Flat-pack coils

[Giraut]

Hello everybody,

About 2 years ago, I discovered the best coiling / wicking method ever for TC with Ni200. Seriously! Well, it works very well with other types of wire too, but it's harder to do. It works great with Ni200 because it's very soft. I call the coils "flat-pack coils" because the coils are flat, and the wicks need to be unusually well packed.

Having been away from the forum for a long time, I thought the method was common knowledge - since it's so simple. But my local vaping buddies keep telling me they never saw anything like it. So I checked around, and I can't seem to find anyone who does it too. So I figured I'd share. Here goes:

First of all, the "coils" aren't really coils. They start out as regular 2.5mm I.D., 28-gauge, 12-wrap Ni200 coils with a 1mm spacing between the wraps. Then I flatten the coils between my thumb and my index finger, with the legs pointing inward or outward depending on the distance between the atomizer posts, and flatten them further gently with a pair of pliers. They end up looking like this:

I mount them on the atomizer in such a way that I can pack the cotton tightly between the coils and something solid, like the bottom of the deck for atomizers with top airflow, or the post blocks on atomizers with bottom airflow.

Then I gently dry-burn them - gently because at first, only a few loops will fire, the others being shorted. I dry-burn them until all the loops light up properly.

For the wicking, it's rather counter-intuitive compared to round coils: I cut a length of cotton about the width of the coils, and fold it over 2 or 3 times into tight wads. Then I lift the coils gently, slide the wads underneath, then push the coils back onto them.

The coils should be pressed rather hard onto the wads to pack them even tighter: ideally, the cotton should be packed tight enough that the coils rest flat on the wads after pressing the coil firmly against them with a finger. The more cotton, the tighter packed the wads, the better.

Here's what my coils look like on various atomizers. Sorry, some of them are pretty dirty, but at least they show that I really do use them

Once they're in place, regardless of the type of atomizer I use, with these particular coils, single coils invariably end up between 0.17Ω and 0.20Ω, and dual-coils between 0.08Ω and 0.10Ω. As for the settings, 480F-500F work perfectly with all my mods, and 35-40W for single coils to 50-60W for dual-coils.

So, what's so great about flat-pack coils you ask?

1/ No dry-hit, ever. If you get a dry hit, you haven't packed the cotton tightly enough. In that case, open the bell, press the coils further into the cotton with your finger and it's gone.

2/ Very predictable TC.

3/ The wads of cotton last forever, and the coils need much less cleaning. I can go 15 days between cleanups. When it's time to dry-burn and re-wick, there's just a drop in vapor production: no funny taste, no dry-hit, nothing nasty.

4/ Re-wicking is very easy: simply lift the coils gently with a small screwdriver, remove the wads of cotton, dry-burn the coils in water until they're clean, insert fresh wads of cotton, fold the coils back and voila.

I urge you to try flat-pack coils: they're well worth it!

 

[Everpresentnewb]

seems like you would get hot spots where the coils cross each other. Im sure since your using them your not, but I would love to see some firing shots.

 

[Giraut]

You do get hot spots when a flat coil is brand-new and fired for the first time: only 2 or 3 wraps fire at first, so you pulse the coil quickly to avoid melting it. Then, after a few pulses, as the coil warms up and cools down, the surface of the wire oxidizes and the hot spots "resolve themselves". Eventually all the wraps heat up nice and even.

Exactly like with round coils with touching wraps really: you have to pulse them, and sometimes "comb" them, to get them glowing evenly too. The difference with a flat coil is, when it's finally primed, it glows evenly from one end to the other - unlike a regular coil which glows from the center toward the edges.

I'll try to shoot a video tomorrow.

 

[Twisted Vaping]

I do also believe that hot spots are no problem at all. If this was the case you wouldn't be able to use regular Micro coils too.

The only thing I am wondering about is the airflow. With my round coils the inside has to tranport the juice, the outside is touched by the air on it whole surface.

But interesting idea! May work with some fancy/exotic coils though.

 

[Giraut]

The only thing I am wondering about is the airflow. With my round coils the inside has to tranport the juice, the outside is touched by the air on it whole surface.

The coils don't necessarily have to hang in the breeze, like most people think. If they did, RDAs with pure top air intakes wouldn't work - yet evidently they do very well indeed.

The truth is, as long as there's negative pressure inside the atomizer and the coils aren't too far from the flow of air, the vapor they produce will be picked up and mixed into the airflow by virtue of Bernoulli's principle. It works exactly like a carburetor.

Don't focus on getting air flowing directly onto the coils. The atomizer will work just as well if they're just next to it.

But interesting idea! May work with some fancy/exotic coils though.

No need to wonder: just try it for yourself Seriously, all it takes is a few minutes to figure out how to best position the flat coils to maximize pressure on the cotton without blocking the airflow in your particular atomizer (and maximize the amount of cotton you can stuff behind the coils), and another few minutes to do the build. The worst that can happen is, it'll suck and you'll have wasted 20 minutes.

 

[Giraut]

Here's a build I did on a TFV8: dual 10-wrap kanthal flat coils with 2 flat Fiber Freaks wicks and 1 wad between the coils. It reads at 0.85Ω. This is a flavor-oriented build that still chucks decent-sized clouds at 35W. Best enjoyed with the airflow 2/3rd closed.

 

[Giraut]

seems like you would get hot spots where the coils cross each other. Im sure since your using them your not, but I would love to see some firing shots.

Okay, it's taken me a while - for lack of time - but today I really had to clean/rebuild a few atties. So I figured I'd crack out the video camera and shoot the videos I promised.

Sorry I ain't no professional Busardo: the videos are kind of cheesy, and things aren't always in focus. I shot them with a photo camera in video mode on a tripod, with the screen facing the other way - so I couldn't even see what I was doing. Also, they're unedited, so they're long-ish. But I thought at least they'd give a truthful account of how easy it is to work with them coils.

So, here's a video of me doing a TC build (dual Ni200 flat-pack coils) from the bare wire to the first toke:

And here's a video that shows how to clean a build:

Firing the coils start at 12:30 in the build video, and 2:40 in the cleaning video.

 

[Giraut]

New atty, same build Here shown in the Kylin RTA:

 

[Johnnytraveler]

Amazing. I'm gonna have to try this.

 

[Dutch0hms]

New atty, same build Here shown in the Kylin RTA:

Isn't that gonna leak from the bottom airflow ?

 

[Giraut]

Nope: If the wicking is done right, the cotton absorbs as much juice as it can hold by capillarity and no more. Leaks only occurs when other factors come into play - such as deliberate overfilling when using a RDA, or not enough cotton in an RTA's juice intakes to hold a vacuum in the tank when it's tilted sideways, to prevent flooding.

 

[Dutch0hms]

Nope: If the wicking is done right, the cotton absorbs as much juice as it can hold by capillarity and no more. Leaks only occurs when other factors come into play - such as deliberate overfilling when using a RDA, or not enough cotton in an RTA's juice intakes to hold a vacuum in the tank when it's tilted sideways, to prevent flooding.

Alright, i assumed it would condensate and leave some drips once in a while underneath the airflow. Whatever gets the job done right haha

 

[Giraut]

Exactly