While doing a routine dry burn on a week old, 28ga 7 wrap micro, it suddlenly "went yellow". I put the tester on it and it read .2! This was a .6 coil before. Connections were all tight. There was the appearance of a stripe running perpendicular to the coils. Is it possible to fuse kanthal at normal operating temps? I pulled it immediately, and my spring had not weakend or collapsed. This is new to me, I have not seen this in hundreds of coils. Engineers, any ideas? I just want to be safe about things, and the idea of suddenly running a .2 ohm coil gives me the heebies.
Fused microcoil?
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I'm no engineer but did anything change recently? Juice? Something lowered the resistance of that coil.... Any chance of a tailing dropping out of the cap of the atty and laying across the coil just right?
Glad you caught it while doing a dry burn instead of vaping on it. I'll be following this thread.
Edit: might as well ask as someone else will if I don't. What kind of atty were you running? What's it made of. How old was the coil?
Glad you caught it while doing a dry burn instead of vaping on it. I'll be following this thread.
Edit: might as well ask as someone else will if I don't. What kind of atty were you running? What's it made of. How old was the coil?
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If it's Kanthal... the only way it can fuse is if the alumina (aluminum oxide layer that provides an electrically resistive exterior surface) content is completely exhausted... exposing the remaining iron and chromium.
This occurs over an extended period of time - if the coil is dry burned regularly - or sooner, if the coil is dry burned frequently / excessively.
it was an act of god you should have vaped it would have grown angel wings and saved the world from these glutonous putrid money clenching politicians that abuse democracy for they know not what they do lord or do they
That is interesting... I dry burn my coils and quench under running water while almost glowing, this strips the crud from the wire to reveal fresh grey kanthal. But after a long time the color changes to dark brownish, I wonder if that's getting close to end of life for the coil. I wondered about the color change, maybe its the alumina leaving the skin?
Sloth, that Wakonda juice is getting to you
or did you find a new natural flavoring agent on one of your wanderings in the jungle?
i have not been to the jungle yet want to go chrissy my parttner spent a year in guatemala there she traversed the jungles and mutant monkeys and spiders within but thus far i have only traversed mountains and forests of which some resemble well one in particular resembles the forest that Yoda lives in i actually lived in that forest for 4 months while working on trails i lived with yoda
Oh, They Know - Thats why they went into politics
Its just become so damn obvious
And they know the voters really don't want to know
Question: What are the voters going to do about it?
Answer: Just keep switching parties...
It takes the voters 8 years to figure out that they need to switch parties again
By then they are all filthy rich from stealing everything they can get their hands on for 8 years
The voters just don't want to know that nether party is worth voting for
Which means: Any Republican that runs is going to be the next President of the USA
And this guy is going to leave this country in even worst shape then the last guy did
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Although I can't speak to your particular cleaning method as one that is more or less aggressive, vs. say, a dry burn and light brushing, yes... you are correct. With Kanthal A1, the aluminum content is vaporized... primarily from dry burns (and to a far lesser degree from firing a coil with dry wicking). I suppose aggressive metal brushing can wear off the alumina as well... although, aluminum oxide is pretty tough stuff.
If we could keep coils clean without aggressive methods like dry burning, I suspect they might last significantly longer. Colorants, flavorings, sweeteners and high VG juices in general however, conspire against keeping coils caramelization/sediment free. ;-)
When the aluminum is near gone, you'll see inconsistencies in the coloration of the wire. The iron content shows as darker "freckles" in the lighter silver/grey aluminum. Continue on, and the wire will, depending on your methods of cleaning, show as a near solid brown to black coloration... and indication that all which remains is iron and chromium. All this can be seen with the naked eye... or if you're blind like me, though a 5-10X loupe.
You may also find inconsistencies in resistance as well. Compressed (aka "micro) coils, without the alumina insulation, have the potential to short out, indicated by a lower than original resistance. Interestingly enough, it can also increase in resistance as the wires conductivity decreases from a loss of cross-sectional area... so you may not see any change in resistance.
I'm not so sure about that idea of dry burning and then shocking the wire by exposing it to water while still hot. I know what that can do to aluminum or stainless cookware, I can't imagine it's a good idea for kanthal.
Hard to say, Rick. One would have to do quite a bit of research to get a good grasp of the effects of, what amounts to quench hardening on, otherwise annealed, Kanthal alloy.
Could lead to micro-fractures (and resistance changes that might accompany them), an undetermined effect on the intended metallurgical "performance" at normal operating temperatures, premature wear or, from the pro side of things... perhaps even extended life span of the coil.
Off the top of my head... I see a possibility for ......ing the formation of an alumina layer - but that's just a guess at this point. A few folks at Temco could probably tell us, but the last time I contacted them requesting technical information, I got a salesman instead of an engineer.
Hard to say, Rick. One would have to do quite a bit of research to get a good grasp of the effects of, what amounts to quench hardening on, otherwise annealed, Kanthal alloy.
Could lead to micro-fractures (and resistance changes that might accompany them), an undetermined effect on the intended metallurgical "performance" at normal operating temperatures, premature wear or, from the pro side of things... perhaps even extended life span of the coil.
Off the top of my head... I see a possibility for ......ing the formation of an alumina layer - but that's just a guess at this point. A few folks at Temco could probably tell us, but the last time I contacted them requesting technical information, I got a salesman instead of an engineer.
Googling this subject just made my head hurt. Not the actual googling.
Snoop says...
"Kanthal" + "quench hardening" will make your head hurt. Don't do it.
;-)
Try "kanthal wire response to thermal shock" - go ahead, you do it.
Interesting. I was most intrigued by...
Poisson's ratio 0.3 (0.25..0.35) 0.25 (0.2..0.3) 0.4 (0.3..0.5)
... for each of metals, ceramics, and polymers, respectively.
aaaaand I'm going to lie down now.
curse you, Rick. I just had to look.
That is an extremely interesting and informative post, thank you!
I actually quench my microcoils while still glowing red, but with the fire button released just before quenching. Because I vape a mix of NET's and 50/50 PG/VG unflavored the coils can get a good crust on them after about 12ml of juice, and I have found this method does clean them effectively and quickly, usually 2 quenchings is sufficient to make them look like new, otherwise its 3. I am using 9 wraps of 30 gauge A1 on a 1/16" former, 1.9 ohms, on a mech (Reo). My previous method to clean the coil was to dry burn once, then run a 1/16" drill bit through the middle, and then use a tiny nylon brush through the middle and on the outside, which also worked well, but that method took more time. I haven't noticed any longer life from either method, and have always changed out the coils when they darken simply because of the bad visual look, it just doesn't "look right".
So....is it bad to dry burn your coils then run under the sink for a few seconds? Been doing that for years now....
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