Building Coils 101
If you’re interested in building your own coils then this beginners guide follows the steps in the accompanying video, teaching the basics on how to build your first 0.6 ohm coil.
There are risks associated with any electrical device, like an atomiser. Please follow these steps carefully and be sure that you’re building your coil safely.
Part 1: What you will need
An ohms reader
A rebuildable atomiser (RBA)
Resistance Wire (This guide uses 24ga Kanthal)
3mm screwdriver or coil jig
Butane or propane torch or lighter
Tweezers (preferably ceramic tipped)
Needle nose pliers or forceps
Small wire cutters or nail clippers
Wicking material (This guide uses organic cotton)
Part 2: Coil wrapping calculator
The number of times the resistance wire is wrapped changes the resistance of the finished coil. Before you begin you’ll need to work out how many wraps you’ll need to reach the desired resistance.
A quick and easy way to calculate the number of wraps needed is to use a coil wrapping calculator like the one at http://www.steam-engine.org/coil.html
Adjust the variables like the wire size, coil type, target resistance, inner coil diameter and leg length then the calculator will tell you the number of wraps needed.
The 0.6 ohm coil in this guide will need seven wraps.
Part 3: Oxidising the resistance wire
After the resistance wire has been cut to a workable size (around four or five inches is good) use the tweezers or pliers to hold the wire. Then use the torch or lighter to burn away any excess oil and oxidise your wire.
Be sure to let the wire cool before touching it again. Oxidising will reduce springiness and make the wrapping process easier.
Part 4: Wrapping the coil
There are two ways to wrap a coil, traditional or using a coil jig.
Before the coil jig was invented coils were wrapped by hand. For the example in this guide we’re using the shaft of a 3mm screwdriver to wrap our coil.
Take one end of the resistance wire and hold it firmly in place near the top of the screwdriver’s shaft then wrap the wire tightly around the screwdriver until you reach the target of seven wraps. Keep the coils as close together as possible without overlapping.
Once you’ve reached seven wraps both ends of the wire should be on the same side and you’ve completed the coil.
Using a coil jig makes it easier to build a coil without imperfections.
For the example in this guide use the 3mm bit in your coil jig to create a 0.6 ohm coil. Secure the bit into the coil jig’s post using the hex key that comes with the jig.
Feed the resistance wire into the wire hole of the post, leaving half an inch of wire sticking out the far side.
Next, insert the cap and turn it clockwise so it catches the resistance wire and twists it around the bit. Be careful as applying too much pressure will cause the wire to overlap and you’ll need to start again.
Once you’ve completed seven wraps and both ends of the wire are facing the same direction, remove the cap and then remove the bit from the post using the hex tool.
This should create a coil that’s more even and tightly wrapped than a coil created using the traditional method.
Installing And Testing
Part 5: installing the coil.
Take the build deck (where the coil and wick are found) of your RDA and loosen the post screws half way.
With the coil still on the bit or screwdriver, place one lead of coil in the positive post hole and the other in the negative. Then hold the coil in place with one hand while tightening the post screws. Be careful not to over-tighten or you could cut the resistance wire in two.
Trim the leads of your coil wire so they are as close to the ends of the posts as possible.
Next, remove the screwdriver or bit from the coil, screw your RDA into the ohms reader and measure the resistance. The completed coil should be close to the target resistance of 0.6 ohms but it’s normal for coils to vary by plus or minus 0.2 ohms.
Part 6: Pulse firing the build and eliminating any hotspots.
It’s strongly recommended that you use ceramic tweezers for this as you cannot fire your device and touch the coil to anything metal at the same time without potentially ruining the build.
Using around 25 watts, briefly fire the device until the coil starts to glow. The coil will probably not glow evenly to begin with.
When the coil glows orange apply pressure to the outside of the coil with the tweezers. Repeat this process of squeezing the coil until it glows evenly from the centre outwards.
Part 7: Adding the wick
Different materials can be used for the wick, like organic cotton, silica, ekowool, hemp and many more. For this example we’re using organic cotton.
Take a piece of cotton just big enough to snugly fit inside the coil. It can be helpful to wet one end of the cotton or twist it before feeding the wick through the coil.
After threading the wick through the coil, trim the wick so it’s just long enough to be folded over and sit on the side of the deck and down into the juice well. Be careful not to press any wick under the coil as its better for the entire coil to be exposed to the airflow.
Part 8: Testing the coil again
Double check the post screws and coil after adding the wick as the coil likely moved around when the wick was added.
Next re-check the resistance using the ohm meter. Its normal for the resistance to have changed by around 0.2 ohms after adding the wick. If the resistance isn’t roughly what you were aiming for then you’ll have to go back and recheck the process.
Part 9: Priming the wick
After finishing, saturate your wick with e-liquid. It’s recommended to pulse fire your RDA a few times after installing the coil and wick to get rid of the “new cotton” taste.
That’s it. The new coil is completed and you should be ready to vape and enjoy.