Strange Kanthal corrosion

[Smokyg]

I have been noticing my kanthal doing this weird blue corrosion even when just firing it before it has seen any juice, and after a weeks vaping and then a dry burn the blue comes back and those blue pieces falls off causing the coil wires to thin out and creating serious hotspots.

Im getting quite concerned. Might the Kanthal be of lower grade?

Below is a pic of a coil i just rolled and fired. It hasn't seen any juice yet.

 

[annemarievdh]

That's weard!!!

 

[RevnLucky7]

I've seen that before...
Looks like death.
Read any Discworld novels?

Sure that's Kanthal? Or Kanthrax?

 

[Andre]

Have never seen anything like that before. Cannot be healthy. Where did you get the wire from?

 

[Smokyg]

Have never seen anything like that before. Cannot be healthy. Where did you get the wire from?

Won it at the jhb vape meet.

Perhaps im firing it to hot so it starts to oxidise?

 

[Smokyg]

Won it at the jhb vape meet.

Perhaps im firing it to hot so it starts to oxidise?

Im not really a expert in metals and how they react to heat, but i cant really find anything on the web about kanthal oxidising or corroding.. This is super weird.

 

[Danny]

I would stop vaping on that. Kanthal from my limited understanding should really not deteriorate rapidly at all used in our applications. An idea of how tough the stuff should be.... It has a melting point of 1200 degrees centigrade! I have wrapped quite a few coils and ran a few for well over a month. I chucked them but they still looked like they did when I wrapped them, only thing that changed was they seemed to lose heat capacity.

 

[Smokyg]

I would stop vaping on that. Kanthal from my limited understanding should really not deteriorate rapidly at all used in our applications. An idea of how tough the stuff should be.... It has a melting point of 1200 degrees centigrade! I have wrapped quite a few coils and ran a few for well over a month. I chucked them but they still looked like they did when I wrapped them, only thing that changed was they seemed to lose heat capacity.

I have had no issues with my kanthal up until now. Im going to try a few tests to see if it is the extreme heat of the 0.2 ohm coil thats causing the rapid degradation of the wire.

This didnt seem to happen with colder coils. So my conclusion thus far Extreme Heat = Nasty blue stuff.

 

[Danny]

I have had no issues with my kanthal up until now. Im going to try a few tests to see if it is the extreme heat of the 0.2 ohm coil thats causing the rapid degradation of the wire.

This didnt seem to happen with colder coils. So my conclusion thus far Extreme Heat = Nasty blue stuff.

You should experiment if you think it will help. Kanthal does form aluminum oxide on its exterior when heated. It should not deteriorate as you have described as a result of this though. I dont think even a 0.2 ohm coil is going to produce enough heat to significantly impact the overall structural integrity of a substance like Kanthal. Maybe a physics/chem person will have some input.

 

[Rowan Francis]

that blue corosion looks like a copper deposit , check to see if there is any copper in contact with the kanthal . ie . something that is copper and was plated but now the copper has come thru and is touching the kanthal , like screws or posts .

 

[Derick]

From what I've read, Kanthal will only start to oxidize at very, very high temperatures - i.e 1300C
http://kanthal.com/en/products/material-datasheets/wire/na/kanthal-apmt/ (search for "flake")

I doubt you are getting to those temps with your setup, seeing as VG and PG only need around 200C - 300C to vapourise, at 1300C you would be burning it and it would taste like crap (i.e. you would be creating acrolein , not PG and VG vapour)

 

[Smokyg]

that blue corosion looks like a copper deposit , check to see if there is any copper in contact with the kanthal . ie . something that is copper and was plated but now the copper has come thru and is touching the kanthal , like screws or posts .

That sounds like a reasonable explanation. My igo l consists of brass posts and i replaced the screws with bigger headed stainless screws.
No copper anywhere close sadly.

 

[Rowan Francis]

That sounds like a reasonable explanation. My igo l consists of brass posts and i replaced the screws with bigger headed stainless screws.
No copper anywhere close sadly.

maybe , but i would say maybe the washers or something else has copper somewhere , the stainless srews might have plating on them ?? file one and check .

 

[Andre]

Best I could find on ECF

Yep... Kanthal wears out. When heated, Kanthal wire (iron-chromium-aluminum) builds up an aluminum oxide thermally conductive coating on it's outside surface that protects the individual coils from shorting, one to another. This is called alumina (Al2O3).
Once the aluminum content diminishes to the point where that oxidation resistant, electrically resistive alumina layer isn't produced... all that remains is iron and chromium oxide.
Exposure & contamination degradation, inconsistent heating, increased resistance and ultimate wire failure aren't far behind. Chances are, you'll see the blackened, pitted wire or perhaps even taste the iron, long before that failure occurs.
http://www.e-cigarette-forum.com/fo...4216-question-about-kanthal.html#post13700531
EDIT: But I do not think that is what is happening here. Maybe that is not good Kanthal wire.

 

[Matt]

I had the same with the kanthal I bought from vapemob. Used different kanthal in the same setup and it didnt happen again.

 

[Imthiaz Khan]

@Smokyg, hope you get this issue sorted out asap! Vape safe bud

 

[Smokyg]

I had the same with the kanthal I bought from vapemob. Used different kanthal in the same setup and it didnt happen again.

Thanks! Yeah i think that maybe they have been supplied a lower grade kanthal, perhaps D. I know when i enquired from a bulk importer, thay told me that they only supply Kanthal D. Perhaps this has now trickled down to us. Either way, we should insist on A1 only.

 

[Danny]

I did a bit more reading, also came across this thread where some people are discussing what happens to kanthal over time (http://www.e-cigarette-forum.com/fo...thal-over-time-intense-heat-production-2.html) not all of it relevant but they surmise it quite nicely.
The alumina (oxide of aluminium) that forms on kanthal when we heat it is what allows us to build contact coils without shorts Eventually the oxidating process would cause your kanthal coil to degenerate, but not that quickly, for 28g and below I would guesstimate weeks to months. Definitely not on first fire.

 

[RevnLucky7]

Boet, only test you should be doing with that wire is how fast you can get all of it in a bin. Whatever is happening there does not look good and most importantly not healthy.

I wouldn't even bother putting it through tests...

I run Kanthal as hot as any device allows me too and I've never seen that before.

Sent from my SM-G900H using Tapatalk

 

[TylerD]

Not cool man. Just get some net wire man. So sad that we get these sub par stuff here! Batteries and now bloody Kanthal. What's next!

 

[ET]

could just be one small section of faulty wire. make another coil exactly the same and see if it still does it

 

[Gizmo]

I highly doubt its bad kanthal. Kanthal is kanthal in my opinion. I haven't had that happen to me but I am sure its related to the atty itself and the kanthal, like Rowan said.

Assuming, If you could get kanthal of such a poor grade, then every single cheap toaster would have little particles of metal on your bread.

 

[Smokyg]

Just built a new coil and dry fired it a few times and al presto.

 

[Alex]

Just built a new coil and dry fired it a few times and al presto.

The only thing I can think to ask is this: Where are you storing the Kanthal?

 

[Smokyg]

The only thing I can think to ask is this: Where are you storing the Kanthal?

In my desk drawer together with my screw drivers and coil wrapping tools.