Cause of spitting and popping in RDA's?

[Rangertrix]

So I just built my first twisted dual coil setup yesterday and I find that it spits juice pretty violently on initial firing. My other micro coil builds didn't do that. Is this normal with rda's? Is it a wicking issue? Thought maybe it was too much liquid but it does it less when I have freshly dripped liquid into it. Should I try folding wick over top of coils?
Sorry for RDA noob question, lol.
Any help would be greatly appreciated.
Thanks.

 

[Dampmaskin]

My guess: Not enough cotton. Empty space(s) between wick and coil causes the liquid to overheat.

 

[chapeltown]

Hey Ranger,

I have found that with RDA's, your wick can make the juice do some pretty funky things. I use cotton in my builds, and have found that there has to be just the right amount of cotton inside the coil for it to behave properly. Too much and you get a lot of popping, too little, and it does other things. The cotton when dry should slide fairly easily side to side inside the coil but not be loose either.

What is your ohm's to voltage/wattage? That could certainly affect things as well.

 

[Rangertrix]

Hey Ranger,

I have found that with RDA's, your wick can make the juice do some pretty funky things. I use cotton in my builds, and have found that there has to be just the right amount of cotton inside the coil for it to behave properly. Too much and you get a lot of popping, too little, and it does other things. The cotton when dry should slide fairly easily side to side inside the coil but not be loose either.

What is your ohm's to voltage/wattage? That could certainly affect things as well.

I am running it on a Magneto mech. It is .45ohm. I am using cotton. I've never had any issues when using cotton in my Russian's, but this is my first twisted wire build.

 

[Rangertrix]

Ok, update....I rewicked and it's not popping like it was. Not entirely sure if I used more or less this time, lol. Difference was minimal.
I did have to cut one end of previous wick to remove it. Of course the new cotton wick hasn't had enough time to expand, I don't think.
How long does it take for cotton to reach maximum expansion after being saturated?
When I went to dry burn before rewicking I did notice that my battery was awful low. The vape hadn't really changed any, but it was lower than I have ever run one before.
Kinda new to the mech thing.
Had been changing batteries often and finding that I hadn't hardly discharged them. Went longer before changing it this time.....too long.
Gotten to accustomed to my Provari's I guess.
Maybe battery was too low to properly vaporize the liquid?
If so, I've never experienced that before (of course only used regulated until now), but it makes complete sense.
Just not sure if it was the new wick or the new battery that has fixed it.
Not sure I want to run a battery that low again to test. It was at 3.02 volts, lol.

 

[Kemosabe]

youll get a better feeling of when your battery is at or around 50% the more you use your mech. 50% is the best time to recharge a li-ion cell btw (3.7v).

the spitting and popping is a sign of a less-than-perfect build, but i do not consider it problematic. i had a ribbon wire build that would give a loud, violent pop every time i fired it from a period of inactivity. it was enough to startle ya. i have other attys that are silent as hell. and others with a slight sizzle. none of them perform badly, its just something weird that happens with the juice/wick/coil perfect storm. i think it could be from cooled juice on the coils that gets shocked into vaporization. this is opposed to juice slowly getting drawn from the wick. this is just a guess, in all reality i dont know what the popping is. there are many theories on what it could be.

 

[Rangertrix]

youll get a better feeling of when your battery is at or around 50% the more you use your mech. 50% is the best time to recharge a li-ion cell btw (3.7v).

the spitting and popping is a sign of a less-than-perfect build, but i do not consider it problematic. i had a ribbon wire build that would give a loud, violent pop every time i fired it from a period of inactivity. it was enough to startle ya. i have other attys that are silent as hell. and others with a slight sizzle. none of them perform badly, its just something weird that happens with the juice/wick/coil perfect storm. i think it could be from cooled juice on the coils that gets shocked into vaporization. this is opposed to juice slowly getting drawn from the wick. this is just a guess, in all reality i dont know what the popping is. there are many theories on what it could be.

Yeah, I searched and found nothing definitive about it. It's back to popping, but only after a couple of draws. Doesn't do it when freshly juiced. Vapes nicely though. Tried re compressing coils and such to no avail. They glow evenly, from inside out, in sync, and look awfully pretty .
Just learned not to put to my face before I press button, lol.
I also searched and found no definite answer to what benefits there are to twisted coils versus a standard coil, other than like my case.....I had nothing but 30g and wanted something comparable to 28g.
Some say they retain more liquid, some say more surface area, etc......

