Do coils go bad?

[cjpeltz]

I do like to build coils, but once in a while I hit on a great coil build that I want to keep for an extended period of time. Assuming the leads do not break and the coil itself retains form, is there any other reason to replace it after so many days or weeks? Of course, outside of wanting to tinker and put in a new coil for the heck of it -- just trying to understand if coils themselves start to degrade in performance over time.

Thanks!

 

[Jimi D.]

They do lose their resistance in time. I change mine before that happens. I just like clean vapor all the time.

 

[flog]

Is it due to the thermal expansion/contraction or crystalline shifts? The most mine have lasted were a week, but that's due to wanting to try some other builds. Should get some more drippers, cheap & good ones.

 

[Dampmaskin]

That, and oxidation. Kanthal rusts. Other materials oxidize too.

 

[Stringplucker]

I change wicks often, but I'm still working on the same set of coils in my Tobh that I put on 2 months ago...and I hit it hard everyday. 24ga, dual parallel wrapped to 0.15 ohm vaped on 32A 26650 Efest batteries. I have yet to register a noticeable degradation in ohm or vape. I guess changing the wick often helps...and cleaning them with a small stainless steel bottle brush every couple of days, too. Rinse in water, then in Everclear, burn them off, then brush...keeps them in good working order.

If I want to play around with other wraps, I have other RDAs to use...but the Tobh and the coils on it are a constant.

 

[State O' Flux]

-- just trying to understand if coils themselves start to degrade in performance over time.

Thanks!

Kanthal does 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 and anti-corrosive 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.

 

[twall]

I like your toubillion avitar, State O' Flux.

Thanks for asking this; I wondered myself. The coils in my Vulcan are a month old.