Not saying this is right, it’s just what I’ve observed since I started making coils 9 months ago for two different MTL tanks (Siren 22 and Ubertoot UTA2) and two different DL tanks… (UD Bellus and Serpent Mini)
Spaced coils just ‘make sense’ to me. I mean, there’s plenty of wick/liquid area available to supply each strand of the coil, and because of that, the element won’t ‘burn’ the juice quite as much as a bunch of coils touching each other. And ‘exposed’ wires have greater surface area to heat the juice, compared to wires ‘nestled’ against each other.
But I got the shits reading all these people getting at least a week, sometimes weeks, out of a coil, when I was getting four days max.
So I experimented with contact coils and immediately got a week out of a coil, with 9.9/10 flavour compared to 10/10 flavour. And I found I could run a couple of Watts lower than a spaced coil for the same flavour and cloudage. Maybe there’s heat ‘sharing’ with the wires touching each other so we don’t need so many Watts input for the same heat output? (is this heat-flux?)
Anyways - I’m sticking with contact coils for now (even though in some ways it doesn’t ‘make sense’…)
My biggest problem with contact coils is the hotspots, and those things burn your cotton. I mainly use TC and there’s nothing that TC can do to prevent hotspots burning your cotton. I started off using contact coils (easiest to wrap) but I got turned around quickly when I didn’t have to clear those damned buggers dry firing the coils with spaced coils.
Flavor and taste are subjective to the person and can differ from tank to tank / rda to rda. I’ve seen multiple people who like different builds on different attys. The ultimate goal IMO is that you have a satisfying vape (and that it’s safe of course), however you get to that goal, whatever your preference.
Whether contact coils last longer, I can’t say anymore because it’s been such a long time since I’ve used them. Personally, I use DIY SS spaced fused clapton coils and mostly Koh Gen Do for wick and if I don’t mix too many totally different flavors, I can get a week out of it. A lot depends on your juice, the amount of juice you vape, the power or temperature you vape at so again, it’s very subjective.
I’m not too sure about heat flux and heat capacity. I thought steam-engine’s explanation was a bit confusing. I just tried a lot of different coils and kind of stick to what I like now.
I started wrapping spaced coils-they were easier to make and no troublesome hot-spots to work out. I switched over to contact coils for a little while, but preferred the flavor of spaced coils. I’ve used simple wire, clapton, fused clapton, twisted, chain and staple coils, but bang for buck, I always go back to 26 gauge simple spaced coils. It just works for my vaping style.
Are you not cleaning your coils? I’d venture a guess that most everyone (like myself) getting weeks and, yes, months out of coils is dry-fire cleaning between re-wicks. Of course that works with kanthal and ss…not sure about nichrome, and definitely not advisable for titanium or nickel. But with kanthal and ss I know for sure. I take out my old cotton, give a rinse under the tap, then shake off the excess water and dry fire. Usually I’m around 50 watts on my dual coil builds. Get a good glow, rinse, repeat until clean. Then wick and vape till dirty again.
Then again I know there are those folks so anal retentive that they can’t imagine doing this for fear of microscopic particles of ash or whatever. Whatever floats your boat. Just I use this method and it works great for many, many rewicks.
in my mind, i think it’s “juice sharing” rather than heat sharing. seems to me with spaced, each wrap has limited amount of juice directly accessible to vaporize, and the wraps “compete” if that makes sense? - with contact, we have a single, larger heat surface (pipe in that case) against all the juice in the wick. no “focused” heat in small spot. i tried both, always get better vape “experience” with contact - then when flavor mutes or vape feels too “fumey”, it’s time to dry burn, clean and re-wick. it’s fun.
Yeah, I also got good flavour from simple spaced 26G Kanthal coils, but had to run 20W plus so my single 18650 wouldn’t last a work-day. With 30g I can run 8-15W, get the same flavour, and my battery lasts a whole work-day…
I’ve tried to clean my coils with every method I could find online (hot water, cold water, tap water, demineralised water, quench while glowing, quench after glowing, cold rinse, no rinse) but I get metal taste EVERY time. Which is weird coz I glow them new to make sure they glow from the inside out… But if I do it after a few tanks, metal tang…
Yes they are an issue, but it only takes about a minute or less to fix - I pulse half-second bursts until I can see the coils is hot (usually notice a hot-spot or 3), then compact the coil with ceramic tweezers. Repeat, maybe turning the build around and squeezing from the other side, until it glows from the inside out. I don’t stroke coils anymore, just squeeze.
