Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Other Topics => Topic started by: kagliostro on September 11, 2023, 04:15:41 am
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What was/is used to mount the threaded rod bar on HV Line Ceramic Insulator ?
To give a look to the material it seems a sort of cement
Thanks
Franco
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yep, it's how the west was won :laugh:
the smaller ones were used mostly for telegraph lines, usually a threaded wooden stick would go in the base to attach it to the poles.
i've got a few i scrounged from ol rail lines i'd walk. great for sighting in the iron sights also :icon_biggrin:
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That is porcelain. The entire insulator is cast of brown porcelain clay. Then the outside is given a white glase coating to make it smooth and pretty. Same as your toilet. Prety white glaze coating on the outside, light brown on the inside.
Any threaded rod would have been secured on each end with matching nuts and washers.
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So in your version no cement inside to secure the threaded rod
You can see residual of the cement on the photo I posted
Franco
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What are you calling cement? That brown stuff is just the color of the porcelain that did not get glazed. I bet if you crack that insulator open with a hammer, you'll find that the entire insulator is that light brown color. The white color is only skin deep.
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The guy who asked in a forum where I read say that is surely a sort of cement incorporating some filaments of unknown material (if you enlarge the image you can see something), and not part of the insulator
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About material construction I remember also a time when you can see glass insulator with the same shape
Franco
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most of the one's i've found for telegraph were glass, some had a wooden core that was threaded to mate with the male wood post on the pole. the porcelain/ceramic ones used for ACv appeared to have some sort of "glue" to bond to metal "arms" used to attach to poles.
it's way to rainy n cold to venture to the barn for a closer look/pic, maybe in the morning
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I have seen this. A dull brown paste distinctly different from porcelain, ceramic, or glass (or now polymers). Always up inside the insulator so it won't stay wet. It frankly looks a lot like the wall "plaster" in my house from the 1800s, which was more sand than lime, mixed with shaggy horse hair.
Wikipedia says there are all kinds of "plaster" (https://en.wikipedia.org/wiki/Plaster) from clay to portland cement, and all sorts of fillers and binders. Manure adds both fiber and protein (sticky).
There are people who study insulators with a passion, and they must have websites?
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I found this on FaceBook, covering some of the things used to improve clay plaster. (I did not know that cow poop was 'magic'.) He's making walls and sinks, but this was a common technology in early days of electricity.
https://www.facebook.com/groups/naturalhomes/posts/4185018061513402/
Sigi Koko
December 30, 2020 ·
I wanted to share a little primer on clay plaster & additives, as these questions seem to come up quite regularly.
What is clay plaster?
At it's most basic, clay plaster contains 2 simple ingredients: clay (which acts as the sticky binder/glue) & aggregate, such as sand (which reduces shrinkage cracking and improves compressive strength). Water is used to activate the clay and make it sticky. Once wet, the plaster is malleable and can be shaped to whatever your purpose is. Clay plaster hardens as it dries out (ie, as the water evaporates back out).
Clay is found in soils around the world. And mostly the clay soil already contains some sand.
Other additives:
There are so so so many other things you can add to clay depending on what you are trying to do with it. Here are a few of the most commonly used additives, along with why you would use them.
fiber - gives you a support network inside your plaster...like an armature or woven fabric integral in your plaster. Most often fiber is some kind of chopped straw from grain farming. But can also be hemp (fiber, not hurd), sisal, palm fronds, hay, etc. Any dried fiber that is pliable and not super smooth will work. The more fiber you add, the more flexible and gravity-defying your plaster becomes. A plaster that is 50% fiber will bridge dissimilar materials (ie, let you plaster over wood studs), and allow you to build out thick relief sculptures (or just super thick plaster).
horse manure - easy way to add chopped fiber to your plaster
cow manure - adds some fiber and some stickiness (binder). Cow manure can be used to amend super silty or weak clays to improve strength. Plus the magic of cow manure is an enzyme that helps any plaster improve resistance to erosion from water. So it's a great additive for exterior plasters, plasters in wet areas, or clay floors.
wheat paste - this is simply flour boiled in water to create a thickener. (Other starches work as well besides wheat.) Wheat paste adds stickiness, so helps to improve weak clays. It most commonly is used to strengthen and prevent dusting in finish plasters.
pigments - clay is naturally occurring in a plethora of colors (white to yellow to orange to red to burgundy to purple to blue to gray to black). You can also add any variety of pigments to augment or change the color of your clay. Note that your base clay color is part of the palette so it's easier to darken a plaster than lighten it up.
I personally do not add lime to clay plaster. It's often feasible, but it's tricky, and depending on the mineral makeup of your clay soil, you can change the chemical curing of the lime so that it becomes hydraulic. So if you are just learning plastering, I personally would steer clear of adding lime. (Plus the lime is caustic, so you can no longer touch your plaster with your hands safely.)
....all the wild and beautiful things you all are doing with clay plaster 🙂
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Many thanks friends
Thanks for the link PRR
This is a really interesting text, I know only a small part of the things that are explained there
To me is very intriguing to discover and know the old forgotten techniques adopted by our ancestor
Thai is fascinating me
Thanks again
Franco
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a couple i scrounged walking abandon railways in America
the threads are cast into the comm's insulator, the AC one has a "wood-like" plug, that IIRC is threaded into casts.
had a pretty large collection, found they work really well as gifts for those obscure 3 year-olds in the family tree
too big to swallow, no lasting damage if they drop it on their toes..... :icon_biggrin:
sold some, going price for my best piece was ~~$15, averaged ~$5
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Some of these glass insulators were on threaded wood pins (posts) wedged into wood cross-bar. There may have been a wood-threading machine in common use. We found hundreds of these behind a farmhouse we bought. I think the farmer was standing by the road when the lines were upgraded, and took everything away. Some crossbars became framing in the cellar, others in the garden. They all had either threaded wood posts or stubs where posts were cut off. They also REEKED of old coal-based creosote and stained everything they touched, even though many decades old.
Shooter has that but the wood (or something) made short and an iron bolt to go to the crossbar. This may be slightly stronger than a wood pin. (Heavy ice is common here.) Maybe cheaper than having new glass insulators threaded for iron bolt. Or just because glass on iron may crack from heat/cold or rust.
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threaded wood pins
I had some wood pegs, most though I unscrewed since the pegs were still attached to the cross-bar and that wood is had to break off.
They also REEKED of old coal-based creosote
had a couple teens on a WV climb, they wanted to take the backroads home, so i'm driving n spot an old stone faced train-tunnel, the boys wanna play on it. It's Sunday morning so we scramble up the face, then I feel it!!!! I had the boys lock off on some scrub-trees above the opening, the train is rattling the tunnel, chokin out the diesel, dust rising EVERYWHERE. Kevin n Bo thought that was the greatest thing they'd ever done!!!! The jeep stunk of weeks, their parents asked them if they lived in the fire-pit!
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Some of these glass insulators were on threaded wood pins (posts) wedged into wood cross-bar. There may have been a wood-threading machine in common use. We found hundreds of these...
"Unlimited quantities":
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no middle man needed, forest to telegraph line workers, probably shipped on the rails with all the dimensioned lumber
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Thanks for sharing PRR
I like those old papers
Nice the lineman climbing tool
I think I've seen it in use when I was young
😁👍👍👍
Franco