Hot Spots with SS wire

[danielpm]

Hello Guys! After purchased a Evic VTC Mini, I was curious about TC. So, to try it I bought some Titanium and SS. After many attemps, I just cant build a SS coil without hot spots. I tried everything: Spaced without dry burn, contact without and with dry burn (this last one using the method that I used in the past years with kanthal). No matter I do, I always have hot spots, resulting in dry hits. Everyone have/had the same issue, that can give some advices?
Cheers and thanks!

 

[Froth]

The reason that Kanthal coils don't have as much of a tendency to arc between wraps or "hot spot" is because the first time Kanthal gets hot it forms an aluminum oxide layer on the surface which insulates the wraps from one another which helps with taming hot spots, when you start to taste a change in your Kanthal coils the reason you experience that is because the aluminum oxide layer becomes depleted and eventually through continued use is entirely degraded.

Stainless steel contains no aluminum so the oxide layer which would insulate the wraps from one another takes longer to form, the benefit is that the oxide layer once formed on Stainless Steel is incredibly hard, in my experiences SS coils can last months without degradation. One of the most handy tips I can offer for working with SS wire is to pre-torch it before you even make a coil, so take a 12" length or so of the wire you plan to use and torch it orange hot and after letting it cool then build your coil with it. Other than that the only thing I do differently is to initially fire the coils with a whole lot of very short pulses(1/2 second button pushes) what this does if you're careful is it will allow ALL of the coil to heat up even with some hot spots in the coils, once you get them glowing orange and let them cool off a few times the oxide layer should be sufficient to insulate the wraps from one another.

What alloy of Stainless Steel are you working with?

 

[danielpm]

@Froth

Thanks for the tips! Will try tomorrow.. I'm using the UD 316L SS, 28". Didn't now about that oxide layer. I never let them glow orange to much because I was afraid to do something wrong.. I only did the necessary to make the coil in a "pretty" contact.

 

[Froth]

316L should be fairly straight forward, what I think is happening is you're simply not getting the wire hot enough. Torching the wire before you build a coil may be all you need to do, however if there are still hot spots then slowly pulse the fire button until you are able to get most of the wire in your coils to glow orange, don't try to go fast just take your time and slowly bring the temperature up in the coil until most of it glows orange and simply let it cool off, doing that 2-3 times should be sufficient.

 

[danielpm]

316L should be fairly straight forward, what I think is happening is you're simply not getting the wire hot enough. Torching the wire before you build a coil may be all you need to do, however if there are still hot spots then slowly pulse the fire button until you are able to get most of the wire in your coils to glow orange, don't try to go fast just take your time and slowly bring the temperature up in the coil until most of it glows orange and simply let it cool off, doing that 2-3 times should be sufficient.

I did that, and in fact the coil glowed evenly from inside to outside. But then when I using it I get dry burns, and when I go see the coil it is dark (like if he had burned) in some spots. Will try what you suggested today

 

[spalife]

Good advice from @Froth.

Hope you cleaned the wire with alcohol before building your coil, i.e.,
swipe it with cotton drenched with alcohol to remove some grit & grime.

You will have issues if the SS is not properly warmed up and if the positive and negative posts
are not tight enough.

Since you have vtc-mini, you can try pulsing/firing through SS316L temperature control mode.

This should appeal to your cautious self and assure you that you won't burn out the coil....
you can see the coil changing into rainbow colors based on how hot each wrap becomes.

Start low with 8 watts 120 Degree Celsius and slowly go up to 200 Degree Celcius,
pulsing/firing the coils and tightening the positive and negative posts.

You can also use this method to clean the gunk of the coils and while changing wicks.

 

[danielpm]

@Froth & @spalife

Tried everything you recommended, with contact and spaced coils. After building it, both coils glow perfectly from inside out.. Put some kgd, primed the wick, reassemble the tank (tried in goliath, squape and velocity) and ta-daaaa: dry hit [emoji22]. I just don't now, maybe is the wire, maybe the mod, or probably me.. I think I will go back to kanthal for now, later I will try SS again. It's sad because the few times it worked right (two, I think) I really liked the vape :/

 

[novaracer69]

With ss I have found that dry burning at say 30watts there is no hot spots but if I crank up the watts to 70 I find hotels spots. After working the hot spots out at higher watts it has no hot spots a lower wattage.

 

[SkvLTD]

Got my SS wire today, did notice somewhat of a hot spotting until, as everyone else said, I pulsed the coils enough when they lost the shine and fired perfectly and evenly afterwards. Vapes pretty nice thus far. Dry hits I would pin at the wicking if the coils dry-glow perfectly.

 

[SLIPPY_EEL]

if your getting dry hits then dump the cotton and maybe get some rayon fiber for wick.

 

[Nikea Tiber]

I agree, if you are having issue with dry hits after you have built a uniformly-heating set of coils, you need to look at your wicking.
I also agree that rayon >>> any cotton

 

[Froth]

I agree, if you are having issue with dry hits after you have built a uniformly-heating set of coils, you need to look at your wicking.
I also agree that rayon >>> any cotton

I'll be a third voice, I ONLY use Rayon.

 

[brianc11111]

ill be a fourth voice.... i only use rayon

 

[EverPresentNoob]

Ill add in too, I just started using Rayon... Dont see me going back to my KGD anytime soon. Wrap a nice SS coil, play the drums on the fire button to pulse it up to temp and get it all glowing nicely, pinch it with my Ceramic tweezers and play another drum solo on the button. strum the coil like aguitar, pinch and another drum solo. hot spots are normally gone at this point. prep my rayon and make a scottish roll then wick it up a tad chunky, trim about 80% of the tails off right at the edge of the coil and work the remaining coil into the juice well. apply juice and assemble tank. works damn good.

 

[stylemessiah]

Been using SS in TC for many months, never seen hotspots. I dont even test fire coils anymore, i wrap em, screw them down, wick them and vape.

I like how rayon is apparently like duct tape, solves every problem. Me, ive never had an issue with organic cotton, like ever, tried rayon and found you need to pack more in there as over its use it shrinks. Cotton is far more forgiving and its natural, lasts longer for me