However, contact coils are pretty much asking for trouble if you run TC - Ohms all over the place, which doesn’t seem to matter with VW, which was one of the reasons I quit using TC…
It’s not just you-I get the exact same taste if I clean kanthal coils after they’ve gotten good and gunky. I don’t get the same taste with stainless, but with both metals(Kanthal and 316L SS) I find the flavor of my juices taste muted. I’ve actually stopped trying to clean my coils. Once they’ve gotten crud-crusted, I simply tear down, rinse/wash the atty(RTA/RDTA/RDA) and rebuild with new coils and wick. I’ve even started wrapping coils and rolling wick, then setting them aside for the RTA’s I use most often so that it’s one less step that need to do when I rebuild.
I agree, and that even includes brushing them with a metal brush, putting them in USC but they never get clean enough for me to really enjoy them. On top of it, if it’s not super clean by dry-burning them and rinsing them off, it costs more time and effort to clean them than to install a new coil.
Not sure if this is all scientifically backed up, but I don’t believe that dry-burning coils to clean them is the smartest idea (i have no issue with short dry-burn for hotspot removal, no need for excessive heat here). Applying (a lot of) heat to metal can change the composition of the metal and I don’t know how this will affect my TCR. I just know I can tell the difference between a new and a cleaned coil.
And the other thing is I use “fancy” coils. Just try and get all the gunk out of multicore clapton. Heating up gunk (and I know this for a fact) affects not only the flavor but produces the highest amount of harmful stuff that we inhale.
While I don’t know the long-term effects of this, I still try to be on the safe side of it and just replace that damned coil.
Others are obviously happy cleaning coils and reusing them even for months, good for them. This is just how I think about it
I’ve tried this quite a few times and it’s pretty easy to get the outside clean. However, when I wick, I often noticed that there was still black gunk coming from the inside of the coil and that really put me off. If I have to stand and repeat this cycle 20 times or more, why not save myself the time and make a new coil from scratch and have all the advantages from having a new coil?
I just don’t see the advantage of cleaning them, except for maybe a few pence for the metal.
I read that article and later saw a video from him giving an update as well, saying that dry burning to check for hotspots isn’t as bad as people perceived it from that article. I’m not worried about it. If I find that video again, I’ll post it.
The thing about cleaning coils is a whole different matter, that’s literally trying to put as much heat in the coils to make ash from all the gunk to be able to rinse it off… that is something I’m a little less OK with.
But again, it’s a personal thing. There are a lot of people doing this and have been doing it for a long time. I have yet to see anyone with any physical complaints about it, it would surely be all over the media if it happened.
I recently won an iJoy RDTA 5S on ELR in one of the giveaways. It might be approaching 2 months and I am still using the spaced Clapton coils that came with. The coils when new had a shiny silver look to the wraps which I took for nichrome. There were no specs, but I didn’t look too hard. I’ve been focusing on sweet juices with no added sweeteners to get a longer llifecycle, but I think I have only changed the cotton like every two weeks. I’m using TC on my DNA 250. Not sure which combination is delivering such a long lifespan, so just reporting like the OP. I’m usually very picky because flavor is everything …maybe it’s my juice, maybe it’s mystery metal Claptons, but it has been dramtically different.
To clean your coils while the OLD wick is still in there …put a few drops of distilled water (or just water) on your grimy wick and fire several times and watch it sizzle off a bunch of carbon. Might reduce the amount/duration of dry firing required to clean.
“Wet Firing” reminds me of the time I lost my job at Sea World for spanking the dolphins …BTW don’t google “spanking the dolphin” …just sayin’
I still have quite a bit! Rememer my story was my order came with a note/apology from the company that they were out of usual bags …so they stuffed a sandwich bag full! …no complaints re: double portion!