Boiling heat and spit backs issue Subtank Mini

[Syakster]

Hey everyone,

Just thought someone here could help me out on an issue I encountered today with my Subtank mini (which has been working fine for me over the past month).

Yesterday I decided to try and build my own coil, using a 26g kanthal. I did 6 wraps around the screw diver that came with the Subtank and it came to 0.5ohm.

It all seemed fine, but now when I vape, it gets VERY hot. The drip tip burns my mouth, and on top of that I have juice spewing into my mouth too.

I figured it could be flooding, so I cleaned everything up and rewicked the thing the way I always did. Same issue persist.

I usually vape at about 20w, so this time I went to as low as 8w and it's still boiling hot. What's going on?!

What am I doing wrong?

 

[Rixsta]

Hey everyone,

Just thought someone here could help me out on an issue I encountered today with my Subtank mini (which has been working fine for me over the past month).

Yesterday I decided to try and build my own coil, using a 26g kanthal. I did 6 wraps around the screw diver that came with the Subtank and it came to 0.5ohm.

It all seemed fine, but now when I vape, it gets VERY hot. The drip tip burns my mouth, and on top of that I have juice spewing into my mouth too.

I figured it could be flooding, so I cleaned everything up and rewicked the thing the way I always did. Same issue persist.

I usually vape at about 20w, so this time I went to as low as 8w and it's still boiling hot. What's going on?!

What am I doing wrong?

More wraps will mean cooler, less wraps will be hotter. Also thicker wire or thicker wraps will also make a cooler coil.

In saying that, 26g should be fine at 0.5ohm, well done in getting 0.5ohm in the first place. Could do with an expert here as I'm def not going to be much help I feel.
Do you vape with full air flow open and lung hit, that could also be a factor, as for the juice in the mouth, yup, the coil has flooded, maybe try a little more cotton next time..
I'm sure the coil wizards on here will help you out, good luck on your build.
Maybe try one more wrap ?

 

[Nikea Tiber]

Did you test fire your coil before you wicked and installed it? I feel that while people successfully build around the ubiquitous blue handled screwdriver it results in too small of an inner diameter coil to wick efficiently enough to supply enough juice to dissipate hotspots in the coil (though I freely admit that I haven't experimented much with microcoils).
The subtank rba has got a pretty tiny chamber so it can be a challenge to get good clearance for coil spit dissipation. Make sure the coil is centered over the airflow hole so one side of the coil isn't getting hotter than the other.

 

[yuseffuhler]

I'd also like to throw out the possibility of hot legs. That might cause some issues.

 

[dhood]

You have to be real careful with trimming the legs on the coils. They can't extend beyond the screws at all or they can touch the chimney and short out.

 

[Syakster]

You have to be real careful with trimming the legs on the coils. They can't extend beyond the screws at all or they can touch the chimney and short out.

I've discovered that this was in fact the problem. I clipped them with some nail clippers, but apparently not good enough. I built a new coil and used the hand trick or whatever it's called when you just twist the wire until it snaps off. Works much better.

 

[Syakster]

I'd also like to throw out the possibility of hot legs. That might cause some issues.

I think this was the issue. I checked the coil as soon as I got home and I noticed a teeny tiny bit of excess leg. Built myself a new coil and made sure to really trim it completely and now it's good again.

 

[suprtrkr]

That was going to be my suggestion too. Glad you found it and it's now working. I would suggest a larger diameter coil, though. I have better luck in the 2-3mm range. Might want to try rayon wick, too.

 

[yuseffuhler]

I think this was the issue. I checked the coil as soon as I got home and I noticed a teeny tiny bit of excess leg. Built myself a new coil and made sure to really trim it completely and now it's good again.

If you're using the rebuildable section, put a little power to the coil and check and make sure it glows evenly and doesn't have any jot spots or hot legs. They cause a lot of problems. In my RBA of my subtank, I normally use around 3 mm coils. It holds more wick and doesn't dry bit as long as it's wicked right.

 

[LewAz]

In my RBA of my subtank, I normally use around 3 mm coils

I use 3mm id coils as well.

 

[dcfluegel]

I've discovered that this was in fact the problem. I clipped them with some nail clippers, but apparently not good enough. I built a new coil and used the hand trick or whatever it's called when you just twist the wire until it snaps off. Works much better.

when putting a coil on that rba, after i install, i now usually loosen screws, slide coil to one side, trim a little extra, slide to other side, trim a little extra then center and re-tighten - have not had any shorting issues since

 

[orbit.al]

when putting a coil on that rba, after i install, i now usually loosen screws, slide coil to one side, trim a little extra, slide to other side, trim a little extra then center and re-tighten - have not had any shorting issues since

Great hint, will do that on my next coil.

 

[RandyF]

What device are you using? If your coil is .5Ω then 20 watts is too low for a device without step down. I'm going to guess you are since you said you lowered it to 8 watts and it was still hot, an iStick perhaps?

I don't think it was a leg touching the chimney, that would have shorted (snapped) the coil, at the very least the resistance would have been all over the place.

 

[dcfluegel]

Great hint, will do that on my next coil.

also, just a heads up - you can purchase a 20 pack of pre-coiled .5ohm coils (usually packaged with a couple pads of cotton) for under $10 bucks from several online vendors - Kanger Subtank Pre-built RBA Coils (20-pack) - 0.5 ohm or 1.0 ohm | SmokTek.com