Titanium wire, vaping and safety

[HolmanGT]

Both the dna 40 and the SX M's were set to 20 ...thats Watts for the dna 40 and Joules for the SX M's.

I don't understand why water cooling Ti vs NI would be different. Is there any reason heat transfer coefficients would be different between the two materials? I would think that's a matter of power delivered and the thickness of the vapor boundary layer/air velocity over the coil.

I know Pbusardo did some numbers on DNA40 preheat so we should be able to see how much preheat power that has. Unfortunately if I remember right he did the powerful and powerful+ numbers on the SX M at high power where the voltage max kicked in and he couldn't see the effect at all. I would guess if he had done it at lower temps he would have seen the kind of numbers that yihi shows in it's graphs.

Duane

Duane,

On the heat transfer Ti vs Ni shouldn't make any difference as long as the coil is in contact with the water soaked wick.

The classic is the boiling water in a paper cub over an open flame the cup will absolutely not burn until there is no more water in the cup.

Example:

 

[druckle]

Duane,

PB did the YiHi boost but he was having trouble analyzing the PFM signal correctly. The DNA40 boost is 40 watts for one second or until the temperature is within 100 degrees of TP whichever comes first.

Gotcha

Duane

 

[jks89]

There IS something screwy about the dna 40....same test as above with the titanium coil and RO water and I get 195F
I don't want to participate in a dna vs yihi argument but them's the facts.

Haven't read the last couple pages, but doesn't salt decrease the boiling point of water?

 

[Quantum Mech]

Haven't read the last couple pages, but doesn't salt decrease the boiling point of water?

increases it

 

[jks89]

increases it

Just goes to show you - Momma's not always right.

 

[awsum140]

I'm still waiting for my Ti to arrive. This conversation keeps getting way above my pay grade, thermal boundaries and such, but it sure is interesting. I think once my coils get built and wicked I'll just start out at about 150 degrees lower than I'm vaping at with Ni200 and raise it until I like the results. A "conversion table" would be nice, but I'm getting the impression that the conversion factor may vary from chip to chip as well as device to device and be affected by the specific liquid in use as well as wicking in the builds. Maybe I'm wrong about that, but just the differences with boiling water seem to indicate something more complex is happening than just the difference in resistance coefficients.

I would also speculate that the water, for the reference tests, needs to be either RO filtered or, better still, distilled to insure no mineral content which can affect boiling temperature. Maybe not a lot, but enough to change things depending on the wire and any possible chemical reactions induced by the heat. Again, I could easily be wrong and will leave that to the experts out there.

 

[TheotherSteveS]

Haven't read the last couple pages, but doesn't salt decrease the boiling point of water?

decreases freezing point! These effects of solutes on solvents are known as colligative properties if you are interested (you may know already of course!!)

 

[Quantum Mech]

Cleaned some Ti & thought would try building without annealing

Was a pita anyway but got it in there then had to rip it out & start again

Made the mistake of pulsing it with TP set at 270f

Hot legs turned grey & trying to reposition the coil must have broken off the coating as can be seen in the pic

Glad I checked with macro as my eyes could not see it

Will stick to annealing with a torch & setting to 212f for a couple of pulses before wicking from now on

 

[druckle]

Cleaned some Ti & thought would try building without annealing

Was a pita anyway but got it in there then had to rip it out & start again

Made the mistake of pulsing it with TP set at 270f

Hot legs turned grey & trying to reposition the coil must have broken off the coating as can be seen in the pic

Glad I checked with macro as my eyes could not see it

Will stick to annealing with a torch & setting to 212f for a couple of pulses before wicking from now on

Ouch. you're convincing me to keep on spacing and run them shiny.

Duane

 

[Rossum]

Made the mistake of pulsing it with TP set at 270f
Hot legs turned grey & trying to reposition the coil must have broken off the coating as can be seen in the pic

What kind of mod? Ti's gotta get darn hot before you get oxide thick enough to flake off. Any idea why you had hot legs?

 

[Quantum Mech]

What kind of mod? Ti's gotta get darn hot before you get oxide thick enough to flake off. Any idea why you had hot legs?

it was on the M class at 17j

the way the legs & 1st wraps either end lit up was strange

will try again later today to see if pulsing at lower TP & wattage makes the coil warm up more evenly

 

[Quantum Mech]

Ouch. you're convincing me to keep on spacing and run them shiny.

Duane

Yeah me too mate

Am going to stick with 5x spaced wraps of 26awg

You know how it is though, things work fine but have to try something else

 

[Quantum Mech]

Ok, after the anomaly of my last post

Have since made a nearly identical coil, just an extra wrap to last time

Pulsed dry at 14j / 212f ... looked ok

Vaped a tank full through it then pulled to check the condition of the coil today

Here it is still in place

And another shot showing the other side once removed

As can be seen its looking good, legs are perfectly clean still

Cant account for what went wrong last time ... maybe a poor section of wire, I don't know

Back on 5x spaced wraps again now of 26awg at 3mm as that lasts & vapes so well

 

[TheBloke]

The key difference with contact coils, at least based on my experiments with the SXK, is that the TC will not work for the first pulses. This is not unique to Titanium, I find the same with Resistherm.

So when you set it 270°F and fire, it just kept heating up - it thought the coil hadn't heated at all, or hadn't heated much, so it did not moderate the watts at all.

Were you able to look at the screen during those pulses? If you had, I believe you would see the temperature staying at 100°F or something similarly low. On the SXK VF it usually starts at 77°F and stays there for that first one or two pulses.

