Last Updated on December 5, 2023 by Team Spinfuel
The World of the [RDA] Coil
by Joseph C. Martin, III
Anyone new to vaping goes about their endeavors in various ways. I got into vaping to help others and myself refrain from smoking and purchased a small personal vaporizer. It worked nicely, however it did not produce the huge, powerful clouds that I saw others easily breathing out and smiling about afterwards. “How can I do that?” I wondered, and what started off as a simple form of curiosity became a sincerely gratifying obsession –building coils.
Spinfuel is a great place to go to read reviews and watch videos on variable wattage devices and subtanks. Here are three websites that offer vaping kits and variable wattage devices:
I found Spinfuel as I was researching vaping and trying to understand what others were speaking of in regards to their devices and practices. I was only going to be able to obtain one good device, so I wanted to research the markets in order to find a great one. I chose the IPV 4s from pioneer4you.com, and it is amazing. The IPV4s is available here:
The IPV4s has yet to be reviewed on Spinfuel, but it is a wonderful device; if you are having trouble making a decision, this is great variable wattage mod. Mine does not have a re-chargeable port, many people think the provided usb cable is for recharging –it is not. The cable I received was for the software upgrade, only. A good re-charger is the Nitecore D4, because it re-charges batteries independently.
As Spinfuel is a great place to read and watch reviews on mods, subtanks, e-juice, and e-cig pens, and even a great place to learn some vaping jargon, you may enjoy what I have to offer in regards to building coils for RDAs. Go ahead and read Spinfuel’s vaping glossary to learn what you want to know in regards to the very basics of vaping nomenclature, and supplement this knowledge with what I have to present in this article on coils and RDAs.
Some people get into vaping by acquiring a variable voltage mod with a clearomizer or comparable device. They work fine; yet we all wonder, “Can there be another way?” The answer to this question is yes. We can build our own coils for RDAs and fine-tune our vaping experiences. I personally enjoy making coils with my EnvyDealz Coil-Jig, 24-32 gauge Kanthal wire available from many vendors, and authentic 22mm RDAs. I also always check the ohms resistance of my coils with an ohms reader or a variable wattage device that reads what resistance the coil has. Any coil you build with the above mentioned Kanthal wire will show a resistance of 0.4 to 2.8 ohms and will be safe for vaping. I usually pass my wires over the top of a burning torch and dip them in freshly-stirred baking soda water. Doing so straightens the Kanthal, partially, and allows for lower resistance. There is no need to torch and dip the wire, however I have found that it works fine to do so.
For great initial videos on building various coils and vaping, check out:
Check out all the many others you will find in the side-links, too. To find new videos, remember to do a search on “coil building,” and consider what many experienced coil builders have to say. Many vaping pros have videos on YouTube.com that show how to wrap the wire and install it inside of an RDA in various ways and styles. It is a fun way to vape and also a fun hobby. When your subtank coils burn out, you can use an RDA. RDAs have this advantage- you can always rebuild and replace their coils every two weeks or so.
Many readers may ask, “Is there anything to be afraid of, in regards to building my own coils?” Or they may ask, “Why would I assemble an atomizer with my own coils, when I can always go out and get a subtank device?” Well, to be honest, you can. There are always dangers in using powerful lithium ion batteries. To make it short, if you short circuit a battery, it can burst. Do not let this notion scare you, though; as long as you use Kanthal wire and IMR lithium ion batteries, your risks can be minimized (even if you are not an electrician). Never line up multiple batteries in a series circuit (which is ‘stacking’ them on top of each other), and never use flashlight lithium batteries for vaping. An example is Nitecore. They carry a line of 18650 lithium batteries that look like they would be great for vaping due to their slightly higher wattage output, however they are not IMR batteries and should not be used for vaping. Their line of IMR batteries are dependable and safe, however.
The whole idea behind building your own coils for an RDA is to better specify your own prefered cloud production or vaping experience. It is fun and rewarding. While you can easily get a subtank or clearomizer with a 510 connection (the small threaded part on the bottom) which will vape fine, here is how to build a coil…
First, chose your RDA. There are hundreds of them. Try the five links above, and check out the companies reviewed right here in Spinfuel.
