What happened?! Staged heating nonsense.

[damndirtyvapes]

Well, sort of.

One of my favorite coils is a parallel 24/28g round kanthal with a 2.4 or 2.5mm ID, usually 8 or 9 wraps with the 24g and one less with the 28. Depending on the wraps I've done it as a single and a dual both.

Last night, I tried doing essentially the same thing with 22g and 28g. I fired at lower power than I'd use it just to get it glowing and worked out the kinks. As I started pushing the voltage, first it looked awesome and then it suddenly shorted.

I'm not an inexperienced builder or new vaper. I should have taken a picture but everything looked fine. It was actually glowing beautifully until the short happened. I really can't even imagine what occurred unless the resistances of those gauges of wire are simply too far apart, but I'm sure there are other possibilities. I did not think I was running it at a wattage that was unrealistic for the 28g. I use ceramic tweezers and don't manipulate while firing, anyway.

I realize without photos etc. it's only best guess, but maybe I'm just missing something.



couldn't resist. just watched that episode with my partner and he said "hey, that's kind of like you and a bad coil." I've taught him well.

 

[robot zombie]

Usually a connection problem ime. For instance, sometimes the screw doesn't make proper contact with the thinner wire and it arcs in there. And sometimes when that happens, it totally ruins the connection inside the offending post. Other times, the amount of torque needed to tamp down the thicker wire compromises the thinner wire and it gives out when you add heat to the pressure.

When you have leads tightened down and you apply heat, the wire gives to the pressure and gets squished down - all while the metal is actually expanding. Pulsing is sort of like a weak annealing of the metal. When you've got two different types of leads squished in there, shit can happen... ...and it all depends on how they're sitting in the posts. Next time, try not tightening them down as much before you pulse. Bring em to their final pressure gradually as you pulse.

And yeah, too much heat all at once can increase the likelihood of "perma-shorts" forming. If that's the case here, then you will absolutely have to reset the coil for it to be viable again.

First thing I'd try is removing the offending coil and positioning it so the screws come down on a different spot before re-torquing. Just make sure you choke up - never slide back, obviously.

Try grabbing the leads up past where they feed in and twisting up the sections that go into the posts. If you can manage it, get that bit in there to keep em from permanently offsetting.

It's probably a lot easier to do before you cut the leads because you can hold them in place up past the pliers while you bite down. I've never tried it with clipped coils.

Sometimes, I have this issue with claptons... ...just shorts that won't come out. Sometimes I swear little patches of metal actually fuse where they shouldn't... ...like they oxidize a little bridge to each other across this tiny point. Sometimes, I have to split each wrap on the offending coil apart, fire with em spaced a couple of times, squish em back, and tug em flush with the bit to work it out.

If the gauges are too far apart, sometimes the thinner wire will melt. It doesn't have to completely melt away to short, either. I've seen it happen. You'll know if this happened when you pull them out of the posts. Personally I get better results with close gauges, though I've definitely never had that problem with 28/24.

If that ain't it, I dunno what to tell you. I've never experimented with unequal wrap counts before. Could have something to do with that.

This is why I don't mess with staged coils unless there's a clapton in there lol. They can be such a pain in the ass sometimes.

Also, handy little tool for calculating parallel resistors of different resistances: http://www.1728.org/resistrs.htm Just pull the numbers for each coil from steam engine, plug them into the parallel calc, and generate the net resistance. Just make sure you go by the actual resistance given by steam engine (the one in parentheses) and it will be quite accurate... ...usually within .01. Might be helpful for identifying problems you maybe wouldn't see otherwise.

 

[damndirtyvapes]

That all makes sense, thanks a lot for such a thorough post.

It was probably a connection problem, though I rarely have that trouble with this particular RDA. I've never had that problem with the 24/28 mix but this one was 22/28g. I suspect it was either that the 28g wasn't connecting as the 22 is so thick or else maybe they were a tad too far apart. Based on some steam engine fiddling, the 28g coil was probably around 1 ohm and the 22g was around .36. I am using the numbers in parentheses but I'm not sure if they're dead on since the two coils in parallel are essentially spaced? If you're just looking at each gauge of wire. But the calculated resistance in the tool you linked to came out to right where the coil was before it shorted.