The way I get Ti contact coils working is:

• Pre-pulse the wire: about 150mm of wire pulsed on a spare atty in power mode @ 30W, until it turns blue
  • This is purely to make it easier to coil; well, and for the pretty!
• Build the contact coil, fit it in the atty
• Do some gentle pulses, short, watching the screen - expecting to see no rise of temperature, so knowing these are, again, uncontrolled power pulses
  • Do that at least two or three times until I see the TC kick in - temperature/ohms rising normally (you will only be able to see rising ohms on an SXK)
• Then start vaping, or do another pulse if you want, knowing this is now a controlled TC vape.

My experience with all TC contact wire thus far is that the shorting of the contact coils breaks TC completely - usually at first the resistance just does not rise, so the mod continues firing full power at it. It's very easy to torch the Titanium when that happens (one reason I'm so far preferring Resistherm, where I can treat it just like Kanthal and keep torching until it glows cleanly inside-out. See my post here for my recent findings on Resistherm contact coils.) Sometimes the opposite happens - resistance shoots up immediately, so it kills all power.

But after a couple of such attempts, you will see resistance rising normally, and you now have a functioning TC contact coil.

That said, your 'spaced' coil up there is so close to being contact as to probably make little odds. But if you do want contact - and personally I believe there are several benefits - it's definitely possible. Just remember it's not functioning for TC for the first couple of fires. And watch the screen as much as possible to verify this (having a VF makes this so much easier!)

 

[Quantum Mech]

@TheBloke Yeah I watched the screen as I pulsed it whilst still keeping the coil in view

First couple of pulses fine & quickly got the dry coil message

Then third or fourth time unlucky, the legs just lit up

There was no tightly touching coils or shorts to base that I noticed but expect that the coils were shorting between one another

............

5x spaced wraps & a quick pulse in place is doing it for me ok again now

 

[druckle]

The key difference with contact coils, at least based on my experiments with the SXK, is that the TC will not work for the first pulses. This is not unique to Titanium, I find the same with Resistherm.

So when you set it 270°F and fire, it just kept heating up - it thought the coil hadn't heated at all, or hadn't heated much, so it did not moderate the watts at all.

Were you able to look at the screen during those pulses? If you had, I believe you would see the temperature staying at 100°F or something similarly low. On the SXK VF it usually starts at 77°F and stays there for that first one or two pulses.

The way I get Ti contact coils working is:

• Pre-pulse the wire: about 150mm of wire pulsed on a spare atty in power mode @ 30W, until it turns blue
  • This is purely to make it easier to coil; well, and for the pretty!
• Build the contact coil, fit it in the atty
• Do some gentle pulses, short, watching the screen - expecting to see no rise of temperature, so knowing these are, again, uncontrolled power pulses
  • Do that at least two or three times until I see the TC kick in - temperature/ohms rising normally (you will only be able to see rising ohms on an SXK)
• Then start vaping, or do another pulse if you want, knowing this is now a controlled TC vape.

My experience with all TC contact wire thus far is that the shorting of the contact coils breaks TC completely - usually at first the resistance just does not rise, so the mod continues firing full power at it. It's very easy to torch the Titanium when that happens (one reason I'm so far preferring Resistherm, where I can treat it just like Kanthal and keep torching until it glows cleanly inside-out. See my post here for my recent findings on Resistherm contact coils.) Sometimes the opposite happens - resistance shoots up immediately, so it kills all power.

But after a couple of such attempts, you will see resistance rising normally, and you now have a functioning TC contact coil.

That said, your 'spaced' coil up there is so close to being contact as to probably make little odds. But if you do want contact - and personally I believe there are several benefits - it's definitely possible. Just remember it's not functioning for TC for the first couple of fires. And watch the screen as much as possible to verify this (having a VF makes this so much easier!)

What do you feel are the benefits of contact coils? I used them for a long time and now use spaced coils with only about the thickness of a razor blade between the individual wraps so the coils are still pretty compact and seem to work well.

Duane

 

[Quantum Mech]

That said, your 'spaced' coil up there is so close to being contact as to probably make little odds. But if you do want contact - and personally I believe there are several benefits - it's definitely possible. Just remember it's not functioning for TC for the first couple of fires. And watch the screen as much as possible to verify this (having a VF makes this so much easier!)

Here's my spaced coils set up which work so well there is no need to change really

Just as you do .... gotta try other things

 

[TheBloke]

hmm so it actually worked better the first couple than the later ones? Interesting.

I'll do some more Ti testing later today, see if I can get some consistent results. I've been on Resistherm exclusively the last few days.

@tchavei has been using contact Ti coils for a while and didn't mention pulsing, I think? Tony does any of this match your experiences? I know you pre-torch, but only to blue and my pre-pulsing to blue didn't seem to prevent me also having to pulse as a contact coil.

 

[BNEAT]

Spaced coils gunk-up less than contact coils. Other than that, I've never noticed any difference.

 

[Quantum Mech]

hmm so it actually worked better the first couple than the later ones? Interesting.

I'll do some more Ti testing later today, see if I can get some consistent results. I've been on Resistherm exclusively the last few days.

@tchavei has been using contact Ti coils for a while and didn't mention pulsing, I think? Tony does any of this match your experiences? I know you pre-torch, but only to blue and my pre-pulsing to blue didn't seem to prevent me also having to pulse as a contact coil.

The pre-torching will add a non conductive coating or more resistance at minimum

With electric taking the easiest route , expect that's why Tony & I have had better results torching