Max Wattage for 28AWG Wire?

[zachn85]

Hey guys,

I want to build my own coil, I've built a few on 26AWG and had no issues going up to 30W with 0.7ohm. I want to build my next coil on 28AWG, just wondering, because it's slimmer, will it have a wattage limitation which may fry it?

Basically asking, how high can I go on 28AWG with a VW mod (subox Mini)

Thanks

 

[MMW]

When I go 28g-32g I end up doing a parallel coil.

 

[zachn85]

Thanks, but that doesn't answer the question Single thread coil, not parallel, how high can it go on 28AWG?

 

[coolerat]

28ga is tootle puffer wire for sure.

Very hard to work with as its so thing. Very hard to shape and dry burn as it will pop a leg like nothing.

It gets very hot. This is the number one reason I almost never use 28ga. I like a cool vape and 28ga get HOT!!!!!

Prolly the only thing I have 28ga on ATM is a Squape for a Provari. My Provari tops out at 15w and thats a VERY hot vape.

So guessing I'd say if you like a HOT vape maybe 12-15W and medium warm maybe 8-12 and for cool 6 or 7w.

 

[bussdriver]

That's a pretty loaded question. Several factors go in to determining the power needed in a coil. Wire gauge, diameter, # of turns, etc.

Go here and wind your coil. Play with the wattage and the various coil parameters and see how they affect the heat in the coil (heat flux).
Coil wrapping | Steam Engine | free vaping calculators
Then play around with various wire gauges, diameters and turns. Move the wattage figure up and down, watching the heat value.

This is a pretty good page to find out loads of data about coil winding.

 

[zachn85]

Sorry should have gave you guys more info.

My current 26AWG coil is reading 0.7ohm, it's a 2.5mm diameter over 6 wraps, and I'm using it with 27-30W with no dry hits or burned hits at all. Reason I want to go 28 is just so I can do 4 clean warps to get 0.8ohm and not 6 as I like making spaced coils and 6 spaced wraps can get a little messy on the Subox Mini RBA deck.

 

[ismokeinbinary]

I used 28awg at 50w for a while, usually in the 0.4-0.6 ohm range. I've been hooked on claptons lately though. Never got to go any higher, not sure I'd want to..

 

[zachn85]

Did your 28AWG coil have any trouble maintaining 50W? I'm aiming for 0.7-0.8 at lower W, of say 24W or so. I hardly think it will fry it but just want to make sure.

 

[ismokeinbinary]

Did your 28AWG coil have any trouble maintaining 50W? I'm aiming for 0.7-0.8 at lower W, of say 24W or so. I hardly think it will fry it but just want to make sure.

I use dual coils, but no, they never had problems.

 

[Rabbit Slayer]

Does it really matter if it is wicked and juiced, as long as the coil doesn't have hot spots?

 

[coolerat]

We all like different things and all but the heat flux on dual 28ga coils is gonna appeal to a very small number of people.

 

[herb]

Actually 28 gauge has been the most popular gauge over all others for years , these days i could see 26 gauge being the most popular but 28 has always been ideal for the overwhelming majority of vapors .

Not too thin and not too thick , quick enough heat up time and doesn't deform constantly like 30 and 32 . I believe many vape 28 at over 20 watts with zero issues and many used to go over 30 watts with no issues either.

 

[inspects]

28 ga wire is good when twisting two pieces together, you end up with more coil mass.

 

[zachn85]

Cool, I'll try my first 28AWG build soon and see how it goes.

 

[suprtrkr]

Aaahhh... the issue is not wattage but amperage if you're talking about burning a wire in two. I have run 28 ga as high as 70 watts. In general, you should set your wattage to the total resistance of your coil assembly, not the wire diameter. Ohm's law being what it is, lower resistance will tolerate higher watts. A three wrap 28 coil can be burned hotter than a 10 wrap 28 oil. Use Steam Engine, and pay particular attention to the radiated power from the coil surface block out to the right. I find I get a good, flavorful vape at between 100-200mW/mm^2 of coil surface. Less, it doesn't make a lot of vapor. More and it gets hot and then burnt. I adjust my wire gauge to keep my desired resistance in the coil surface power range that works well with the juice.

 

[inspects]

Google

 

[zachn85]

Aaahhh... the issue is not wattage but amperage if you're talking about burning a wire in two. I have run 28 ga as high as 70 watts. In general, you should set your wattage to the total resistance of your coil assembly, not the wire diameter. Ohm's law being what it is, lower resistance will tolerate higher watts. A three wrap 28 coil can be burned hotter than a 10 wrap 28 oil. Use Steam Engine, and pay particular attention to the radiated power from the coil surface block out to the right. I find I get a good, flavorful vape at between 100mW/mm^2 of coil surface. Less, it doesn't make a lot of vapor. More and it gets hot and then burnt. I adjust my wire gauge to keep my desired resistance in the coil surface power range that works well with the juice.

Good stuff, thanks, I've used Steam Engine but haven't paid attention to the mW/mm^2 ratio.

Looks like my current coil is pulling 110mW/mm^2 which is like you said, probably why I get a good flavour and a good amount of vapour. However, with 28AWG it says the flux will be 222 which is double so maybe using 28 is not the right thing after all.

 

[zachn85]

So I've checked again, it was giving me 110 for 10W, when I raise it to 27 it gives me 299... Does that make sense? It sounds like an awful lot. I'm getting loads of vapour and no burned hits at all. Not sure if it's calculated correctly?

Here's what I input:

When considering the heat flux before building, what value should I input in the W? The one I'll be using or the max W of the mod?

 

[bussdriver]

The coil wrapping calculator is good for finding the spot which you prefer, and making comparisons with other builds.

Let's throw a couple more variables into the picture. Whatever the heat flux shown in the calculator, the airflow across that coil and the wicking/juice cools it down. The better the airflow across that coil, the more heat that can be taken away. Kinda opens the window. But it is useful in comparing builds in the same atomizer.

Juice and wicking will also remove heat. Poor wicking allows more heat in the coil. Winding a genesis coil with that ss mesh or cable core will REALLY suck the heat away.

Lots of areas to play in. You kinda have to use trial & error to find what works best with each wire and each build.

You would plug in the value you are vaping at.

 

[zachn85]

Good points, I haven't realized that this number is for an exposed dry coil and haven't factored the airflow and the liquid cooling it down. I'm not sure how much it cools it in that case, but safe to say 40-50% less? If so, then I'm on the 150-170 mW/mm^2 range and that sounds about right because as I said so far I've had 0 dry/burned hits with this coil. Also plenty of airflow, my wicking is pretty good and it bubbles regularly.

The only question is when building do you aim for the heat flux to be in the green range before or after the cooling/airflow is factored in...