Standard & micro coil question

[Trayce]

On a standard coil if any of the wraps are touching one another, does that produce a hot leg that can scorch the post insulator and cause that awful taste? If not coils touching one another, what causes a hot leg in a standard coil?

Also, I heard on a micro-coil if any of the wraps aren't touching, that causes a hot leg. True or false?

Thanks much!

 

[notawoman]

On a standard coil you don't want any coils touching and you want to get the coil legs to be very close to the posts. If your legs are too far away part of your legs can glow as they aren't touching wick. I imagine if you let that go on long enough it would burn and taste horrible. Another problem I've had is when there are gaps between the coil and wick, sometimes it can be hard to spot. This can give off a bad taste. I get rid of this problem by firing while the coil is juiced up. If you fire for a little bit you can catch it glowing sometimes.

Microcoils are different, the coils need to be very close together to work right. You create a small oxidation layer when you fire them and it stops the coils from shorting on each other.

 

[Trayce]

On a standard coil you don't want any coils touching and you want to get the coil legs to be very close to the posts.

OK, now on my IGO-L dripper, I have actual posts... but on a standard RBA head there is only the center positive post. So are you saying the coil needs to be as "low" as possible in the cup? I lay a nail or drill bit across the wick divets so the coil is as low as it can be.

If your legs are too far away part of your legs can glow as they aren't touching wick. I imagine if you let that go on long enough it would burn and taste horrible. Another problem I've had is when there are gaps between the coil and wick, sometimes it can be hard to spot. This can give off a bad taste. I get rid of this problem by firing while the coil is juiced up. If you fire for a little bit you can catch it glowing sometimes.

Good to know... I use cotton wicks so that's never a problem, thankfully. They swell up nice and fat.

Microcoils are different, the coils need to be very close together to work right. You create a small oxidation layer when you fire them and it stops the coils from shorting on each other.

Interesting!

Well I built three new standard coils for 2 Aro tanks and a PT2 and all 3 hit great and were performing flawlessly... but then after vaping X-amount of time (hour for one, less for the others) they started giving me that horrid taste that comes from a hot leg 'burning' the positive post insulator in the bottom of the head. So wondered what I was doing wrong. I have been rebuilding coils about a month, and this is new. :-/

 

[spacenoob]

I want to see pictures! :]

For standard coils:
I noticed if I'm not careful while wrapping i'll get a hot leg. for example, if there's a weird bend or weak point in the wire. Also, the shorter the legs are the less likely they will get hot, but I prefer my coil to be as close to the air hole as possible and that sometimes means low and kinda far from the post (depending on what RBA you're using). just make sure the wires are tight and well wrapped and there shouldn't be a problem.

For micro coils, I've seen legs burn hot on the first and second pulse, but you MUST squeeze the coil with pliers/tweezers a few times to make sure theyre all touching and well-formed. Usually this fixes any hot spots and the coil will burn from the center -> outward.

of course my opinion is based on personal experience, so if you're using different guage wire or different wicks then this could all be different for you. I use 28ga kanthal with 3.5mm silica for standard and ~2mm cotton for micro coils. I'm guessing the thicker the wire, the longer the legs can be without forming hot spots, but don't quote me on that!

Good luck!

 

[vapdivrr]

on a device with a single pp and with standard wraps the glowing legs are for the most part caused by incorrect tension of the wraps. so if your first wrap, near the insulator, doesn't have the correct tension, it will cause a hot spot and hot leg causing this insulator to heat up. usually the aweful taste is not the actual insulator itself but just the excessive heat of the wrap that's not making good contact with the wick. as for the height of the coil, it really has to do with the position of the air hole in the device itself.

 

[Trayce]

Thanks guys for the excellent advice.

Here is a pic of one of the 3 standard coils I made yesterday [cotton wicking] that started tasting like a burning insulator after a short time of vaping...




Then I made 4 micro-coils with 30g kanthal wound around a small nail.... here's one:





Heated them up over the gas stove and compressed with tweezers. All came out to @ 2.6 ohms and fired perfectly. The one in the IGO-L dripper is fine and has ok flavor and great vapor. (I must be crazy but micro-coils seem to mute flavor to me.)

The other 3 coils (2 in Aro pyrex tanks, 1 in a PT2) had very muted flavor as compared to the standard cotton coils I've been using in them. So was bumping up the watts to find the sweet spot (Vamo 3), but as soon as I'd get near 7w where I could start to get even a little flavor (and actually needed to bump it up once more) they developed the same problem of tasting like the insulator is getting singed. Might be a "hot wire" taste as vapdivrr suggests, but it's nasty and not the taste of burnt juice. So I'm at a loss.

Comments? Suggestions? Thanks!

 

[Trayce]

on a device with a single pp and with standard wraps the glowing legs are for the most part caused by incorrect tension of the wraps. so if your first wrap, near the insulator, doesn't have the correct tension, it will cause a hot spot and hot leg causing this insulator to heat up. usually the aweful taste is not the actual insulator itself but just the excessive heat of the wrap that's not making good contact with the wick.[...]

So, in a standard RBA head are you saying that if there is too much tension on either leg that's fed through the bottom, that can cause it to heat up and taste bad? Cause now that I'm thinking, after I fed the legs through and inserted the insulator and positive pin, I think I used the needle nose to tug on each leg a bit before snipping them, just to make sure there was no 'slack' after shoving the grommet and pin in. (The wrap nail is still inserted through the coil so it stays where it should.) Maybe in tugging on the legs I weakened them...?