Chapter 8: Custom Built Devices

Chapter 8: Custom Built Devices

Alison Brown

<<<Chapter 7: Mixing e-liquids

Glossary of Vaping Terminology >>>

Quick Links to sections in this Chapter:

There are several reasons why a dripper is brilliant, and they are useful for any vaper to have, especially if you’re mixing your own e-liquids.

  1. Change flavours quickly

    The main benefit of a dripper is the ability to change flavours quickly and often.

    If you love the range of flavours you can create with your e-liquid, drippers could be for you.

    Flavour-chasers find drippers really useful for trying out new flavours.

    As you only add a few drops of e-liquid at a time, it doesn’t take long to vape and then you can decide whether to have the same flavour or a try out a new one.

  2. Test out new e-liquids

    DIY e-liquid mixers also use drippers to test out their recipes.

    Whether that’s testing out a range of e-liquids with different flavours or testing the same recipe mixed at different percentages (go to ‘How to mix flavours’ for a step-by-step guide to mixing or check out ‘Top 5 tips for making the best vape juice’), drippers mean you can try them all out quickly.

    It’s also ideal for checking whether your e-liquids are steeped enough as you can add just a few drops to test them before deciding whether you want to vape the whole lot immediately or leave it for a few more days.

  3. Great flavour

    A dripper means your vaping device consistently functions well and produces a high-quality vapour.

    You can choose one which enhances the flavour and adjust the settings of your device so that you get maximum taste from your vape juice.

    If you prefer high vapour production to flavour, you can still customise your vaping device with a dripper to get a lot of cloud.

  4. No spitback

    Because there is no tank, there are no problems with ‘spitting’ and popping as this comes from e-liquid pooling around the coil.

  5. High performance

    The fact that the coil is not constantly exposed to e-liquid means that it doesn’t get gunked up by thick VG or sweet flavour e-juice (go to ‘Effects of different e-liquids on your device’ to find out why this happens and what you can do about it).

  6. They’re cheap

    They’re not very expensive and so you can try them out.

Maintaining your dripper

With a dripper, you obviously don’t need to clean your tank and you won’t need to clean your coil as much, either.

However, you do need to ensure it’s kept clean. Residue from saliva or e-liquid can build up on the interior of the drip tip and affect performance.

To clean it, simply detach it from your e-cigarette and rinse it under warm water, dry it thoroughly and re-attach it.

If you want, you can wash it more thoroughly with washing-up liquid and rinse it with warm water.

If you’re the sort of vaper who is happy to share your vaping device, you should clean the drip tip (or mouthpiece) regularly.

Next steps If you want to customise your vaping experience further, go to Building your own coils for a step-by-step guide or check out ‘Using sub-ohm coils safely’ to make sure you stay safe while you vape.


Using sub-ohm devices safely


These days, you can buy sub-ohm vaporisers off-the-shelf and get everything you need ready-made. 

That gives some assurance (if you buy from a reputable retailer) that your vaping device and accessories will adhere to safety standards.

If, though, you choose to custom build your own device (the mod and the coil) then you must take responsibility for ensuring you are safe.


Using the coil safely

You should use the right coil for your device, which means following the manufacturer's guidelines. 

Using the right coil means that your battery and mod are working at an ideal level and there is no unnecessary strain on either of them which will cause them to overheat or short circuit.

When making your own coils, you should research the types of coil and the material which are appropriate for your device and style of vaping.

Test the coil using an ohm-reader. 

It will ensure you know the exact ohm-rating of your coil and will make your calculations accurate. 

When adjusting the settings on your vaping device, you need to know the exact ohm-rating on your coil so that you can calculate the safe wattage and temperature range.

If you're making your own coils, you need to test them more than once. 

Not only do you need to test it using an ohm-reader when you first make it, you need to test it regularly as you use it to ensure it is not damaged.


Using the mod safely

The mod is the battery and electronic part of your vaping device. 

Because it is an electronic device (and one you pair with liquid, at that), it needs to be kept clean.

Regularly clean your mod by wiping it with a cloth to stop any build-up of dirt, dust and e-liquid. 

Ensure that the ventilation holes, USB port (if there is one), buttons and tank connection are clean and clear. 

Do not use water to clean it as it could splash or leak and come into contact with any of the electrical pieces of the mod.

The ventilation holes should always be clear, whether that's free from gunk and grime or not covered by material or your hand (if you accidentally hold your e-cigarette incorrectly). 

This is to stop your battery over-heating.

It keeps your device functioning properly and, more importantly, it keeps you safe.

If you're new to sub-ohm vaping, you might want to use a regulated box mod. 

They allow you to adjust the wattage but they have safety features built in, such as preventing electrical shorts which could damage the battery.

A mechanical mod is one which is unregulated and therefore can't detect battery or circuit problems like overheating, short circuit, high current, low voltage or high voltage.

That means you have to be the one detecting any of these problems if they arise.

