Help with burning cotton

So today, I wrapped my first coil, added cotton, but my cotton is burning. I'm not sure what to do about it. Here are the details, and I'll attach a few pics:

- it's a single micro coil
- 28 gauge kanthal wrapped 13 times around a 2mm screwdriver
- the coil seems to glow really well from the inside out. just like I see on youtube vids.
- it's on a trident v2 using a single large airhole next to the coil
- battery is a Spinner with various voltages set from 3.8v to 4.8v
- I don't know the ohms. I'm guessing because I don't have a meter yet. I built this based on a Rip Trippers video where he used the same gauge kanthal at the same 2mm diameter, with the same # of wraps. His came out at 1.8 ohms so I'm assuming mine is similar. I'm also assuming I should be fine in the 1.4 - 2.4 ohm range. Please let me know if I'm wrong about this.
- The coil's legs are short (as seen in the pic). Can this cause probs?
- I'm not using an abundance of cotton. I'm putting it thru the coil and leaving enough to hang down to the base on either side. First time I made the cotton really dense and after awhile it actually burned the cotton into two pieces. Then I tried it with loose cotton, but still the cotton inside the coil seems to get charred or at least darkened a lot.
- when the cotton is fresh and soaked with juice I'm getting tasty, decently cloudy hits. After about 5 hits, I start getting the burnt flavor, the cotton gets blackened, but some of the cotton is still damp.

Any advice appreciated. Thanks!

 

I'm only an armchair quarterback but maybe post some pics with your cotton installed. Someone might twig as to what's going wrong. Sounds like not wicking for some reason.

 

Alright, lets see if I can help. This isn't rocket science, what you're doing here is trying to vaporize a fluid. The vaporized fluid removes heat, just like sweat evaporating off your skin. If there isn't enough fluid to vaporize at the heat source, the wick will burn. If the temperature of the coil is too hot, the wick will burn or the fluid will burn. Wicking is dependent on the viscosity of the fluid. PG is less viscous than VG, so a higher PG fluid will wick easier and faster.

To me, your coil looks too long. It might be fine for a mostly PG based juice, but its difficult for the cotton to wick through a choke point. The coil heats from the center, so this would be why you are burning your cotton in half. You could try a couple things:

1. Remove some wraps from your coil. This would make it easier for the juice to wick to the center.
2. Use a thinner juice. A thinner juice will be able to saturate the wick faster.
3. Use less cotton. I've found there is a balance you need to find dependant on the wattage and liquid you are using. When I vape a Kayfun at 8 watts, I use a lot more cotton than a microcoil at 40 watts.
4. Lower your voltage. Less heat means less burning, but it'll take more time to produce vapor.
5. Increase your airflow. Whether you make a larger opening or take a harder, faster drag, it will help to cool down the coil.
6. Make sure your airflow is directed at the coil. Even a little bit off can cause your juice to burn.

I might have missed something, but these are the basic things to look at when you have a problem like this. It should give you a good idea of what direction you want to go in.

 

If you fire it without cotton, does your coil glow nice and evenly, from the center outwards? You might have hotspots.

If not then its probably cotton that is too tightly packed within the coil area.

 

Thanks for all the advice. Really.

I think my cotton was too tightly packed. Since then I've tried a dual coil with 8 wraps each, and now I'm back to a single coil with 12 wraps. Works ok, but still really wary of smoking cotton while I'm vaping juice. Right now, my cotton is maybe too thin and not touching the coil enough, and I think it's causing me to get less flavor. The cotton still gets darkened a lot inside the coil, but I figure some of this is normal, especially depending on the juice.

Anyway, so does this mean that I should never vape my wicks dry? Will it always burn the wick at this point? Is that normal? Gonna have to do a some more research...

 

Sounds like you're going backwards. Normally the dual coil one would have more wraps. Identical dual coils will have half the resistance of each coil separately. I'd try a single 8-wrap coil if I were you.

If its touching the coil in all areas but you aren't getting much flavor, bump up the voltage.

Yes, its normal, especially with the darker juices. By the time I'm done with a tank of Moo Juice on my Kayfun the wick is black, its just the parts of the flavoring that didn't vaporize concentrating on the wick.

Yes, you should never vape any wick try, cotton or otherwise. If it can't cool the coil, the juice will start to combust.

 

Nice, thanks for that. I'm going to try this today or tomorrow.

Right now I've pretty much got the problem sorted out. Initially, my cotton was too dense, and my volts were too high. Since then I've tried a bunch of new cotton wicks and finally got a few working really well. When it's not dense, but fills the coil almost completely I get great flavour. And when I combine this with less volts and always avoiding a dry wick it works like a charm - no burning. I've also been lowering the voltage a bit after each hit and that's been working out well. Still going to put an 8-wrap coil in there next time to see how it goes.

Because I'm being really careful about not letting the cotton be too dense, I find that my thin, lone wick doesn't hold much juice. I'm having to re-drip after every 4 or 5 hits. But I guess that's just the way it is. I think I'm going to play around with a cotton cloud under the coil also to see what that's like.

 

Reason is because I don't really know what I'm doing. This is my first foray into making coils, and I don't have an ohms meter, so I've been wrapping the micro-coils based off a RipTrippers video.

I'm really curious about your setup. What gauge kanthal? Is it a micro coil? What diameter is your coil? What voltage setting(s) do you use? Do you use cotton? Do you have a pic?

 

I dont know how good (accurate) this chart is but it might be helpful to get a quick idea where you should be 'aiming for' to begin with.

http://www.vaporrater.com/images/Ohmschart.jpg

 

That is helpful indeed. I also found this sweet webpage:
Steam Engine | free calculators for your vaping endeavors

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Thanks! This info is really helpful for me. About the voltage I was curious where you set it on your iTaste vv 3.0, but no worries, I'll play around with the settings and see what works. Of course, I always see stuff on line about sub-ohm coils being dangerous with certain batteries (like the ones used in mech mods), but how about with my Spinner or your iTaste vv 3.0? Is there anything to look out for when using a 0.9ohm coil on those?

 

I was going to try your 0.9 wrap suggestion yesterday, but ended up deciding to try 32 gauge kanthal for the first time. I wrapped two mirco-coils of about 8 wraps each. I think it supposed to come out at about 1.4 ohms according to the SteamEngine calculator. I did a far better job of wicking this time, and have been getting the absolute best vape so far. Really, really satisfied with that setup. Because I was worried about burning cotton, I had been using tiny wicks which lasted 3 or 4 hits. It was quite pathetic. That got me thinking about trying dual coils again as I wanted to spend less time taking the top off and dripping. Then I finally got the hang of putting in a good fluffy wick and now I'm getting 7 - 8 solid pulls each time I drip. Good flavor and the most vapor I've seen so far. I'm learning by trial and error, and becoming more and more obsessed with vaping. I'm glad a got a nice satisfactory setup now that I know I can quickly replicate when necessary - that means I can finally start getting some work done for a change. This past week (my first vaping week) has been a total lost cause for everything unrelated to vaping.