I'm not going to go through point by point just now anyway, but suffice to say that was super helpful. Maybe the numbers above will help someone tell me whether this was doomed to fail from the start, but I wouldn't think 60ish watts is so crazy for that 28g wire. Maybe I'm wrong; like I said I had not tried this exact configuration until the other night. The 24/28g coil is obviously made with gauges which are a bit closer together in resistance.

Unless there's no point I'll probably try at least once more to see if I can't figure it out. I honestly don't love 22g wire on its own for some reason so I'm trying to figure out some creative ways to use it.

 

[raymo2u]

That all makes sense, thanks a lot for such a thorough post.

It was probably a connection problem, though I rarely have that trouble with this particular RDA. I've never had that problem with the 24/28 mix but this one was 22/28g. I suspect it was either that the 28g wasn't connecting as the 22 is so thick or else maybe they were a tad too far apart. Based on some steam engine fiddling, the 28g coil was probably around 1 ohm and the 22g was around .36. I am using the numbers in parentheses but I'm not sure if they're dead on since the two coils in parallel are essentially spaced? If you're just looking at each gauge of wire. But the calculated resistance in the tool you linked to came out to right where the coil was before it shorted.

I'm not going to go through point by point just now anyway, but suffice to say that was super helpful. Maybe the numbers above will help someone tell me whether this was doomed to fail from the start, but I wouldn't think 60ish watts is so crazy for that 28g wire. Maybe I'm wrong; like I said I had not tried this exact configuration until the other night. The 24/28g coil is obviously made with gauges which are a bit closer together in resistance.

Unless there's no point I'll probably try at least once more to see if I can't figure it out. I honestly don't love 22g wire on its own for some reason so I'm trying to figure out some creative ways to use it.

Twists the leads before putting them into the posts, this way the leads no matter what are getting a great connection.

 

[robot zombie]

I am using the numbers in parentheses but I'm not sure if they're dead on since the two coils in parallel are essentially spaced?

You can use the advanced mode to input wrap spacing. If you want to assume a perfectly clean coil, 22g is .64mm across and 28g is .32mm across. You can thus use .32 for the spacing of the 22g and .64 for the 28 and get a reasonable approximation.

But yes, that's something I never considered. In my experience, it still comes out pretty damned close, though... ...close enough to test for bad connections and shorts, anyway. Seems the spacing doesn't matter much, since you had the same result.

Some shorts don't manifest until after you apply heat. I don't know why this is. After pulsing and before getting all of the shorts out, a coil will usually read low... ...sometimes lower than it did initially. So maybe you didn't have a short at first and then as the wire shifted it either shorted and popped or simply gave out somewhere without ever shorting at all.

That aside, if the coil itself doesn't show any signs of a terminating short, then there's only one other place it could've happened. I still think that the wire just happened to be seated inside the post in such a way that it eventually popped under the heat and pressure in there. It's the weakest point and usually the first to give under heat.

It sure doesn't sound like it was doomed from the start. It should work. 60w wouldn't have been anywhere near too much, either. There should be a way to make that work without too much trouble. This could've just been a case of bad luck.

Try again, but this time, twist the leads where they sit inside the posts before mounting. Ime, and assumingly raymo's, it really works.

It usually makes for a better connection with parallels of any kind and doesn't seem to affect performance otherwise. Just helps ensure that the post is evenly biting-down on both leads.

I've actually been doing this with my like-gauge parallels lately and for the first time, they've actually been reading on-point rather than a .01-.03 above calculations (I work in the .16-.2 range so that's significant.) I also used to have a problem where one lead in my triple-parallel 28's would break off at the post. I could see the offending lead crackling where it met the screw and the whole coil fired half as bright. The twisting seems to have done away with that.

With a little skill, it also makes mounting easier, as the wraps lock into place and don't shift nearly as much when you tighten-down. Worth a shot. If that doesn't work, then we can start looking at other possibilities.

