down is just air-cooling. Anealing takes place at that time - no special anealing unit or lengthy cooling process is needed. This is, after all, flat glass - not 'art glass' that has been worked from molten to a finished shape. That type of glass takes a lengthy anealing process.

The reduction ratio is very small. I don't have an actual figure - but the original screened art is not much larger than the finished (slumped) lens diameter.

Later . . .

Jim
Posted By: ward zaharia Re: Glass Globe Lense Manufacturing! - Thu Nov 16 2006 01:47 AM
Jim

Since we are all getting a question in how do you cut your glass blanks. I have heard some companies use water jet machines and also cut the notches with them before they are slumped.
Posted By: T-way Re: Glass Globe Lense Manufacturing! - Thu Nov 16 2006 12:38 PM
Ward:

Again, I can't speak for anyone else - but right now we hand-cut our glass to the starting dimension needed. After firing, then we do the notches.

With our process, having the notches done first would not save us any time. For us, it's easier to do them afterwards.

I am going to look at getting my 'blanks' cut at the manufacturer. That's something on my list to do over the winter.
(It can be a pain to spend an entire afternoon cutting circles . . .

Later . . .

Jim
Posted By: travis_towle Re: Glass Globe Lense Manufacturing! - Thu Nov 16 2006 03:13 PM
Wow - lots of HARD work Jim - keep up the GREAT JOB!

I need to get you my Tioga Globe - and now I have an ETHYL that I just got a price on from the original business owner in Iola Kansas! I want to get these made so I can sell off the originals.

All in dear time my friends!


Travis E. Towle
Topeka, Kansas

785-357-1004
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