Coil Building Principles Tutorial and Demo
Coil building really doesn’t have to be rocket science but if you learn the basics well enough it can truly become an art form. Here we talk about the basics to help people get started but these principles are universal and can be scaled up to any kind of coil build.
Getting Started :
- Get to know your Atty. Whether its an RDA, RTA or tank with RBA section. Or even if you’re simply rebuilding stock factory coil shells. Know the components, particularly on an electrical level.
- Make sure you have good tools. You’ll need resistance wire suited to your device. Cutters that can operate in small spaces and a good set of tweezers. Ceramic tweezers are ideal as they are heat resistant and non-conducting . If you try to shape coils with metal tweezers while there is current passing through them they’ll short and burn out. That means starting over from scratch. Scissors for trimming your wicks. Coil jig or screwdriver with a diameter supported by your dripper or tank. You can buy these elements separately or in one bespoke kit like the Coil Master or 521 Tab.
- When selecting your resistance wire make sure you don’t spend on wire that is too thick for the holes in your posts.
- Invest in good quality organic cotton. Regular cotton can sometimes be treated with bleaches or other agents. You don’t want to inhale that sort of thing.
Picking the right wire for your device or Mod Capabilities :
The quality of flavour and amount of vapour you can achieve are determined by two main factors. Coil surface area and airflow. The more of each you can achieve, the more vapour you will get. Achieving more surface area can be done in two ways. Increasing the amount of coil wraps or using more advanced wire sets or multi core wire sets. Clapton wire is an example of a basic multi core wire set. Increasing the wraps or using advanced wire comes at a price. You need more power to drive the coil. Using 5 wraps as an example, here is a rough guide to how much power your device will need to be able to output to use certain wire types:
- Single strand single coil = up to 10 watts or 4 volts
- Single Strand Dual coil = 15 watts to 30 watts or 4.8 volts up to 6 volts
- Dual Parallel Single = 20- 35 watts. Dual Parallel dual coil = 30 to 50 watts
- Single Fused Clapton = 50 to 80 watts Dual Fused Clapton = 80 to 120 watts ( Requires device with 2 x 18650 batteries )
- Anything more advanced than a Clapton will require more than 100 watts to drive it properly but you will need to research it as there are ways to reduce the load depending on the makeup of the wire in question.
Building requires experimentation to get it just right for your atomizer. As a general starting point if your device has an internal airflow inlet of 2mm diameter then your coil or coils should be about the same diameter. On more modern atomizers where the juice flow inlets are so big they have no relation to the airflow inlets, then about 3.5 mm is the maximum you could feasibly use in most devices presuming you are seating them horizontally as in the above example. Now not all devices have enough space for that depending on the wire you are using. So you may have to compromise. I would personally sacrifice using Clapton wire for say, a dual parallel build in order to have a bigger internal coil diameter.But only if the juice flow inlets are capable of keeping up with juice flow supply. If your atty has airflow less than 2.5mm in diameter then you won’t need big coils so 2.5mm to 3mm is the maximum I would recommend. This will become apparent when the tank is juiced up and you chain vape on it. If its a dripper, then the only restriction is the available space inside the deck.
Rules for building for safety and just getting it right first time:
- Wrap your coils tightly and neatly on your coil jig. You can determine the spacing later on in the process.
- Clip one coil leg (Excess wire at the ends of the coil) shorter than the other. This makes them easier to seat in the posts.
- Seat your coils as close to the posts as possible without actually touching them or directly over the airflow inlets if it is a bottom blown device like a Kennedy.
- Make sure the coils do not touch the outer wall or chimney section of the atomizer or the deck (bottom of the atomizer) . This would cause a short which is a safety hazard on a mechanical mod and is just bad joojoo otherwise.
- Check your Resistance in ohms to make sure there are no shorts which show as 0.0 ohms or significantly lower than you were aiming for. You can do this buy testing firing on most devices with safety protection built in that have an LED screen. For Mechanical mods you will need an ohms reader. This comes in the tool kits I listed above.
