Post by Balders on Mar 4, 2017 16:19:37 GMT
I found this post on another forum, and it contained so much good information I thought I'd share it here.
There is more to coil building than gauge and wraps. You can build a .2 ohm coil with 28 awg if you make it small enough - but it's going to fry your wick and itself REAL fast. The fancy coils - twisted wire, Claptons, etc, and thicker gauges aren't just to look cool (okay, Some are just to look cool, lol), they also have different thermal capacities and juice wicking traits. So here's your primer.
Thinner wire has higher resistance, and lower thermal capacity. It heats up faster. Thicker wire has lower resistance, and higher thermal capacity - it handles more power, but it TAKES more power to heat. With any gauge, it's the actual length of the wire that determines the resistance - more wraps is just making a longer strand. Pretty simple.
BUT - the coil isn't the only thing you're dealing with. You also have a wick, and juice. If you get the coil too hot, it will overcook the juice and gunk up the coil. It will also fry the crap out of your wicking material.This is where coil DIAMETER comes into play, besides gauge and number of wraps.
When you run more heat (power), you need a to dissipate it over a wider area to avoid burning things. 20W on a huge coil will make a little vapour. 20W over a properly sized coil will make a quite a bit of vapour, 20W on a really small area will light something on fire. When you start approaching 100 watts - or more - this is obviously even more important.
Because that's not complicated enough yet, you also have to keep juice coming into said wick and coil. Thus, there is a practical limit to the length of the coil (lots of wraps) because the heat from the centre out - if it's a really long coil, the centre will heat up, and if you take a long puff, the centre will be dry by the time the outer parts get warm. Boom - nasty dry hit of death.
So the more wraps you use, the more diameter to need to keep enough juice in the middle to keep absorbing the heat - but now you're adding wraps AND diameter, so your resistance is going up, which is antithetical to getting more power - you've reached the "limit" of what's reasonable with that gauge wire and you need to move up to something bigger.
Ignoring the really tight stuff (30 awg and smaller) here are some rules of thumb for kanthal coils:
28 awg is good for coils up to maybe 2mm in diameter and up to about 9 wraps. 28 is great for vaping in the low 1 ohm range, and around 10-15 watts. You can also make a pretty small coil without much worry.
26 awg is good for moderate sub ohming, or for multi coil builds that don't go too low. Good up to 2.5 mm diameter and maybe 7 wraps, vaping around 20-25 watts on a single coil or a moderately powered dual coil setup. Inside diameter should be at least 2mm.
24 awg is good for making a fairly low resistance single coil in the .4-.5 range, or a good dual coil setup without going absurdly low resistance and blowing up batteries. Good up to 3mm diameter and vaping up to the 40 or MAYBE 50 watt range on a single coil, you want to be careful getting toward 7 wraps because it's thicker and you're making a pretty wide coil at that point. 2mm is a BARE minimum, risking dry hits.
22 awg makes very low resistance single coils. You can easily build something around .25 with a single coil with 22 awg kanthal. You want a pretty big diameter to keep it fed, and more than 5-6 wraps isn't a good idea. Multi coil builds with 22 awg will result in irresponsible ohm loads. Under 2.5 mm inside diameter is a guaranteed bad hit unless you take a really short puff.
Hope that helps.
There is more to coil building than gauge and wraps. You can build a .2 ohm coil with 28 awg if you make it small enough - but it's going to fry your wick and itself REAL fast. The fancy coils - twisted wire, Claptons, etc, and thicker gauges aren't just to look cool (okay, Some are just to look cool, lol), they also have different thermal capacities and juice wicking traits. So here's your primer.
Thinner wire has higher resistance, and lower thermal capacity. It heats up faster. Thicker wire has lower resistance, and higher thermal capacity - it handles more power, but it TAKES more power to heat. With any gauge, it's the actual length of the wire that determines the resistance - more wraps is just making a longer strand. Pretty simple.
BUT - the coil isn't the only thing you're dealing with. You also have a wick, and juice. If you get the coil too hot, it will overcook the juice and gunk up the coil. It will also fry the crap out of your wicking material.This is where coil DIAMETER comes into play, besides gauge and number of wraps.
When you run more heat (power), you need a to dissipate it over a wider area to avoid burning things. 20W on a huge coil will make a little vapour. 20W over a properly sized coil will make a quite a bit of vapour, 20W on a really small area will light something on fire. When you start approaching 100 watts - or more - this is obviously even more important.
Because that's not complicated enough yet, you also have to keep juice coming into said wick and coil. Thus, there is a practical limit to the length of the coil (lots of wraps) because the heat from the centre out - if it's a really long coil, the centre will heat up, and if you take a long puff, the centre will be dry by the time the outer parts get warm. Boom - nasty dry hit of death.
So the more wraps you use, the more diameter to need to keep enough juice in the middle to keep absorbing the heat - but now you're adding wraps AND diameter, so your resistance is going up, which is antithetical to getting more power - you've reached the "limit" of what's reasonable with that gauge wire and you need to move up to something bigger.
Ignoring the really tight stuff (30 awg and smaller) here are some rules of thumb for kanthal coils:
28 awg is good for coils up to maybe 2mm in diameter and up to about 9 wraps. 28 is great for vaping in the low 1 ohm range, and around 10-15 watts. You can also make a pretty small coil without much worry.
26 awg is good for moderate sub ohming, or for multi coil builds that don't go too low. Good up to 2.5 mm diameter and maybe 7 wraps, vaping around 20-25 watts on a single coil or a moderately powered dual coil setup. Inside diameter should be at least 2mm.
24 awg is good for making a fairly low resistance single coil in the .4-.5 range, or a good dual coil setup without going absurdly low resistance and blowing up batteries. Good up to 3mm diameter and vaping up to the 40 or MAYBE 50 watt range on a single coil, you want to be careful getting toward 7 wraps because it's thicker and you're making a pretty wide coil at that point. 2mm is a BARE minimum, risking dry hits.
22 awg makes very low resistance single coils. You can easily build something around .25 with a single coil with 22 awg kanthal. You want a pretty big diameter to keep it fed, and more than 5-6 wraps isn't a good idea. Multi coil builds with 22 awg will result in irresponsible ohm loads. Under 2.5 mm inside diameter is a guaranteed bad hit unless you take a really short puff.
Hope that helps.