My Tungsten Cube (2019) • Hacker News Board

Re: My Tungsten Cube (2019)

#331

Post by code_duck » Sun, Aug 29, 2021, 12:20 PM UTC

skykooler wrote: post #109

code_duck wrote: post #61

I have a collection of thin tungsten cylinders if anyone is in the market! Glassblowers use tungsten rods to pierce borosilicate glass. When you get tungsten and a piece of glass hot, you can push the tungsten through the glass fairly easily. Tungsten doesn’t get “wet” and stick to glass at these temperatures (~2000F), unlike other metals we use such as steel or brass. We tend to buy these at the welding store (arc w…

Note that if you're buying welding tungsten as a plaything, avoid the oneswith the red paint on the end - they contain thorium to improve the electrical arc and as such are a bit radioactive, and shouldn't be directly handled for long periods.

Indeed, the thorium ones definitely shouldn’t be put into a 5000 degree flame 2 feet in front of your head. All the other metals in glass work are bad enough.

Re: My Tungsten Cube (2019)

#332

Post by tcspence » Mon, Aug 30, 2021, 1:23 AM UTC

I have a block of tungsten about the size of my fist. Got it at a missile test range. When the explosives are replaced by the telemetry unit, empty space is packed with tungsten to make up the weight difference. The target area was filthy with tungsten blocks.

Re: My Tungsten Cube (2019)

#333

Post by lobocinza » Mon, Aug 30, 2021, 4:44 AM UTC

tmm wrote: post #295

dreamcompiler wrote: post #277

Earlier quoted context omitted.

Or you could just not wear rings at all. I'm an EMT and the only trauma injury that gives me the creeps is degloving. Happens e.g. when somebody falls off a ladder and their ring gets caught on a nail on the way down. Don't google it.

> the only trauma injury that gives me the creeps is degloving I worked with a guy who was missing most of his ring finger. I asked him about it one day at lunch. I regretted it.

Specially maxillofacial degloving. But modern surgery is amazing.

Re: My Tungsten Cube (2019)

#334

Post by Doxin » Mon, Aug 30, 2021, 7:18 AM UTC

hexa22 wrote: post #316

Doxin wrote: post #300

Earlier quoted context omitted.

I can hardly see lead chipping, it's much too soft for that. In general handling lead in its solid state is pretty safe. It's mostly lead dust you'd need to worry about. In any case washing your hands after handling lead is pretty much a foolproof way to be safe. It doesn't absorb through the skin.

You wouldn’t want to be handling it like a desk toy..

Probably not no, but as a display item it's absolutely fine. You're not gonna ingest lead from just touching a cube of lead every now and then.

Re: My Tungsten Cube (2019)

#335

Post by MisterTea » Mon, Aug 30, 2021, 12:25 PM UTC

e12e wrote: post #204

MisterTea wrote: post #164

We use blocks like this in our electron beam welders to set the beam power, shape and focus on older machines (newer machines use a CPU/DSP controlled system). A small 25x25x50mm block sits on an adjustable height stand which is set to the height of the weld joint. You dial in the settings, hit the block with the beam and using the optics, visually check the focus and alignment. Then you move to the weld joint and st…

> Tungsten is the only metal you can reliably use as our machines have beam powers up to 15kW which can precisely deliver an enormous amount of heat into a pencil point sized area. Even at the common 1-3kW ranges the tungsten instantly liquefies when the beam turns on. I'm sorry - is there an error here? As I understand the rest of your comment, you use Tungsten because it does not liquify?

No error. The tungsten liquefies locally to the section of the block where the beam strikes but the surrounding tungsten stays solid. It's a poor heat conductor so it doesn't form a wide liquid puddle. With copper or aluminum the heat spreads rapidly and the pool grows wide very quickly.

Re: My Tungsten Cube (2019)

#336

Post by moftz » Mon, Aug 30, 2021, 5:43 PM UTC

anonporridge wrote: post #241

moftz wrote: post #218

Earlier quoted context omitted.

Gold can easily melt in a house fire. A diamond ring can turn into a puddle of gold and no diamond because it burned off

Melted gold is just as valuable as gold jewelry, since they melt it down anyway when you sell it. It might be worth marginally less than an intact piece of gold bullion that can be resold without processing. Diamonds don't have resale value anyway. They're literally a scam.

Diamonds do have significant markup depending on where it is purchased but they do still have some value. As long as the buyer can verify the certificate and the diamond is of significant quality, size, clarity, etc. it still retains value. A gemstone buyer may offer less than a private buyer (just like with cars) because they are in the business of selling the diamond later for a profit. Obviously, there is artificial inflation from the manufacturers but everyone else still has to play in the inflated market.

As for gold jewelry, this can swing both ways. An intricate piece with some sort of history attached may fetch a higher price from a buyer that is interested in that versus a scrap buyer that will just melt it down.

Similar analogies can be found with cars. A factory stock 1996 VW Golf will only be worth slightly higher than scrap value. Meanwhile, a 1996 VW Golf Harlequin will be worth $8-9k, its the same car but with a different factory paintjob. Effectively no difference in manufacturing costs since it was just made from different stock-painted panels but worth way more to a buyer simply due to the history and rarity. The cars both still have the same scrap value, a junkyard would buy both of them for the same price.