These are advanced coils for the HVT Sai Atomizer and due to their set up requirements are not generally recommended for people who are new to vaping unless they have a good level of understanding around the subject. They consist of a stainless steel crushed clapton coil sitting inside a bottom airflow ceramic cup. This style of coil can be setup to have accurate temperature control and fast heat up times (within 2 seconds), they also cool quickly so preserve flavour when loaded more heavily. The general method is to allow material to gently melt into the coil when loading, this improves vapour production and reduces waste.
Crushed clapton coils (also known as molecule coils) have hot spot which are found by putting the mod on wattage mode at around 10 Watts and heating the coil for a few seconds. Bright hot spots will appear. If you have ceramic tipped tweezers continue to pulse the coil allowing you to see the hot spots and gently squash the coil together to create better electrical contact. "Strumming" can also be useful if one area has been squashed too much and needs to be spread out, strumming is where you gently drag the tweezer tips over the wire as you would your thumb over guitar strings, to gently spread the wire apart. If you don't have ceramic tweezers the coil should be heated, then squashed, never applying power while the tweezers are in contact with the coil. It's possible to repeat this process until no hot spots are visible. At this point you take the coil out and let it cool, when you place it back into the atomizer the resistance reading will have changed and you will have a new baseline.
Now you can start calibrating to find the TCR Value if you're not satisfied with SS-Tc. We do this at 10 Watts to avoid overheating the coil. The most accurate way to find the correct tcr value is to heat it and measure different areas of the coil with a thermocouple to ensure it is heating relatively evenly, then measure the temperature at the centre of the coil as this is the hottest part. This is the area you want to calibrate your TCR to. The process can be done with an IR temperature gun as the wires aren't highly reflective but the results will be less precise. It is best to do this whole process in a darkened room so you can see the dull red glow as soon as it appears and adjust the coil accordingly. A very dull red glow is around 530C - this is a useful guide to avoid overheating your metals as this colour and light intensity is always irradiated at this heat. This is called "black body radiation".
SS316L should not be heated above 870 Celsius as it will loose its oxidation resistance (stops being stainless steel) and produces fumes. We've included a visual guide in the images so you can avoid overheating your coil if you don't have a multi-meter and thermocouple, though we'd advise investing in one as they're around £15 and you will be able to calibrate your coils with complete accuracy.
Our Clapton Coil Setup
To give a general idea - our current clapton coil has settled at 0.38 ohms, we run it at 22W with a tcr value of 66 (0.00066) and use fully open BAF and fully restricted TAF (still lets some through) to get the best results. If you have a mod that power the coil on SS-Tc you might want to just change the temperature instead for convenience.
If you buy any spare coil or bucket with a Sai Atomizer you can get 10% off the price of the coil/bucket, just enter the discount code "cheaperplz" at checkout!
Like all coils these need cleaning and eventually replacing. These coils are extremely difficult to clean if you are not using high quality material with very low levels of plant fats due to the plant fats polymerizing on the surface of the coil (form a hard non absorbent surface). We suggest regularly heating them to around 200C and turning them upside down to allow excess oils to flow out onto tissue, then heating around 20C above vaping temp and blowing gently until the vapour has largely stopped. For general cleaning we perform a gentle burn on wattage mode (10-13 Watts) ensuring the coil doesn't go past a dull red colour. That way when new material is added and vapourised at lower temperatures on TC mode no contamination from prior use comes off with the vapour due to already being vapourized. When the coils no longer take on concentrate when warm then need replacing.
It is advisable to become familiar with ohms law when using any advanced coil for your own safety. We recommend only using these on regulated mods.
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HVT Sai - Stainless Steel Crushed Clapton Coil