Maintaining your mod and checking it regularly are important to keep it functioning properly and making sure nothing goes wrong.

The greatest danger that a damaged mod poses is the sensationalist-headline 'exploding' batteries. 

Lithium batteries don't explode but - if they are damaged - they release hot gas.

That's why it's so important to keep the vents clear, so that 1) they don't overheat and 2) in the rare case that the batteries do leak gas, it can escape. 

Otherwise, the gas will build up and the pressure will cause the device to break at its weakest point, usually with some force.

You definitely don't want that to happen while your e-cig is in your pocket or near your face.

That's why battery maintenance is so important, particularly for mechanical mods.

Using the batteries safely

Arguably, the batteries are the most important part of your sub-ohm vaping device. 

If used correctly, they are quite safe but, if mis-used, they can become dangerous.

Basic battery safety is common sense. 

Don't expose batteries to water and avoid keeping them in extreme temperatures (like a hot car, for instance). 

If your battery wrapper becomes damaged, don't continue to use it; either see if it can be re-wrapped or replace it.

Only use the type of battery recommended for the device. 

Using the wrong size or power battery can cause your device to malfunction and damage it.

The most common type of battery for sub-ohm vaping is lithium. 

This is because, if they fail, they vent gasses more slowly, which makes it much less likely that they'll catch fire or 'explode'. 

You should never exceed your batteries' amp limit. 

Always follow the manufacturer's guidelines.

Finally, never carry loose batteries in your pocket. 

If they come into contact with metal objects (like keys or coins, for instance), they will create a circuit and you will have a live, unprotected electrical current in your pocket.

Top tips for battery safety:

  1. Always carry batteries in a battery case
  2. Keep them dry
  3. Don't keep them in extreme temperatures
  4. Never use a damaged battery (or one with a damaged wrapper)
  5. Don't over-charge your batteries
  6. Check on charging batteries regularly

For more battery safety tips, go to 'How to use your device safely'.


Next steps

If you're starting to use sub-ohm devices and want to find out how to enhance the experience, you can try Temperature control vaping which uses a regulated mod.

To find out how to custom-build your device and coils, read on to 'Building your own coils' for a clear guide.


Building your own coils


Experienced vapers often build their own coils.  It's important to be extremely careful when doing this as it will affect the way your vaping device functions and needs to be compatible to be safe.  For more information about safety, go to Using sub-ohm devices safely.


Why build your own coil

Although coils aren't that expensive, they can add up, particularly if you vape a lot.

If you're fed up with having to change your coil, you can build your own - it's cheaper to buy the materials than a pre-made one.

You can also re-wick them instead of replacing the whole thing, which makes it even cheaper still.


What you need to build your own coil

As with taking up vaping in the first place, there is a start-up cost. 

However, the ongoing cost of making your own coils is much lower than buying pre-packaged ones.

To make your own, these are the things you will need which you can use time and time again to make as many coils as you like:

  • An ohm-reader
  • An RDA which suits your vaping style
  • A 2mm screwdriver or a 2mm drill bit
  • An additional small screwdriver or Allen key that fits your RDA's screws
  • A small butane or propane torch
  • Ceramic-tipped tweezers or needle-nose pliers
  • Small wire-cutters or nail-clippers
  • Scissors


These are the materials you will need to construct the coil you're going to use:

  • Resistance wire (of whatever appropriate material you choose - go back to Best wires to make your own coil for some guidance)
  • Wicking material (usually cotton)

Step-by-step guide to building your own coil


  • Calculate the number of wraps
  • Before you start wrapping your coil, you need to calculate the number of wraps it needs to reach the desired resistance. 

    There are numerous tools for this online but you need to ensure you use a reliable coil-wrapping calculator.

    It uses the wire size, coil type, inner diameter and length to calculate how many wraps you need to achieve your target resistance.

  • Oxidise the wire
  • Oxidising the wire makes it less springy and easier to work with.

    Firstly, cut the length of wire you need. 

    Particularly if you are starting out, you might want to cut an extra couple of inches so that you have something to hold.

    To oxidise the wire, you need to use the tweezers to hold the wire and then use the torch to heat the other end of the wire. 

    Light the torch carefully and hold it at one end of the wire until the wire glows orange and then slowly move the torch along the wire to about half way.

    Let the wire cool and then repeat the process at the other end of the wire until the whole thing has been oxidised.

  • Wrap your coil
  • You'll need to use the screwdriver and the tweezers to do this. 

    Take the screwdriver and place the wire over it, close to the handle.

    Use a finger or thumb to hold the wire firmly in place so it doesn't start to twist or move.

    Wrap the wire around the screwdriver as many times as you need. 

    Keep the wire as tight to the screwdriver as you can to eliminate any slack. 

    Try to keep the coils as close to each other as possible without overlapping them.

    Both leads (the ends of your wire) should be facing the same direction. 

    This means the wraps are complete.