While most of those vendors carry mods, many of them also list authentic 22mm RDAs on their websites. Pick one out you think looks interesting or stylish, most of them are both. Be sure, too, to inspect the RDA for its air holes for your desired airflow preferences. You can also obtain an RDA from a vaping store. The “Tug Boat” RDA is a popular choice and comes in many colors. Stick with the 22mm RDAs for your first few builds, the larger 29mm RDAs will be highly similar and easier to do if you chose to, later. Most 29mm RDAs work with the larger 26650 batteries and mods and are harder to find or cost more. I prefer the 22mm RDAs, because one can still produce a large cloud without too much heat from the coils. These work with 18650 sized IMR lithium ion batteries –be them one or two, depending on your modular device.
Often, when you order an RDA, it will come with some extra screws, a small screw driver, and possibly some smaller-gauge wire and even organic cotton or the more elegant silica wick. These things are fine and are a good idea to keep around. Also, for instance on Amazon.com, when you add an RDA to your cart, you will see a wide selection of products below your order others also viewed. You will need to get Kanthal wire, some wire cutters, and some organic cotton. Check out this Spinfuel link on coil building:
Remember, use the silver-colored Kanthal. Never use copper wire for vaping, especially with a mechanical mod. The resistance of copper wire is low and may be dangerous. It is best to choose a variable wattage mod, as seen in the reviews on Spinfuel.com. You only need about 30 watts of output for great vaping. If you come across an RDA or even a mod with copper connections or posts, do not worry. They are made that way and are perfectly safe; just do not install copper wire for your coils.
Two other things you will want to add to obtain are an ohms reader (I have a small Drok model) and a coil jig. A coil jig is preferable though one is not necessary, you can always wrap Kanthal around a nail, ice pick, drill bit, or a selected screwdriver. The ohms reader is contingent on the device that houses your IMR battery or batteries –your mod. Your mod will have a 510 connection on top of it, which your RDA will screw onto with ease, just as a subtank or clearomizer will. RDAs may or may not be less expensive than high-end subtanks, however you can better control your vaping experience with a rebuildable atomizer, or RDA. Another reason to use an RDA is that you can change the coils out of it without having to re-order costly sub-ohm atomizers or replacement atomizer cylinders for your subtank or clearomizer, as previously mentioned. All coils ‘burn out’ with continued use or when using them with over 30 watts or both, and no one likes waiting for days on end for replacement atomizers.
Now, you may ask, “How do I do it?” Once you have obtained the items you need, you will have a mod, ohms tester, an RDA, Kanthal wire, wire cutters, organic cotton or silica wick, and some vegetable glycerine or e-juice. For a way to find an e-juice to meet your preferences, as far as flavor and nicotine content are concerned, check out one of the many review links here in Spinfuel. If you need a good variable wattage mod, check out the devices and reviews here in Spinfuel to find one you prefer. You will not need over 60 watts for a 22mm RDA. I usually vape with my IPV 4s at 29.5 watts when vaping with 29mm RDAs.
When wrapping wire, remember to wear safety glasses or shades for eye protection. Cut off about 10 inches of wire, twice. Most 22mm RDAs have three posts. The central post is the positive node, with one or two wire holes topped with tightening screws, and outer posts are to connect your coil to the negative node, in order to complete the circuit of a miniature heating element. The idea is the exact same notion of what works inside of an electronic cigarette, just not as tiny and easier to see and understand.
If you want to pass your two pieces of wire, one by one, above a torch and then dip them in water with baking soda in it, go ahead. The process slightly reduces resistance, yet is not necessary. If you have a coil jig, assemble it with the rod you want for the size of the coil you are after. If you cannot decide, go with an average size, about 3-4 mm, or a common-sized nail. Take one of your pieces of wire, and wrap it around the rod 5-10 times. Pull the wire snug and bend the final wrap to cause both sides of the wire to run parallel. Adjust the wire to the looks of the posts in the RDA, if needed. A common practice is to use only one coil, leaving one of the negative posts ‘free.’ There is no problem with doing so and can provide for more airflow – remember to tighten the unused negative post’s screw so that it does not loosen and fall off or become lost or lodged while vaping.