But since you're looking at other uses, why not try twisting it with 28g for the hell of it? Or maybe do a twisted 22g helixed with 28g? You could maybe even go up to 32g . It's gonna read low and be bulky, but that might be okay, depending on how much power you're working with.

Do you clapton at all? I bet it would work really well claptoned with something fine like 38g or 40g.

Personally, I'm fine with 22g. It was my main wire when I was predominantly using tube mods and 30A batteries. I liked to do dual .16 macro coils in my big-airflow RDA's for clouds, heat, and flavor. You can send it my way, if you don't want it

 

[damndirtyvapes]

Thanks both, lots of good ideas. Let me hit the most pertinent points, @robot zombie :

1. I will definitely try twisting next time. I am actually-- it sounds like wrongly-- a little obsessive about making sure that parallel wire builds never, ever, cross... including the leads/at connection point, but it sounds like as long as they don't cross *outside* the post holes then it's fine? Or is there something else going on with twisting the leads?

2. I can definitely try doing some twisted builds with the 22. I just haven't gotten that far yet! I do like 24g twisted with 28, so I don't see why I wouldn't also like 22/28 twisted.

3. I could consider the helix build too but meh. Probably only if the above or below doesn't do it for me!

4. I do clapton, sometimes. I need to get some finer wire again. I really have little use for it at this point besides claptons and I don't make claptons enough to need to re-up on fine wire the second it runs out, but it's in my next order What gauge would you recommend to wrap around the 22g? I usually do 30g around 26 or 24g but I'm not married to it or anything.

I think that's it for now! Thanks again to both of you, this was very helpful. And I can't tell you how much I appreciate you actually reading through everything. So many times I've made *similar* posts to this elsewhere and the first response was something like "maybe try a simple single coil instead of xxxx if you're a new builder..." *eye roll*

 

[raymo2u]

Thanks both, lots of good ideas. Let me hit the most pertinent points, @robot zombie :

1. I will definitely try twisting next time. I am actually-- it sounds like wrongly-- a little obsessive about making sure that parallel wire builds never, ever, cross... including the leads/at connection point, but it sounds like as long as they don't cross *outside* the post holes then it's fine? Or is there something else going on with twisting the leads?

2. I can definitely try doing some twisted builds with the 22. I just haven't gotten that far yet! I do like 24g twisted with 28, so I don't see why I wouldn't also like 22/28 twisted.

3. I could consider the helix build too but meh. Probably only if the above or below doesn't do it for me!

4. I do clapton, sometimes. I need to get some finer wire again. I really have little use for it at this point besides claptons and I don't make claptons enough to need to re-up on fine wire the second it runs out, but it's in my next order What gauge would you recommend to wrap around the 22g? I usually do 30g around 26 or 24g but I'm not married to it or anything.

I think that's it for now! Thanks again to both of you, this was very helpful. And I can't tell you how much I appreciate you actually reading through everything. So many times I've made *similar* posts to this elsewhere and the first response was something like "maybe try a simple single coil instead of xxxx if you're a new builder..." *eye roll*

Twisting the Leads where it enters the post will only ensure that they get a great connection as long as either wire get contact, the current will still take the less restrictive route and the thicker gauge wire will get more current passing through it. It would be identical results if you didnt twisted the leads and had a great connection on both wires.
Twisting wire...Im not a fan of twisted wire as much as claptoned wire, some people love twisted builds...Ive done Twisted, Square Twisted, Twisted Claptons, Twisted as Staging wire, and more...they all have their own benefit but my issue is getting the twisting perfect or it just looks out of place...I know...OCD..

Hope these give you some ideas to work with....

 

[damndirtyvapes]

Thanks again! Just a small update:

I'm not giving up on this build but didn't feel much like replicating it right this second. I took out the simple, 22g single coil I had in my Twisted Messes (where I tried to install the build in the OP) and instead put in a lightly twisted 22/28g single clocking in at .26, about the same resistance as the non-twisted single. It looks somewhat like the second photo above but is twisted tighter than that.