 

[Rangertrix]

It is kinda cool though! When I first hit the button it makes two pops and throws two perfect little smoke rings out of the drip tip then settles in.
Maybe I'm overlooking the chance to be able to say "hey guys, check this out!"
This could be annoying AND fun, all at the same time!

Thanks for all the great advice guys.
I honestly think it has something to do with , as mentioned, inactivity; and just the right mixture of liquid and oxygen in between the twisted wraps when heat is applied. Because, as I said, when freshly juiced and coated it doesn't do this.

And I can't get the picture of Kemosabe trying to stealth vape when a really loud "POP" goes off out of head, lol . Can you imagine a dark, quiet movie theater, a loud pop, then a bright scene on the screen and everyone sees a huge cloud in the air! Then Kemosabe looks around, with his head on a swivel like it wasn't him with a "deer in the headlight" look on his face!
I only say this cause something similar has happened to me......minus the "pop".
Been there, done that.
And I'm rudely assuming your a him . If wrong, I apologize in advance .
Oh, the trials and tribulations of vaping!

 

[Rangertrix]

Another update.....out of curiosity I rebuilt my Russian 91% with a twisted coil and it does the same pop and spit upon initial firing.
I really think, in my case anyway, that the spitting and popping is caused by the twisted coil itself. Exactly what or why I don't know.

 

[Ease]

Another update.....out of curiosity I rebuilt my Russian 91% with a twisted coil and it does the same pop and spit upon initial firing.
I really think, in my case anyway, that the spitting and popping is caused by the twisted coil itself. Exactly what or why I don't know.

I have the same issue with twisted wire, too much popping. Does it every time, I've tried different diameters and gauges, more and less wraps. I just stick to regular microcoils, smooth as silk.

 

[HazMatt]

I think the popping is from e-liquid, that is on the coil, being heated faster than it can vaporize. On the initial firing, the liquid is at room temperature and the coils heat up faster than the liquid. Once the initial firing is over, the e-liquid that remains has been "preheated" and vaporizes more easily thus, reducing the chance of popping.

I have experienced popping on simple micro coils. However, it does seem to happen more frequently with twisted coils. This leads me to believe that twisted coils hold more liquid than normal coils.

Having read all of that, no matter how believable it may sound, please keep one thing in mind...I am in no way an expert in vapor dynamics. I am merely a dude on a mission. A mission to find my perfect vape.

 

[Rangertrix]

I have the same issue with twisted wire, too much popping. Does it every time, I've tried different diameters and gauges, more and less wraps. I just stick to regular microcoils, smooth as silk.

Yeah, I have tried 3 different devices and variations of coils. Twisted micros and regular micros. Same impedance on each.
I only experience the "pop" with twisted coils.
I think liquid must get trapped between the twists, and when heat is applied, it begins to thin and move. Having no where to go, because of the "dam" created by the twist, it begins to vaporize until the last minuscule bit vaporizes violently; causing the pop and spitting any residual liquid upward. The only direction it can go.
This is only my hypothesis. I'm not an engineer, and it's been a long time since I've had a fluid dynamics class, lol.
If any engineers read this post, be gentle, lol; but I would love to hear an engineers take on all of this.

 

[dgarci]

here's my take on it..

you're popping and spitting more on your twisted coils because of the juice that's on the surface area of your coiL.. so when your coil heats up, the accumuLated amount of liquid from your coiL, and how quickLy its repLaced by your wicking setup causes the initiaL pops..

when the accumuLated juice on the coiLs is vaporized, end of the popping.. and you get a smooth vape provided your wick is wicking exactLy the amount of Liquid, that your coiL vaporizes as it heats up..

if your coiL/wick is stiLL popping and spitting even after your initiaL firing, then your wick maybe wicking too much Liquid, too fast for your coiL to vaporize it.. (happened a Lot to me when using my fogger , because everytime I fire it, it wont ever run out of Liquid..weLL untiL my tank empties out.)

from there, it's just a matter of having the right amount of wick, for the type of coiL.. (twisted, micro,macro, whatever coiL.)

yeah, 2cents of mine.

 

[JD1]

Try a parallel wrap. Just fold the wire in half and wrap both ends side by side. I used to wrap 32 gauge to around 1.3 ohms with no poping, and decent heat up time.

 

[Firecrow]

I've been experimenting with rebuilding my Russian 91% (authentic) and I tried going with less cotton on a single coil of two strand twisted 28g kathal. I've rewicked this coil after 3 weeks of use for the third time. In this instance I cut it just above the stack and pushed the two cotton ends down towards the drawing holes. I also used less cotton in general, I didn't have trouble feeding the twisted cotton through the coil.