- Re check and tighten the post screws as you go along. Tighten until they are snug but not so much that you are forcing them or you risk stripping the screw threads.
- Use short pulses when shaping your coils using ceramic tweezers to bring the wraps closer together or space them apart. Be gentle as the wire is twice a malleable when it’s hot.
- DO NOT TOUCH THE COILS while they are hot. You will get a second or third degree burn and it will blister. Do all shaping of the coil once it’s on the deck and attached to a mod with your tweezers.
- Make sure your coils glow orange red from the middle outwards. If you get hot spots that will result in spitting Juice like bullets in your mouth when you vape it. The key to avoiding hotspots is even coil spacing.
- When building dual coils make sure both coils are as close to identical in shape, size, amount of wraps and distance from posts as possible. Check that the height from the deck is the same as well.
Wick properly or go home:
You generally get two types of decks in tanks. Tanks with decks that have a juice inlet on either side that is a channel that sits up against the outer chimney. Or you get a gaping hole or holes in the base as an inlet / inlets. In the video below I demonstrate what is known as the pancake method of wicking. This will work for the former. Basically your wicks will be long enough to just touch the deck but you must not block the juice flow inlets. Tanks with cyclops inlets , or big gaping holes in the deck work a bit differently. They need the wicks to just about sit inside the holes and for the wick density to be adequate enough to fill the hole itself but not so much that it would be tightly sat inside. In other words there needs to be space for the juice to flow up the strands of cotton. Cotton expands when wet. So you really only want to fill 70 or 80% of the aperture with cotton. Then kind of flush the cotton up a bit so there are no gaps. Which will prevent leakage. The dual fused Clapton build above is one such deck. Don’t stuff the cotton all the way through the deck either. You’re really just plugging the hole itself to it sits about 1 or 2mm inside the hole in terms of depth .
Rules for wicking
- Roll you wicks if you wish. This is required if you are using balls of cotton but if your cotton is from a rectangular pad it is not needed. Do not twist the cotton. This will prevent the juice from wicking properly and may cause dry hits.
- Use only enough so that the wick goes in through the coil snuggly. If it feels so tight that it might move your coil, then you’ve cut it too thick. Use the external diameter of your coils as a guide as to how thick you should cut your wick. So if your outer diameter of your coil is 4mm (3mm internal diameter) then this should be a good starting width for cutting your cotton.
- Twizzle then end of the cotton to get it through the coil more easily but otherwise try no to interfere with the threads too much. Straight threads wick faster than mangled ones.
- Once the wick is through the coil , and you’ve trimmed it to suit your deck, fluff the ends up as your scissors will have compressed them. Again this helps wicking.
- If you’re using a dripper leave enough length to just touch the base with all the strands . Excess wick kills flavour and wastes juice.
- Never dry fire your wicks. They’ll burn and you’ll have to start from scratch. Juice them up a bit , until they look soaked. This takes time so be patient . This will help you to seat them properly on your deck in any case.
- Change your wicks and dry clean/ dry burn your coils (without wick in them) every 3- 4 days or more. Sweeter flavours caramelize more. So they may need to be changed daily in some instances.
In theory in any case.
This should be enough to get you to reassembly of your tank and or dripper and you should be able to fill up and start vaping. For unique quirks of each tank that may impact on dry hits or leakage, I suggest checking Youtube for your specific tank. The rules set out here should see you right with 90% of the tanks and drippers on the market though.
Here is a video of a build on the Uwell Crown Mini RBA as an active example from start to finish. Please understand it was hard to keep everything in frame the entire way through and in focus as it was shot on mobile. Everything I discussed here though is shown in the video in some way or another. So it should be enough with the advice above to get you started in the right way.
And Finally here are some examples of what you can do if you practice , research and be creative :
Credit to the builders out in internet land as it wasn’t me who built these or took the photos. I’m sure they won’t mind me sharing it for educational purposes though.
Best of Luck- Tristan @ Ziggicig