Coils. What's safe and what's not?

[Crewella]

Interesting thread, thank you. And I now want gold coils ........ and a gold spoon!

I'm ashamed to say that I've been making coils for over a year, but still don't really know why we 'pulse' so carefully when first heating a coil and then when dry burning. I get that you need to break a new coil in carefully, but beyond that it all gets a bit hazy. Help please ...... anyone?

 

[Badboybez]

Interesting thread, thank you. And I now want gold coils ........ and a gold spoon!

I'm ashamed to say that I've been making coils for over a year, but still don't really know why we 'pulse' so carefully when first heating a coil and then when dry burning. I get that you need to break a new coil in carefully, but beyond that it all gets a bit hazy. Help please ...... anyone?

Well "tubby" is the expert here.
The only thing I can relate it to is one of the things I have to do at work as a test engineer / installation engineer.
Our heaters in the reactors are basically the equivalent of huge atty coils.
They are mostly tungsten, and designed to go to 1450 C, but with a brand new heater we have to do a 2 hour low temp bake at 400 C
If we don't the tungsten will go brittle at the high temperatures, badly limiting it's lifespan.

 

[Crewella]

Well "tubby" is the expert here.
The only thing I can relate it to is one of the things I have to do at work as a test engineer / installation engineer.
Our heaters in the reactors are basically the equivalent of huge atty coils.
They are mostly tungsten, and designed to go to 1450 C, but with a brand new heater we have to do a 2 hour low temp bake at 400 C
If we don't the tungsten will go brittle at the high temperatures, badly limiting it's lifespan.

Thanks, yep that's about where logic was taking me too. I've also had thin wires (I'm a MTL vaper and rarely use thicker wire that 28 AWG kanthal) burn out on me and break if over-heated, usually when struggling with hotspots on a mesh build. I'm just not sure if it's as simple as that ..... hence the question.

 

[Maniac]

Seen a thing few years back with spoons made of different metals all used in the same yoghurt. The flavours were different for the different metals. As far as i remember the gold spoon had the best flavour. Cant remember other metals that were used. But interesting @Arctic_Wolf and others saying that stainless gives a crisper flavour.
Gonna try n find n post the vid.

Well, gold can be used only in TC so "no" is my only option (also because it would be frikkin' expensive)

 

[Crewella]

@Tubbyengineer would indeed be the ideal person to explain it properly ......... if you don't mind, please?

 

[Tubbyengineer]

Yep, It's mostly about evening out any flaws in the wire by heating slowly - When you work the wire you cause minor kinks, cracks and high resistance areas. Slowly heating the wire allows these to even out - it's pretty much the process of annealing, it lets the atoms move in the crystalline lattice and reduces the number of dislocations between them.

 

[Soutie]

on the commercial coil front, It is also woth while mentioning the doubt over the saftey of Ceramic coils. There was quite a stink a few months ago when Uwell did a study on these coils and had concerns on particals possibly breaking off and being inhaled.

I dont recall seeing a definitive outcome though.

 

[tasteslikefire]

Yep, It's mostly about evening out any flaws in the wire by heating slowly - When you work the wire you cause minor kinks, cracks and high resistance areas. Slowly heating the wire allows these to even out - it's pretty much the process of annealing, it lets the atoms move in the crystalline lattice and reduces the number of dislocations between them.

Something else I didn't know. So (in theory) if you 'cure' the wire for a while at low temp rather than just hitting it until it looks even regardless of settings you'll get a better result overall?

 

[Tubbyengineer]

Something else I didn't know. So (in theory) if you 'cure' the wire for a while at low temp rather than just hitting it until it looks even regardless of settings you'll get a better result overall?

Annealing requires the metal to be heated untill it starts to glow, then cooled slowly - so basically get the wire hot then let it cool without running it under the tap. This probably explains why I've NEVER had a TC wire break in use - I always heat them slowly at low wattage until I see the first sign of them glowing then let them cool, I'll then check to be sure none of the wraps are touching and that theres no hotspots by repeating the process - sometimes you'll need to cure a hotspot first time around but I do it two or three times in total...

 

[Crewella]

Very helpful, explained exactly - thank you @Tubbyengineer