What is the worst metal for TC?

[bombastinator]

Question: what wire type is the MOST resistant to resistance change via heat? Is it ka1? Ni80? Something else?


Why I’m asking (and where you are more than free to stop caring if you did in the first place)

So I’m trying to find an alternative to exotic coils which use very large amounts of power and seem so far as I can tell use most of it heating air rather than juice.
I’ve been messing about with something called a “radiator” coil which seems to me to be variations on a really really long thin single wire coil.
The purpose of the excercise is to get something that is easier to make and more efficient than an exotic coil. The latest iteration is a 6+mm 9 wrap 28ga ka1 single coil. It more or less works. The problem I’m having is that even with Ka1 there is enough resistance change that the resistance sensor on my ageis legend keeps thinking I’ve put a new coil in. It’s annoying. I’m trying to find a way to reduce that so I’m wondering if Ni80 might be an improvement, if there is something even better, or if there is any other better way around my issue.

 

[greek mule]

The most resistant to resistance change wire is Kanthal.
Only 0.000002 Ohm change for every 1 °C
This TCR value refer to 1 Ohm coil.

 

[bombastinator]

The most resistant to resistance change wire is Kanthal.
Only 0.000002 Ohm change for every 1 °C

Dang it. I had hopes. Worse, that’s a lot of zeros. This implies that either the coil is getting really really hot, or I’ve screwed something else up too.

Perhaps the mod is being less than accurate in other ways. I am pushing the ohms up to higher than normal numbers. Something is going on anyway, and I’m definitely the weakest link in the chain.

 

[DaveP]

AFAIK, Kanthal is the most stable in resistance among commonly used coil wires.

I use SS316L for power and TC mode, but I'm more often in Power mode most of the time. It has a wide range of resistance and that's good for TC or Power and it switches back and forth well to either mode.

I've never ventured into exotic coils, so I'm probably not the guy to offer info here, but the post might alert others to enter the conversation.

These articles might be of help in choosing the safest wires for your particular vaping application. He talks about resistance change and stability when heated as well as allergies to various metals in vaping.
E-cigarette coils from a chemist's point of view
This one discusses vape wires for various applications.
Wound up about coils? Check out this handy guide! - Ashtray Blog

 

[greek mule]

The latest iteration is a 6+mm 9 wrap 28ga ka1 single coil.

This coil come out at 3.6 Ohm
TC precision: 0.000002 x 3.6 x 1.000.000 = 7.2
Perhaps this is why Aegis is asking for new/same coil.

 

[greek mule]

Aegis Legent's resistance range in power Mode is 0.05-3 Ω.
It doesn't accept this coil.

 

[zoiDman]

... The latest iteration is a 6+mm 9 wrap 28ga ka1 single coil. It more or less works. ...

6mm is just a Tad under 1/4".

That's a Big Coil.

 

[bombastinator]

This coil come out at 3.6 Ohm
TC precision: 0.000002 x 3.6 x 1.000.000 = 7.2
Perhaps this is why Aegis is asking for new/same coil.

I’m getting anywhere from just under 2 to just under 3ohm depending. The 6mm diameter was external of the coil when in place and the thing wasn’t exactly dead even. What I really need I think is a 4.5mm mandrel. Gotta start measuring my philips head screw drivers I guess.

 

[Punk In Drublic]

A 3ohm coil of that dimensions will require a load of voltage! ~10 volts for 35 watts. Fail to see what you are trying to accomplish here?

Assuming the coil’s resistance and requested power is within a comfortable medium for the device you are using, it’s resistance should not jump as indicated (if using SS, Kanthal or Ni80). If it does, this tells me there is either a problem with the build, or the device.

 

[bombastinator]

A 3ohm coil of that dimensions will require a load of voltage! ~10 volts for 35 watts. Fail to see what you are trying to accomplish here?

Assuming the coil’s resistance and requested power is within a comfortable medium for the device you are using, it’s resistance should not jump as indicated (if using SS, Kanthal or Ni80). If it does, this tells me there is either a problem with the build, or the device.

I was running it at 20w. Got a aromamizer plus on an ageis legend. Yeah, problem on the build or device sounds likely.

 

[bombastinator]

A 3ohm coil of that dimensions will require a load of voltage! ~10 volts for 35 watts. Fail to see what you are trying to accomplish here?

Assuming the coil’s resistance and requested power is within a comfortable medium for the device you are using, it’s resistance should not jump as indicated (if using SS, Kanthal or Ni80). If it does, this tells me there is either a problem with the build, or the device.

