@superdang9000,
@ray_b, good work with the alternate metal coils for the SP! One coil build at a time, posting and sharing results, we can crowd-source this and narrow it down to several types of wires and shapes of coils that work well with the SP.
And since we're posting up some alternate coils and heaters for the SP that do work, I might as well share my results to show what
DOES NOT WORK, so that no one else out there holding the same failed ideas in their head that I did, don't have to go bother repeating them...
As I had hinted at earlier...I wanted to give some of these alumina
ceramic heaters I have lying around a try in the SP.
So first I tried these ceramic rods, about 0.5Ω each, 0.26Ω for a pair on the deck. Their "OEM" purpose is to heat up a quartz crucible which you dab off of, like a mini quartz banger, so they don't directly touch the concentrates in their default application, but I've also build a few RBA for RTA with ceramic wick where these rods do touch oils directly to vape them, and they work quite well in that application too. But can they make convection vape?
Well, no.
I use a TCR of about 140 for direct conduction, 225 to heat the quartz cup, and the rods don't have to glow for this. I knew I had to go much higher for convection, but raising the TCR # in increments of 25, going all the way to TCR 700, 750+
the rods were
definitely glowing, taking a long time to warm up, making the mod, CPU, battery & everything get pretty hot...
but no vapor at all! Hardly a wisp, barely even any flavor.
What a waste of good voltage and airflow. I would think the placement of the rods right over the air tubes & their size (similar to the notch coils) would make something at least...but nothing!
moving on....
ceramic donuts! 
Donut so bright, white and reflective!
The air holes on the SP whoosh right through the donut hole, maybe this is good?
Can I make it brief? Well, it also didn't work! 
I had the TCR # up to 600-700 (much higher than the 400 or so used for direct dabbing) and although the donuts didn't glow like the rods, I was only able to get a mere trickle of vapor from the large dual 13mm donuts with TCRs higher than 700, 400F temp. Needing over 60w and 8-10 seconds to warm up (slow) and making plenty of radiant heat, this seemed like a very ineffective way to vape on the SP. Maybe it could be viable with a larger cell or 2-cell mod and more watts, but it would still get hot af and not offer much benefit over the notch coils except not glowing?
So basically, alumina ceramic heaters...pretty big fail on the SP.
Maybe some other people can make this work, maybe a monster "quad rod" build would work without glowing (and make alot of heat too) but it just seems these type of heaters won't be competitive with metal coil builds on the SP. Someone had to try it!
So I went back to my original, default pair o' notches that came on my SP. A little beat, they ohmed in at 0.98Ω (what happened? I think the notch-segments contacted and semi-shorted. As soon as I test fired, even glow, right back to 0.125
)
I tried very carefully to align the position of the dual notches to be as even & symmetrical as possible. I think when the notches sit at odd, asymmetrical positions, it chars your flower load un-evenly more easily. A little tweaking on those notches, and quick, easy, full clouds are restored!
If anything, a slight hot spot in the middle, easy to stir away....
but still...
This video clears up alot of the health concerns involved with SS coils.
If I interpret this correctly, this is just more reason
not to trust the brittle little flaky notch coils? I can't tell just by looking at them if they glow brightly or dull. It's not a bright white glow but it's pretty bright and red at least, not dull. It's easy to accidentally knick or contact the coils when removing the middle section of the SP also, so that does not inspire confidence about cracking open that oxide layer.
I'd like to see some of you guys test some more nice potent,
low-glow &
glow free coil builds to help narrow it down for me. I'll huff
just a little more hexavalent chromium in the meantime
@withoutbliss even if you and guys like @KeroZen don't actually have the SP to be able to test these different coils with us, any productive ideas & tips on building coils, theory, what you think may or may not work well, any info like this is much appreciated!
Maybe I can even summon some of our other coil-pros like
@Accept,
@Boden, and
@2clicker to chime in with any thoughts / ideas for us stempodders? Yes, they like to dab off their coils, but maybe their familiarity can help us
floral-convectioneers too?
I think you guys are missing a key element here: we're not trying to heat a cotton wick, we're trying to heat passing air. It's way more involved than you imagine! You can't just transpose e-cig coil designs to convection vaping and expect the best results.
Coil geometry does play a huge role. Surface area too. How the atty air inlets are and their location etc. I reiterate, please read the BULLI and Project threads if you don't want to reinvent the wheel (granted it's less fun without pictures since imgur is gone but still)
This concept is not lost on me. To be clear, I'm familiar with TC mods, ceramic atomizers and building coils, but I'm still a bit of a convection newb, and I've never gotten into wrapping coils myself since I don't like dabbing off them either. But I have learned a little from browsing the coil pr0n in some of the good ol' coil threads in the concentrates section...
So for the SP in particular, I think relatively compact sized wraps, perhaps non-contact (the loops between the coils not touching / shorting each other, with space in between each loop) so the air can pass through the coil and make more convection, like our stock notches?
And also, using
"complex shapes" like braids, ribbons, alien wire, inception coils, etc, that have higher mass but also are more "porous" to passing air might be more powerful & effective than simple wrapped, round wire?
But I'm the new here, on the particular field of wrapping wire...so I'm happy to soak it up.
Much of it seems to revolve around the other components in a DIY vaporizer from what I was able to glean by skimming. Any chance you could point me to which pages I should be looking at for coil discussion, or even just a general coil style or length that was found to be more successful than others?
