Where to buy Prince Rupert's Drop

I'd like to see just how often one forms, so I might try making some. If I get more than one, what kind of price are you offering? It sounds like small is more likely to work than large....

Regards,

Mike

That's the thing...I can't find this thing anywhere on the net, so I have absolutely no idea how much they generally cost.

Once one gets the trick of making them, they are fairly easy to make. One needs to build up a hot blob of glass that will drop free of the pipe or rod of glass and as it starts to fall into a container of water, pull/jerk the hand up to pull the tail clear of the falling blob so there is no long thin thread. Small ones - 1/8-1/4" - are easier in the torch, larger - up to 1"- easier from a pipe. If you don't do it right, you end up with spinnerettes of glass in the water, so you are picking the drops out of threads of glass after letting them cool down (especially the larger) in the water. Small ones should be broken wrapped in cloth, large ones double wrapped and tightly held - otherwise tiny fragments of glass are flying all over instead of making a small forceful whomp. When demostrating how strong the head is (hitting it with a hammer) hold the tail carefully and have some eye protection.

-- Mike Firth Hot Glass Bits Furnace Working Website

shows recently changed files, click on link"Keith Patrick" wrote in messagenews:zyi4b.22096$ snipped-for-privacy@twister.austin.rr.com...> That's the thing...I can't find this thing anywhere on the net, so I have> absolutely no idea how much they generally cost.>> "Mike Beede" wrote in message> news:300820032059500721% snipped-for-privacy@visi.com...> > In article , Keith Patrick> wrote:

What is a Prince Rupert's Drop and what are they for?

They look like a tadpole of glass. Basically, the rapid cooling puts a tremendous amount of pressure on the inside of the glass due to the surface cooling (and shrinking) more quickly than the interior. As a result of the stress, the bead is extremely strong and can withstand hard strikes with a hammer. However, if the tail is broken, the pressure is relieved, causing the drop to explode into a powder.

Patrick

is this the same thing a s a Russian tear drop? sounds similar in shape but i never tried hitting one with a hammer! If so , i have a few i can part with. michele

Probably not. The few returns I get on Russian tear drops that are not references to songs are obviously decorative tear shapes which are carefully annealed. Like the icicles that have become popular the last few years. A Prince Rupert's Drop is a scientific curiosity created by violating all the normal rules of working with glass. Other than hitting it with a hammer to show strength and destroying it to show failure method, they are useless.

Steve J. Noll | Ventura California (zone 10) | Glass Block Pond

I can make them for you, along with " Baloney tubes" They are similar to PR droppings, only they are a hollow tube. I would demonstrate them by driving a spike in a block of would using the Baloney tube as a hammer. I then drop a micro piece of silicon carbide down the tube to make it explode, and I mean EXPLODE. You do this while it is inside a Zip lock bag to contain the shards.

Randy Hansen SC Glass Tech San Diego, CA

OOoh! I saved a nice description of how the drops are made....wanna tell me how a baloney tube is made?

Bryan "I hunger for knowledge and thirst for experience" Paschke

HI Bryan,

They are made essentually the same way. A PR drop is made from soft glass. I just frorm globs on the end of a rod and let them drop off into a bucket of ice water. You will loose better than 50% of them. But the ones that don't crack are what your looking for. After retrieving them from the ice water I burn off the long tail to make the tear drop.

For a baloney tube I use boro. I like to use about a 3/4" heavy wall. (if you use it as a hammer you need the wall strenght.) These are little more tricky. It's more like what Mike said, you sorta just dip the cherry red part of the ball on the end of the tube into the ice water. If go to deep you cause cracking on the tube. Again you loose more than you keep. After they're cool it's a good idea to keep them under wraps. They sometimes explode for no reason.

It makes a cool demo. To see how strong the glass is at the same time it is so week, that just a speck of silicon carbide dropped into the tube will cause it burst.

If you do try to drive a spike into a block of wood (spelled it right this time!) Were goggles or a face shield, and don't let people watching get to close. ( had to say that for legal reasons)

Good luck,

Randy Hansen SC Glass Tech San Diego, CA

So do you actually have to use ice water, or is just plain old room temperature water okay too? Is it just that you get a lower yield or is the yield zero?

Mike

The way I was shown how to do them was with as much ice as you could hold in the bucket. I haven't actually tried it any other way.

Randy Hansen SC Glass Tech. San Diego ,CA