It is INFINITELY better for my tastes; I feel like an idjut for not trying to twist up some 22g with a thinner wire sooner. I'm sure I'd enjoy some kind of 22g clapton, too, but again I just don't have the wire right now. In the meantime, this is so much improved. If the only way I could use up the rest of my 22g were like this, I'd be happy... but I'm sure I'll figure out something a little more creative eventually

Once this is no longer functioning I'm going to try the parallel again, twisting the leads for better connection.

 

[robot zombie]

Thanks again! Just a small update:

I'm not giving up on this build but didn't feel much like replicating it right this second. I took out the simple, 22g single coil I had in my Twisted Messes (where I tried to install the build in the OP) and instead put in a lightly twisted 22/28g single clocking in at .26, about the same resistance as the non-twisted single. It looks somewhat like the second photo above but is twisted tighter than that.

It is INFINITELY better for my tastes; I feel like an idjut for not trying to twist up some 22g with a thinner wire sooner. I'm sure I'd enjoy some kind of 22g clapton, too, but again I just don't have the wire right now. In the meantime, this is so much improved. If the only way I could use up the rest of my 22g were like this, I'd be happy... but I'm sure I'll figure out something a little more creative eventually

Once this is no longer functioning I'm going to try the parallel again, twisting the leads for better connection.

Haha, sometimes simple is best.

I occasionally do elaborate builds with more involved processes behind them, but all of my go-to builds are very simple. Claptons, fused claptons, dual 23's, triple-parallel 28's, twisted 26's. I think you're lucky if simple builds wind up suiting you. All that means is that you'll never be stressing if you just gotta do a build but you're having a bad build day. You can always have something you love up and running quick and easy. I dunno, I tend to rely on stuff that's simple and easy to master. Everything else is strictly for fun and showing off.

EDIT: Just realized I never answered your clapton wire question. Generally speaking, the thicker your core, the thinner your outer needs to be.

A thinner core heats up faster and doesn't hold onto too much heat, so with the right amount of power, using something as thick as 32g isn't an issue. It won't get too hot, but it'll have a ton of surface area and it's more manageable with high-power. You can just bring the wrap count down to counterbalance all of the bulk and give it the mass/power balance it needs. That being said, I still think it is not the best option.

The philosophy I've come to adopt is that one should increase the wrap count or core thickness rather than use thicker outer wire if further increasing surface-area is the goal. I only change the outer wire gauge in order to fine-tune ramp-up and heating properties. I'm more likely to change the core gauge to accommodate the device pairing and desired mass. I also find that thinner outer wire is better, flavor-wise. I think many others who like their claptons would tend to agree with that. That's part of the reason why I tend to balance my coil to my outer wire rather than the other way around.

Thicker wires claptoned with 34g or lower tend not to be too viable. Number one, there's too much mass for the already slow core to heat the similarly slow outer wire. Number two, pumping through enough power to circumvent that causes them to get too hot when vaped in succession, as they retain so much heat that they cool down much, much slower. No amount of airflow or wicking can get you around this. It will be a rather slow and scorching vape that continues to sizzle and deteriorate your wicks after you let off.

For those, you should be using 36g or higher, preferable 38g or 40g. This still facilitates the unique performance benefits that claptons provide without sacrificing too much ramp time or cooling efficiency. The core pretty much supplies all of the surface area you need. The outer wire is just there to tame the heat and give you the flavor/wicking boost. 24 claptoned with 38g will heat up at least 4 times faster than it would with 32g and tends to produce better flavor as well as more vapor. Even though it has less mass, it's more efficient and makes better use of what it has going on.

36g is a good middle ground outer wire that will work well with just about any core. It's a bit tougher to work with at first, but you learn to love it. You can do any sub-type with any core using 36g and it will generally perform well and is easily tamed. I personally prefer 38 and 40 myself, but those can be limiting at times, as they don't always add as much surface area as thinner cores can benefit from.

TL;DR: get 36g and/or 38g at a minimum. Though really, it's not a bad idea to pick up 500ft each of everything from 32-42. They have their uses.