# Understanding heat



## Stranger (18/5/20)

I have a Recurve dual. First RDA that I bought with the thought of using it to try out DIY juice.

Everyone says that you get the best flavour out of a dripper, they are not wrong but I think the RDTA and some tanks are catching up quickly.

My issue was the heat. Wotofo kindly supplied 2 coils with the Recurve. Fused 4 core claptons. 28awg wrapped with 36. The packet said 0.26 Ohms. Really good looking coils, very well made. In the Recurve fitted as dual that means they are .26/2 = 0.13

For the purpose intended I have it on a Crea squonk which is a mech. No protection at all. I use my highest rated batteries, which are my Golisi 35 amp. This is only just acceptable with a 5% headroom. I need 28.46 amps. As a comparison , I can run my camping fridge for around 7 hours on those amount of amps at 12 V.

The heat generated by this setup is immense. I have no way to measure it ... but if you touch your lips on the metal part of the Recurve, it will burn you.

I decided too close for comfort for me and as I understand a little more thought I would build determined by the math.

0.25 or 0.5 per coil reduces the amp requirement to 14.8 amp. A 50 % headroom.

I used a single wire clapton Ni80 24/36. 6 wraps on a 3mm ID, 7mm leg length and it shows .5 per coil.

Coiled wicked and fitted. What difference does it make ?

Much cooler vape and the tank does not get so hot you can't touch it
Vapour production much the same
I can get a longer draw because I am not worried about burning my lips
It did change the flavour a bit. I get more fruit than custard out of the same Orange/custard mix
Much longer battery time, battery stays cool. I can use a 20 amp battery.
No difference in battery hit on the mech. As long as it has the amps to give it shouldn't.

What have I learned?

Batteries can be scary things. To hear the words from the vape sales guy " this one should be OK" will never again be taken seriously, or I could be a bugger and look him in the eye and say " explain to me why"

It is important to have a basic understanding of Ohms law, but even more important to understand the info given by the calculators. I tend to carry my stuff in top pockets, rather have a burned boobie than a right nut, or worse.

Just like building that dream kitchen for your wife, measure twice , build once and never rely on memory if you are over 50.

Simple coils work as well as fancy ones. Maybe, maybe not, depends on so may variables yet the results can be good with just plain wire. There is so much choice.

And lastly (never start a sentence with and ?) Don't be afraid to try and don't be afraid to ask questions. There is nothing wrong with being a noob. Everyone had to start somewhere and just as you get an answer to one question, more pops up. I think I will be a noob for a long time to come still.

A too hot tank for me was a problem that turned into an opportunity for more understanding. One that could possibly prevent that burnt right nut.

Reactions: Like 8 | Winner 1 | Informative 1


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## Resistance (18/5/20)

Nice write up. 
Well done on doing something different . I don't bother with calculators, I just take the wire wrap it around a screwdriver and when done then I check the resistance. 
I've also noticed that the thickness(bulkiness) of the coil plays a big role in heat build up and dissapation even if the resistance is high enough.
The coils also stays hotter for longer and the cotton seems to dry out for that period of heat in the coil that could lead to dry hits.
So coils are important plain or fancy.Wrong coil resistance bad vape. Bad vape, bad day.

Reactions: Like 2 | Agree 2 | Thanks 1


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## Silo (18/5/20)

Stranger said:


> I have a Recurve dual. First RDA that I bought with the thought of using it to try out DIY juice.
> 
> Everyone says that you get the best flavour out of a dripper, they are not wrong but I think the RDTA and some tanks are catching up quickly.
> 
> ...




The coils that came with my Recurve and Profile was some of the worst I ever experienced. Basically they burnt my lips and had no flavor, I quickly discarded them all. I now use 6 core wire or mirrored coils from Vaperite. I am happy, would say the coils are comparable but not preferred to mesh. Just thought I would check out this thermodynamics lesson, and saw could give my opinions.

Reactions: Like 1 | Thanks 1


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## Stranger (18/5/20)

Thanks for the reply the more the merrier. I like to hear others experiences.

Reactions: Like 4


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## Stranger (18/5/20)

Resistance said:


> Bad vape, bad day.



You ... good Sir ... have a way with words.

Happy vape day.

Reactions: Like 1 | Winner 1 | Funny 1


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## Silo (18/5/20)

I forgot to add that I also agree with your 0hmage not lower than .24 not higher than .32 0hms for most 18650's. It is near the limits and also a good spot if the wires diameter and materials are okay. But as preference I use only one coil at a time. I like centered coils. ni80 6 core 30g(or 4 core 28g) wrapped with 40g, 5 wraps @ 0.24 ohms is what I am running most of the time. I barely deviate.

That is why I think those Wotofo coils suck so bad, they seem to be super thin kanthal wrapped. My coil setup has only slightly improved since I first started vaping and quit smoking. I hate harsh popping spitback, so I have learned to avoid thick wrapped wire too! Thick wrapped wire can be hot like a stove too, I have had little success with wire that takes long to heat up and cool down.

Reactions: Like 2 | Thanks 1


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## Resistance (19/5/20)

Silo said:


> The coils that came with my Recurve and Profile was some of the worst I ever experienced. Basically they burnt my lips and had no flavor, I quickly discarded them all. I now use 6 core wire or mirrored coils from Vaperite. I am happy, would say the coils are comparable but not preferred to mesh. Just thought I would check out this thermodynamics lesson, and saw could give my opinions.


Picks or it didn't happen!


.

PIC of the coils please.

Reactions: Like 1


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## Silo (19/5/20)

Lekker early morning pics! So I just gooi, and hope it's all good. I am quite sure this fresh one, is one from wotofo. I definitely didn't wrap that.

I basically only use that 6 core roll to wrap coils. The sweeper coils were nice, but a little pricey. Most of this effort goes into trying to convert a smoker, or modify someones vape till they vape it happily.

Reactions: Like 1 | Winner 1


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## Chickenstrip (19/5/20)

I have two issues with your initial post. As far as I can remember, under the correct circumstances you can start a sentence with "And". And secondly, what on earth could you possibly consider worse than a burnt nut?

Reactions: Funny 5


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## Puff the Magic Dragon (20/5/20)

TWO BURNT NUTS !!!

Reactions: Winner 1 | Funny 3 | Can relate 1


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