Speaking of dry burns: a few days ago I finally went back to Stainless Steel, for the first time since I started this thread.
I've only made one coil, but it's working really well. 8 wraps of 25G SS317L, coming out to about 0.48Ω. I'm running it at 215°C on the Dicodes, with TCR set to 0.001. I used to use 0.00105, but based on
@vapealone 's research into the TCRs of different alloys, it seems 317 has a lower (worse) TCR than other alloys. Which incidentally makes me want to try some SS304 as I think that might match the 0.00105 that Dicodes quoted for SS. I see that wireandstuff.co.uk are selling 304 so I might get some at some point.
215°C is a fair bit lower than I run most Titanium/Resistherm builds. I think this reflects the inherent low accuracy of SS. My guess is I am in fact achieving around the 230°C that I normally target, it's just that with SS you're only getting accuracy to the nearest 30°C.
But, as Dicodes said in their Applicataion Note For Temp Controlled Vaping, it's not the accuracy that is of prime importance. It's the
repeatability. It doesn't matter so much if the number on the screen is the actual real temperature. What matters most is that we can achieve a TC vape that tastes good, doesn't burn when juice runs out, and can be readily repeated.
So far I'm very pleased with the SS coil. It does taste good, it doesn't burn, and I've been vaping on the coil for several days and it's holding up perfectly.
And the best part is that it's proved to be dry burnable. I changed juice on that coil last night, and was able to remove the wick and then pulse the coil at 20W VW until it glowed red, to completely clean it out and remove all traces of previous flavour. The SS coils glow perfectly, just like Kanthal, remaining strong.
The other big advantage of dry burnable is that contact or part-contact coils are much more reliable - you can test fire the coil, dry burning it to check it has that nice inside-out glow, and that therefore there are no hot spots. I've found that's useful even on non-contact coils, just to be sure the coil is firing right.
Stainless Steel is very cheap - much cheaper than Resistherm - and therefore I think it's definitely a worthwhile TC wire.
But the big downside is that, currently at least, its use is limited to a small range of mods. Unlike Titanium and Resistherm, you can't adjust temperature on an Ni200 mod. You need a TCR adjusting mod. Right now that means Dicodes, DNA 200, or the SXK mods - though the latter are not going to be as good a vape as the former two. There's also the new Smok XCube 2 which is a TCR adjusting mod, but annoyingly won't go lower than 0.00150; 50% too high. That likely will work to some extent for SS with a temp adjustment, which I haven't tested yet. I do plan to contact Smok to ask them to lower the TCR to 0.00100 in a future update, enabling full Stainless Steel usage.
TLDR: If you have a TCR adjusting mod, give Stainless Steel a try! It's cheap, strong, dry-burnable, and gives a good repeatable TC vape. Just be aware you might need to play around with the target temp to find the right spot, and that might be 20-30°C (40-60°F) different to your 'normal' temp.