As to what I’m trying to do is I’m trying to make a flavor chaser DL build that will run on a non monster mod (such as the legend) Its not going super well. I got a new build now which is 2 x 10 wraps of 28ga on a 5mm mandrel coming in at .9ohm rising to ~1.2 or there about. Problem is I had to put the coils closer to the deck than I’d like to fit em and the airflow sucks so the flavor isn’t there. It’s running 5v @ 27.5w though, which is in range for most mods though. Now I just got to make it tasty.

 

[Punk In Drublic]

As to what I’m trying to do is I’m trying to make a flavor chaser DL build that will run on a non monster mod (such as the legend) Its not going super well. I got a new build now which is 2 x 10 wraps of 28ga on a 5mm mandrel coming in at .9ohm rising to ~1.2 or there about. Problem is I had to put the coils closer to the deck than I’d like to fit em and the airflow sucks so the flavor isn’t there. It’s running 5v @ 27.5w though, which is in range for most mods though. Now I just got to make it tasty.

Kanthal, even Ni80 should not rise that much – you have a problem with your build or device if either of those metals are rising in resistance by that amount.

 

[tdman77]

@bombastinator You should try mesh or flat wire. It can give you the size without the mass of regular round wire.

 

[bombastinator]

@bombastinator You should try mesh or flat wire. It can give you the size without the mass of regular round wire.

I got no atty capable of taking mesh atm. I do have some flat wire but the stuff is like tinsel. It’s too wide and not thick enough to form a coil with.

 

[bombastinator]

Kanthal, even Ni80 should not rise that much – you have a problem with your build or device if either of those metals are rising in resistance by that amount.

I suppose I can check across multiple mods. I’m also not getting much in the way of info from my DNA devices. I’m gonna have to bite the bullet and mess with the evolv software. I’ve been avioding that. The generic DNA250c GUI just isn’t giving me the info I need though I think.

 

[RayofLight62]

By considering the worst TC metal to be the one with lowest temperature coefficient, that is SS.
On the other hand, SS has an high overall resistance, which helps in saving battery power.

The best TC wire would be pure nickel, which has the highest TCR, about 600.

But a nickel coil can easily have a excessively low overall resistance, where the mods have an abysmal conversion efficiency, killing batteries altogether.

This is why I (and many others) use NiFe30 (or NiFethal) which has about half of the nickel coefficient, 320, but an overall resistance within the linear portion of the efficiency curve of most mods.

This NiFethal alloy is by far the most expensive TC wire (excluding Au and Pt) but has the added advantage of a TCR value certified and guaranteed by the manufacturer.

 

[Punk In Drublic]

By considering the worst TC metal to be the one with lowest temperature coefficient, that is SS.
On the other hand, SS has an high overall resistance, which helps in saving battery power.

The best TC wire would be pure nickel, which has the highest TCR, about 600.

But a nickel coil can easily have a excessively low overall resistance, where the mods have an abysmal conversion efficiency, killing batteries altogether.

This is why I (and many others) use NiFe30 (or NiFethal) which has about half of the nickel coefficient, 320, but an overall resistance within the linear portion of the efficiency curve of most mods.

This NiFethal alloy is by far the most expensive TC wire (excluding Au and Pt) but has the added advantage of a TCR value certified and guaranteed by the manufacturer.

And what is that abysmal conversion efficiency?

No denying the extremely low resistance of Nickel, but it is easy enough to build within a comfortable range.

 

[RayofLight62]

Not widely advertised, but cheap 200 W mods starts behaving bad below 0.2 Ohm coil resistance. The conversion efficiency rapidly departs from that ~90% to much lower value.
When that happen, the mod became warm, the batteries lasts much less than expected, or both.
The higher resistivity of Nifethal is just enough to bring up coil resistance that small amount, but enough for the mod to behave within reasonable numbers.
You can find the full explanation on Nifethal datasheet, as this type of wire was created on purpose for vaping.
I believe the £12 per roll to be the real obstacle to its wider diffusion, but once you try it, you don't go back to Nichel.

 

[Punk In Drublic]

Interesting. I own a about a dozen cheap 200 watt and less mods that I use with my most preferred atomizer set up of 0.13ohms and I have not experienced anything that you have mentioned regarding heat or even battery life. I have even objectively, if counting puffs is considered objective, measured battery life against atomizers that employ 0.4 to 0.5+ ohms that I also operate at the same wattage as my 0.13 ohms atty. And no differences were found. Of course, counting puffs is not a true representation of battery life, but think it is accurate enough to display any abysmal differences in efficiency

I am open to the efficiency of a regulated device not being a static figure through out the devices resistance range. But does it change so drastically that a resistance of <0.2 ohms warrants being rated as a battery killer? Sans a high power setting of course.

 

[bubba106]

I know this is late, but I thought you were not suppose to use kanthal for tc.