Stainless Steel (dry burn)

[sofarsogood]

With the exception of ni200, you don't need to build spaced coils for tc provided you dry-pulse then to ensure consistent heating throughout the coil; a hot spot or partial short through a coil will throw off the atty resistance, rendering TC useless.

I always try and fit coil size to the atomizers air inlet; it seems to reduce spitting on atomizers prone to spitting and I feel it reduces coil ramp up time a bit, as more radiant energy is transfered to coil vs saturated wick.

To answer the question about stainless steel rotowound (clapton) coils, I've ran an El Cabron with 26 awg 316sl SS core, 32 awg kanthal wrap. TC works just fine, the extra coil mass need a wattage adjustment to compensate for the ramp-up so you will drain your battery a bit quicker. I know I'm not alone feeling that "clapton" coils don't offer any flavor difference or vapor density vs a naked wire coil. At a certain point, the main factor to vapor production is the coils radiant heat output to the volume of the wick, because juice vaporization is happening in the wick, not on the surface area of the coil.

Can you help me with this one? My evic vtc mini starts to singe dry cotton when it's indicating 340 degrees. This happens with 28 guage 316 stainless, 1.25 ohm (3mm inside diameter, 11 wraps). Can I use the tcr setting to correct the temperature reading so it indicates 420 degrees at that point? How do I determine the tcr value to get that done? Is there some other factor I might be overlooking?

 

[Wingsfan0310]

Providing your connections are all good, it seems like you are using a TCR value that is to high. The TCR for 316 SS is .00092

Cheers,
Steve

 

[ShowerHead]

With the exception of ni200, you don't need to build spaced coils for tc provided you dry-pulse then to ensure consistent heating throughout the coil; a hot spot or partial short through a coil will throw off the atty resistance, rendering TC useless.

I heartily agree with this.
I had, for some reason, always built TC coils with spaced wraps.
I recently tried a contact coil, strummed it to get a nice inside out glow with no hot legs or spots.
Made a big difference on my Crown tank.
Why did I try this? To get a larger diameter coil to be able to get more cotton in the Crown. Problem with leaking.
28 GA SS430, 8 wraps, 3mm ID, comes in at .95 ohms. Vapes really nice. And so far, no leaks.
Just remember what Nikea said, do the dry burn and work out an even inside to outside glow.
One of the nice things about SS, the ability to treat it as you did Kanthal.

 

[Walleytroll]

I heartily agree with this.
I had, for some reason, always built TC coils with spaced wraps.
I recently tried a contact coil, strummed it to get a nice inside out glow with no hot legs or spots.
Made a big difference on my Crown tank.
Why did I try this? To get a larger diameter coil to be able to get more cotton in the Crown. Problem with leaking.
28 GA SS430, 8 wraps, 3mm ID, comes in at .95 ohms. Vapes really nice. And so far, no leaks.
Just remember what Nikea said, do the dry burn and work out an even inside to outside glow.
One of the nice things about SS, the ability to treat it as you did Kanthal.

What wattage would you use to dry burn a single coil in stainless? I've heard that overheating it can cause the creation of some nasty unwanted metals. I just ordered some 316 SS and I'm about to start making coils, and I would really love to be able to dry burn and re-wick. Do you use wattage mode or temp control to dry burn?

 

[ShowerHead]

What wattage would you use to dry burn a single coil in stainless? I've heard that overheating it can cause the creation of some nasty unwanted metals. I just ordered some 316 SS and I'm about to start making coils, and I would really love to be able to dry burn and re-wick. Do you use wattage mode or temp control to dry burn?

Sorry, I use a Coil Master Tab 521 and just use the Fire toggle.
I'll say that power mode would be the one to use. Start low and increase until you get a glow. Shouldn't hurt anything that way.

 

[Nikea Tiber]

Can you help me with this one? My evic vtc mini starts to singe dry cotton when it's indicating 340 degrees. This happens with 28 guage 316 stainless, 1.25 ohm (3mm inside diameter, 11 wraps). Can I use the tcr setting to correct the temperature reading so it indicates 420 degrees at that point? How do I determine the tcr value to get that done? Is there some other factor I might be overlooking?

The mass of your coil is quite large. Try reducing your wraps/resistance by half and see how it works out.
FWIW, the "test" to see if your mod will burn dry cotton doesn't prove anything. The phase change from juice to steam is the biggest source of energy loss in the coil, the ability/inability to singe dry cotton doesn't give you any real useful information on the efficacy of a mods temp control.

What wattage would you use to dry burn a single coil in stainless? I've heard that overheating it can cause the creation of some nasty unwanted metals. I just ordered some 316 SS and I'm about to start making coils, and I would really love to be able to dry burn and re-wick. Do you use wattage mode or temp control to dry burn?

Depends on coil mass. Lower is beneficial because a hot spot on a coil can sometimes overheat very quickly.
As for hexavalent chromium and other possible nasty substances; they tend to happen at welding temperatures.
Steel changes color predictably as it heats, I perform my dry burns in a darkened room to visually gauge when to cut the power and let the coil cool. There are probably steel temperature charts available online for use in tempering. I don't let the coil build past bright cherry, once you hit straw cutting the power is best, IMO.

 

[Wingsfan0310]

When I dry burn SS 430 I use wattage mode at 15 watts. I'm not trying to start a forest fire, just get it to glow. I'm using dual coils, 28ga, comes out to ~.3 ohms. Nothing crazy, just 7 wrap horizontal coils (2-2.5mm).

 

[sofarsogood]

The mass of your coil is quite large. Try reducing your wraps/resistance by half and see how it works out.
FWIW, the "test" to see if your mod will burn dry cotton doesn't prove anything. The phase change from juice to steam is the biggest source of energy loss in the coil, the ability/inability to singe dry cotton doesn't give you any real useful information on the efficacy of a mods temp control.

