Threading glass?

[Greg Cowles]

Does anyone know how to thread glass?
Tap and die, use a mold?
I see it available through scientific suppliers, but I really need to be able to do it myself.

[art vandelay]

http://www.sha.org/bottle/Finishes/closedmold.jpg

I cant find anywhere that sells the mold but you can make your own mold easily out of scrap graphite (if you are just making the thread part, the whole bottle mold would not be easy to make.) Or you can by those cheap threaded test tubes and use them the same way you would attach any other premade joint.

[Kool]

Hand tools exist for making threads on glass. I remember seeing really old ones before.

[Slow]

Eskuche does it with a clear stringer and mad skill.

[ineedanewusername]

Would happy skill work too?

[ineedanewusername]

But seriously, I have been looking for these too, but would need something bigger than a tap n dye set, like for a mason jar

[menty666]

If you can get the mold right, you can just blow into it to create your threads.

The devil here is in getting a mold that you can use and then getting the glass back out of it, because just blowing into a carved cavity means you'll need to unscrew your still soft glass from it, potentially moving the threads. That's why "real" ones swing open like that.

[art vandelay]

all blow in molds have to be hinged. i wouldnt attempt a tap n die thats probably just gonna break glass. a stringer to add threads would work but it would take ridiculous skill to do it right often. blow in casts are how all mass produced glass containers with threads are made. dont try to reinvent the wheel, just take out the dremmel and start making your own casts. if you get them good enough you can use them forever to make production jars that match pieces you sell.

[art vandelay]

the real issue is why bother when a cork is soooo much simpler

[menty666]

the real issue is why bother when a cork is soooo much simpler

The challenge is what keeps it fun

[art vandelay]

true

[Greg Cowles]

Thanks guys, I appreciate the input.
Working on some ideas for a new product, and I'm needing to thread both inside and outside of some small tubes.
8-9mm
Casting has My brain churning.

[BlueBeard]

sounds like ya want to make it on your own but check out ace glass. they make all sorts of threaded glass and may have what your looking for.

[Greg Cowles]

Thanks I'll give them a look.
The problem I've run into so far with buying something premade is anything 8-9mm with threads on the outside is attached to something $50 or more.
Not really seeing anything that size threaded on the inside.

Thanks for the tip.

[brads]

Hand tools exist for making threads on glass. I remember seeing really old ones before.

Here's an old hand tool for making threads that's quite likely from the 1800's. The individual parts of it are obviously hand wrought and the mark stamped into the inside of the handle is "T.C.W.& CO.", which is the trademark that the TC Wheaton Glass Company used in the 1800's. After 1900 they dropped the "&" from the mark. They later used various other marks, but the "T.C.W.& CO." mark was their first. "Millville.N.J." is stamped underneath that.

I picked this up with a bunch of other oddball stuff at a yard sale in Millville, NJ back in the 1980's. It's been a very long time and the details are fuzzy, but the way I remember it is that the people holding the yard sale were the 3rd or 4th (maybe 5th?) generation of a lampworking family and inherited the house when their father recently died. According to his daughter, their old lampworking shop out back closed down in the 1960's after the family's kids decided that they wanted to do something more lucrative - and less hot and sweaty - than production lampworking. Because I was also a glassblower I wound up getting a tour of the (very dusty) shop which, until they recently started cleaning it out, had been closed up for probably 20 years. Although their father had sold off most of the equipment there was still some interesting stuff lying around here and there. I left with a couple of boxes of old tools, some glass tubing, and various other stuff. The threading tool in the photos below is one of the tools I got.

[Kool]

That's really cool, thanks for posting. That is very similar to what I saw.

[menty666]

Those old tools are awesome. For all the advances, those old bits got the job done.

[yinzer]

Ohhh!! I want that!!

[brads]

Ohhh!! I want that!!

Send me an obscene amount of cash and it's yours.

I took a few more detailed photos of the tool to better show the TCW stamp and the threading part of the tool. I don't think it was obvious in my other post that the threading part of the tool actually slides back and forth about 1/4 of an inch. These photos may show it better. Although the arrows in the photos only point to the sliding part on one side, the threading parts on both sides of the handle slide back and forth.





The screws that hold the sliding threader in the tool ride back and forth in slots. When fully tightened they bottom out so that this piece can still slide. The photo below is a closeup of those screws and the slots.



Last, a better shot of the stamp on the inside of the handle.

[D. dino i ninjah]

Have you ever used the tool .. if so what were the results like ?