    Don't remove the coil from the screwdriver yet.

    At this point, your coil is made and all you have to do is install it and test it.

      Installing your custom-built coil

    1. Loosen the screws in the post hole
    2. To put your new coil into your RDA you'll need to loosen the screws. 

      We don't advise removing them completely as it's harder to get them back in, especially if you're trying to hold more than one thing in place. 

      It's also really easy to lose them if you take them out.

    3. Position the coil
    4. Hopefully you have kept it on the screwdriver as this makes it easier to position without risking bending or distorting it.

      Move the coil (on the screwdriver) into position and place one lead in the positive post hole and the other in the negative post hole. 

      Position it in the centre of your RDA - it's easy to do this if the coil is on the screwdriver as it will maintain its shape while you adjust the leads.

    5. Secure it in place
    6. Once it is in place, you can tighten both the post screws. 

      Be careful not to tighten them too much as that might sever the wire and you'll have to start again. 

      They should be secure but don't have to be tight, just enough to hold the wire in place.

      Carefully remove the screwdriver from the middle of the coil, keeping the coil in shape.

    7. Trim the leads
    8. Finally, all you need to do to finish installing your new coil is to trim the leads as close to the post as possible so you don't have extra wire getting in the way and heating up.


        Testing your coil

        This is an important step when making your own coil. 

        Testing it to make sure it works efficiently will help to keep you safe. 

        It will also allow you to calculate your wattage accurately to keep your mod and batteries working.

      1. Put the RDA on the ohm-reader
      2. To test your coil, which is securely fitted to your RDA, you need to screw the RDA onto your ohm-reader.

      3. Check it doesn't have a short
      4. Your ohm-reader will let you know instantly if your coil has a short circuit.

      5. Measure your coil's ohm-rating
      6. The ohm-reader will display the ohm-rating of the coil.

        It's common for coils to vary in range to within 0.2 ohms. 

        If it displays the target resistance to within 0.2 ohms, you've successfully made the coil you wanted.

      7. Adjust it
      8. If your ohm-reader shows that your coil does not have the target resistance, you'll need to adjust it.

        Turn the ohm-reader off while you adjust it, or detach the RDA.

        Try these simple checks:

          • The first thing to check is that the screws are tight enough that they fit snugly against the leads
          • Check the position of your coil to make sure it isn't touching any of the posts or part of the deck it shouldn't be (you don't want the metal wire creating a circuit with anything else)
          • Make sure the RDA is screwed fully onto the ohm-reader

          If one of these techniques works, you can move on. 

          If not, you will need to make another coil.

          If you continue to have an issue with building a coil to your target resistance, double-check your calculations to make sure you're winding the wire the correct amount of times.  If you still have problems, it's likely to be an error in your ohm-reader or your RDA.


          Installing your RDA onto your mod

          Once you are sure your coil is safe to use and is functioning at the correct resistance, you can install your RDA onto your mod.

          Once you've attached your RDA to your mod, test it again by firing your mod until your coil begins to glow. 

          When it's glowing, stop firing your mod. Use the tweezers to gently squeeze your coil together.

          Wait for it to cool and then repeat this process until the coil glows evenly, starting from the centre and moving outwards.

          Wicking your coil

          You can use a variety of wicking material such as organic cotton, silica wick and eko-wool. 

          The most common type is cotton, though, as it's efficient at wicking and doesn't distort the flavour of your vape.

          To wick your coil, you need a piece of wicking material which is thick enough to fit snugly inside your coil and long enough to stick out by about half an inch either end.

          Push the wicking material through your coil. 

          You can use the tweezers to help draw it through the other end. 

          Another trick is to twist it, which makes it narrower and therefore easier to feed through.

          If the wicking material doesn't go through easily, it's likely that you're using too much. 

          If it's going through really easily, though, it probably means you're not using enough.

          It's a delicate balance and it takes practice to get it right. 

          Too much wicking material will mean it's less efficient at drawing e-liquid up to be vaporised, whereas too little will mean it won't evenly touch the coil and will be likely to burn and produce dry hits.

          Once your wick is threaded, trim the wicking material which is sticking out of the coil at either end so that it's just long enough to fold over so they sit on the deck of your RDA.

          To get the ends into place properly, put a few drops of e-liquid on them and fold them onto the RDA. 

          Make sure you don't push them underneath the coil as you want there to be airflow all around it.

          Finally, test it again. 

          This is to make sure that nothing has been knocked out of place while wicking it. 

          Also, it's advisable to check the resistance on the ohm-reader again as the resistance may have changed by up to 0.2ohms.


          Next steps

          If you want to know more about custom building your vaping device, whether that is the coil or the mod, we recommend you chat to other vapers who custom build their devices. 

          The vaping community is usually open and friendly, so if you have any questions or want some guidance, they're happy to help.

          Go to vaping forums and check out some of the best places to meet vapers online at 'Good resources for DIY e-liquid mixers.


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