Anybody have a background in etching glass?

[TelePlay]

I've never seen this before on glass and have no idea of what happened, made this way or exposed to something over time decades ago.

This lantern globe is mostly frosted but the area in this photo to the right shows smooth glass. The surface to the left is mostly frosted. Between the two is an area of what reminds me of how frost forms on windows in the winter. Curved threads that crisscross each other and if enough of these crossed, the glass becomes totally frosted.

It's in the glass surface, not painted but etched. I know HF acid gas can do this but when done, I would not expect to see the "lines" between the clear and frosted areas. The lantern metal is in fine shape.

So, what happened to this globe which is 85% frosted 10% partially frosted and 5% not frosted. Any ever see this before and anyone think they might know what happened, like putting a hot glass globe in an industrial environment where the "air" would affect the hot glass surface?

I know nothing of glass but this chemical process of the surface is interesting. Can anyone help?

[NorthernElectric]

It looks similar to the sort of mineral stains like you might find on dug glass.  I have a red Adlake Kero globe from a railroad lantern that I dug that is worse than that.  Is that red glass or is the red flashed?  If it's red glass you can try soaking it in a mild acid solution for several days.  If you can find oxalic acid crystals, that's what I used to use on insulators.  If that won't clean it up, there are folks who tumble old bottles and insulators.  If there's embossing on the glass tumbling will weaken it though.  If the color is flashed on, I don't know how you'll clean it.

[TelePlay]

Is that red glass or is the red flashed?

It is solid red glass. I tried steel wool on it in a spot, no affect. I tried an exacto knife on a few lines, no effect. I tried my finger nail on an area and ground down my finger nail. Tried HCl acid and no effect. Will try oxalic when I find some.

[NorthernElectric]

Tried HCl acid and no effect. Will try oxalic when I find some.

If you tried HCl and it did nothing then the oxalic may not help, as it is pretty mild.  The advantage of using oxalic is you can put your hands into it.  You will need to immerse the globe in it and let it soak for a day or a week or 2.  It will sting a bit if you have cuts but you can just rinse off.  It's not highly corrosive as HCl.  Did you soak it for a while in the HCl or just wipe on-rinse off?  If you haven't already, try soaking it for 48 hours.  Superficial mineral stains can clean up nicely, but if the minerals have etched deep into the surface, you could achieve an improvement but still have swirly marks when you're done.

[unbeldi]

The pattern looks very fractal to me.  It seems the glass surface has crystalized along scratch lines or other defects.
Surface crystallization is known in certain glasses and can be induced in a controlled manner, sometimes to strengthen the glass.

[TelePlay]

The etching seems to be into the glass. Why the pattern and why some areas near the base are clear, don't have a clue. The etching is very heavy toward the top of the globe and shows patterns toward the bottom where some of the glass has not been etched.

Working on the lantern that it came with, I was first surprised to see that this is a 1941 Dietz, one of the last produced with tin plating, produced just before they switched over to Terne plating because tin was needed in the war effort. I've always wanted a 40s tin but wish it were in better condition.

Seems whatever affected the glass also had an impact on the tin plating. The photo below has a red tint and that red is rust, thick rust but only in areas. The air tubes show more or heavier than the fuel font or the chimney. Wherever this lantern was used, it must have been exposed to something in the air that affected the tin and glass.

Still working on the lantern, been in the molasses bath for a week now, and is getting better after 3 Brillo rub downs, but it needs more time in the bath.

Took the top off of the pail and got a bit of a chill up the spine. Looked like someone was sending a message, second image below.

After looking at it, realized the big round circle was the outline of the bottom of the fuel font, the small circle is the fuel font opening, the two "m"s are the air tubes and the big "X" is the outline of the globe wire cage (I put the lantern in with the cage tipped backward.

The "bubbles" must be the byproduct of the sugars working on the tin plate rust, an interesting but slow process.

As for the glass, I can get a NOS globe for $16 and if the metal turns out okay, will do that rather than mess with the etched glass globe, which can still be used if a dull red lamp light is needed.

[19and41]

With combustion byproducts causing acid rain, I wonder if the cycles of allowing the lantern to use up it's fuel and go out might allow condensation on the globe to become acid.  In cold weather such condensation could freeze up and then be dissipated in a heat cycle, leaving erosion where the frost deposits were.  Such damage to the glass could be accelerated by the heat.  It's not far fetched, either.  I saw a program about the restoration of stained glass windows in Europe that had their surfaces eroded by acid rain from polluted air.