Once you have wrapped your first coil, clip off the wire so that you see the coil and about 1″ of wire on each side. Do this again, and you will have two small works of art to behold. The shiny little things are great for a photo album, as will be your RDA, soon. When you have two coils, loosen the screws in your RDA. RDAs come with removable parts. You can take the top off to see the posts –go ahead and check to make sure you remove the mid-section, if the RDA has one (the above mentioned Brass Monkey Style RDA does), so that you can better access the posts. I usually loosen the screws just enough to see a perfect ‘circle hole’ beneath them in the posts.
Insert your first coil into an outer post and the central post. Tighten the outer post and clip off the excess wire. If the central post only has one hole, as many do, leave the inner post open for the next coil. Insert the next coil on the other side of the RDA into the other outer post as well as the inner post. Tighten its outer post and clip off the excess wire. Now you will have two loose wires running through the central post. Adjust them so that the coils will not touch the outside of the RDA and tighten the central screw or screws. Clip off the two pieces of excess wire, and use a small rod or miniature screwdriver to adjust the coils, usually by bending them up just enough to be above the tightening screws. Always check the size and distance of the coils in the RDA to make sure they do not scrape the inside of the top of your RDA for proper airflow.
Now that you have installed your coils, you can straighten out some organic cotton and twist it into two inch long strands, just slightly wider than the size of the coils. Pull the cotton through the coils and wrap it around the top and bottom, or simply cut off part of the excess organic cotton and gently tuck it beneath the coils on both sides. Silica wick can be utilized in the same manner; remember that it tears easily. If you are trying to get two strands through your coil, bend a four inch piece of wire in half and thread the wick as you would when using a sewing needle. It is not too hard to do – if it does not work your first time, take a deep breath, exhale, and simply try again. With the organic cotton or silica wick installed the way you want it, you can add a few drops of e-juice to the cotton, both before and or after you test the new coils’ resistances.
As mentioned, be sure to test the RDA for its ohms. It should read from .3 to 3 ohms. As long as you are using Kanthal, your resistance will be safe for vaping. Install the RDA to the 510 connection on your mod. Now you can drop a few drops of your favorite e-juice or vegetable glycerine onto the coils. You can also add extra organic cotton, if you prefer, which can allow for a cooler cloud.
Too much organic cotton or e-juice or both will cause a condensed cloud and unwanted gurgling, so use discretion when adding extra organic cotton or e-juice. Replace the mid-section (if the RDA has one) and the top, as will as the mouthpiece/drip tip if you removed it. Press and release the button on the mod to see its reading, if it shows one, to hear the e-juice crackle, slightly. This way you know the device is working fine, and you may see small vapors come out of the air holes or the drip tip. That is a good thing. Now you can vape. I suggest holding the button down for about two seconds, while inhaling slowly, about three times. This way you can breathe in one large, relaxing cloud, and can exhale slowly to enjoy the flavor of your e-juice to watch the cloud blow away. The cotton in the coils will hold the e-juice for 5-10 serious vapes. Remember to add more e-juice before continuing to use the coils, especially if they taste dry. Change your coils out after using them over forty times, or every two weeks or so, especially if they become burned out or nasty-tasting. Sometimes, I rebuild my coils for different sizes and airflow or to change the thickness of the wire.
In conclusion, my two favorite 22mm RDAs are the Turbo RDA from Tobecco and the Brass Monkey Style RDA. You can find the Turbo RDA (it has a small, quiet cooling fan in it) from Vape Naked and the Brass Monkey Style RDA from the link above. As there are many 22mm RDAs out there, here is one with a review here in Spinfuel, as well as a link for more advanced coil building with titanium wire:
Building coils for RDAs is a fun and rewarding hobby. It gets easier to do and more fun with some practice, and it is gratifying to assemble a device that works nicely. Compare RDA vaping to vaping with subtanks, personal vaporizers, or clearomizers, and you will find that they both have their preferable attributes. Remember to only use IMR batteries and to always be safe. Thank you for reading and happy vaping.
J.C. Martin is a new writer for Spinfuel eMagazine. Although only recently a vaper JC has studied and practiced nearly non-stop and has become quite the expert at many vape related techniques. JC will be brining new columns and product reviews to our readers on an ongoing basis.