This is the first time I've gotten the popping sound - very loud too. The two prior builds did not have it. I conclude that its a result of less wicking surface and perhaps less direct cotton contact with the coil. The juice is sitting on the coil when I fire it rather than the cotton being up against the coil under pressure. There is also less cotton overall in the chamber, so there is less to dampen the juice-heat reaction.

I did this build about 10 minutes ago. Problem is I refilled the tank and I already lost juice rewicking, so I am reluctant to rebuild it again just to get rid of the popping by adding more cotton. I'm going to vape it for a while and see if it goes away as the wick breaks in and expands and some carbon builds up on the coil - or I run out of juice, whichever comes first.

I find the popping violent (0.7ohm on a 7-22) and it disturbs my peace, I like a quiet vape, so its not something I will want to live with for very long. But its was a good experiment in figuring out how much cotton to use. I think I found the lower limit.

It hasn't affected the quality of the vape, so again, I am reluctant to go digging into the new build as I am enjoying a freshly rewicked coil. I'll report back here on how it goes as the group here seems interested in getting to the bottom of this issue.

For those getting this frequently I would advise using more cotton and twisting it tighter so its snug against the inside of the coil.

 

[Firecrow]

WOW. My 7-22 just blew up!

After a loud pop and and electronic smell, smoke came from the firing button and the check battery light when on. The screen works okay but now the unit does not fire. I doubt its the builds fault (I can't see how that would cause it to happen. Bloody wild.

 

[Ryedan]

WOW. My 7-22 just blew up!

After a loud pop and and electronic smell, smoke came from the firing button and the check battery light when on. The screen works okay but now the unit does not fire. I doubt its the builds fault (I can't see how that would cause it to happen. Bloody wild.

Sounds to me like that puppy is toast Firecrow . Something fried. They say you can go down to 0.5 ohms, so 0.7 ohms should not have done it and the chip should have protected itself in any case.

I don't have one so I don't know if they have a warranty. If it's in a warranty period you should be able to get a replacement.

Good luck with it!

 

[edyle]

WOW. My 7-22 just blew up!

After a loud pop and and electronic smell, smoke came from the firing button and the check battery light when on. The screen works okay but now the unit does not fire. I doubt its the builds fault (I can't see how that would cause it to happen. Bloody wild.

sounds like the battery vented.

what kind of batt?

 

[Firecrow]

Wasn't a battery vent, its fine. It was the electronics for sure. The unit did its job from that point of view - I think its unrelated, the coil is well within the specifications that the 7-22 is designed to fire and to protect you from failures that result in a battery vent (don't want this to be fodder for the anti-subohmers).

The unit was from Dashvapes.com in Toronto - they have excellent customer service and given its engraved with their company logo and under 30 days old, I am sure they will take care of me. No worries there, they are a first class operation.

I went back to my trusty ZNA-30 and the popping continued, even more violently (more power obviously, as the unit can top out higher at a 30 watt limit). Having the 7-22 die on me motivated me to rebuild the Russian.

This time I used more cotton and ensured it was a tight fit and I gave it a little more cotton above the stack and positioned the tails properly - same coil by the way, just a new wick. Thats important to note because it isolates the coil from being part of the equasion. If it can vape without popping and just a rewicking, its the wick characteristics, not the coil.

Voila, no popping, no superhot vape (yes, I found the vape with the old build to be very hot) draw and the taste is smooth.

My conclusion is, since I am using the exact same coil, that this is a wicking issue. The lower you go on ohms, the more heat you get, the more wicking you need to feed that heat heavy juice hungry coil. Additionally the chamber has more cotton in it, so there is more of a sound and vibration buffer. The cotton is compressed tighter up against the inside of the coil, ensuring the coil has full coverage on the inside at all times. With more wick to draw juice as well, the coil is more efficient in supplying juice to the coil.

So, aside from the 7-22 going bye-bye, the ZNA-30 is rocking this rewick job very nicely. I hope this helps those struggling with popping, or at least gives you an approach to solving the problem in your own builds. I found the experience very educational.

 

[Firecrow]

It hasn't affected the quality of the vape, so again, I am reluctant to go digging into the new build...

Just to clarify, I did find after I had posted and vaped some more, the flavor went down, the heat went up. If you've dripped, you'd probably recognize this as having used up the juice and need to add more. So that adds to the evidence of poor wicking.

sounds like the battery vented. what kind of batt?

MNKE IMR-26650

Its got no signs of damage and is in the charger (Intellicharger i4) and there are no chemistry warnings as its charging just fine. Definitely the 7-22 electronics failing. I suspect its just coincidence and was a bad SX220 chip.