I've been assuming that temp control heats the coil as fast as max watts allows regardless of coil mass or initial resistance.

 

[KenD]

I've been assuming that temp control heats the coil as fast as max watts allows regardless of coil mass or initial resistance.

More mass = more power returned to heat up

Sent from my M7_PLUS using Tapatalk

 

[Walleytroll]

Depends on coil mass. Lower is beneficial because a hot spot on a coil can sometimes overheat very quickly.
As for hexavalent chromium and other possible nasty substances; they tend to happen at welding temperatures.
Steel changes color predictably as it heats, I perform my dry burns in a darkened room to visually gauge when to cut the power and let the coil cool. There are probably steel temperature charts available online for use in tempering. I don't let the coil build past bright cherry, once you hit straw cutting the power is best, IMO.

Thanks, I'm getting my SS 316L today and I'll try it out tonight. From what I've read, the heating is just enough to detect whether the coil is hot spotting and that it glows evenly from the inside, IE kanthal builds. I may go with a spread coil first just to get used to building with stainless safely.

 

[Nikea Tiber]

I've been assuming that temp control heats the coil as fast as max watts allows regardless of coil mass or initial resistance.

It will heat according to your wattage setting unless you have a mod that has different preheat modes.
A higher mass coil retains more heat energy and does not react (in both heating and cooling off) as quickly as a smaller coil. The extra heat it retains could be part of your problem with scorching your wicks, the other being no TC mod is designed to protect completely dry wicks.

 

[Akuma888]

Can I ask for Clapton SS built to be use for TC, does it need to be spaced?

 

[BillW50]

As for hexavalent chromium and other possible nasty substances; they tend to happen at welding temperatures.

I used to love SS, but no more after today. I dry burned my Crown RBA SS316L and I got a horrible smell. Tried again thinking maybe some juice was being fried off or something and it only got worse. Well I thought maybe it will go away at vaping temperatures. Nope, tasted like crap. Tossed that coil out and wrapped a Ni200 coil and all is well once again.

 

[HDMontana]

Weird, I have dry burned my SS Clapton's with no issues. Rewicked them and good to go.

HD

 

[BillW50]

Weird, I have dry burned my SS Clapton's with no issues. Rewicked them and good to go.

Same here. I had no problems with dry burning SS before. Then today it is like suddenly in a flash the SS changed into something else. If I ever use it again, I am not going to dry burn it anymore.

 

[fishwater]

Funny you mention this, I've noticed an off taste after I dry burn SS lately. I'm using UD SS 316L, at first I thought it was the juice but then I noticed it wth the same juice in the tank after the dry burn. I wasn't sure if it was my cotton bacon or not but now you guy's have me wondering if it's the SS & maybe I shouldn't dry burn. The off taste does go away after a few pulls but it's definitely there.

 

[Akuma888]

What is the wattage to do a dry burn?
It should be done in power mode right?
Does dry burn requires with new coils setup to remove hot spots?
I'm am about to try wrapping SS316L coils too.

 

[fishwater]

Mystery solved, just did two spaced coil builds with the same wire on two different tanks. Didn't pulse or dry burn & there is no off taste at all. Obviously I was getting something (probably completely unhealthy) on my coils from dry burning. I learned my lesson, no more dry burning SS for me.

 

[Froth]

I'm not a temp control guy but I've been a believer in SS for nearly a year now, so I feel I could pass on what I have learned over that time.

Not only do I always dry burn SS I believe a dry burn is essential to getting a properly glowing contact coil that heats from the inside out and performs the best it can. The reasoning for this is oxide layer formation, like Kanthal the first time you heat up SS to a glowing orange state and let it gradually cool it will form an oxide layer on the surface, that oxide layer is essential to a long lasting good performing SS contact coil build IMO. One thing I notice with SS through dry firing/pulsing is that if you had hot spots in your coil they will eventually work themselves out if you pulse fire it a half dozen times letting it cool completely between each fire, this is because the oxide layer is forming on the surface which insulates the wraps from one another preventing the "arc" hot spot.

What wattage would you use to dry burn a single coil in stainless? I've heard that overheating it can cause the creation of some nasty unwanted metals. I just ordered some 316 SS and I'm about to start making coils, and I would really love to be able to dry burn and re-wick. Do you use wattage mode or temp control to dry burn?

This is not the first time I have come across this belief with the use of SS wire, I assume you meant Hexavalent Chromium by "nasty unwanted metals" as that is the only real one of concern with SS. However, that will only be created in excess of 3000°F, the main concern for areas of exposure would be an industrial welding environment or a large metal foundry where there is a large mass of SS being super heated for a long period of time. So, beacause of the required temperature to produce anything harmful you would have to be inhaling across white hot glowing coils as they were about to "pop" from heat stress to even begin to have a chance of inhaling anything harmful, SS is not going to release anything harmful at dry burn temperatures and even if it could get hot enough to do so the wire is such a small mass of SS the risk is reduced even further.

For the past year I have used 304 SS specifically and I do use a large gauge of 22G, I also build very large diameter coils ranging from 3mm to 4.5mm ID. With a brand new build I dry fire at roughly 100W until they are glowing orange hot and even. When I'm cleaning off a build I will dry fire my coils to glowing orange and then run them under a small stream of cold water which causes all of the gunk to slide right off my coils. After that I just re-wick and go, have not noticed any flavor changes or issues with 304 SS and I have one build that is over 5 months old, probably been dry burned 25 times and still going.

 

[Akuma888]

I'm not a temp control guy but I've been a believer in SS for nearly a year now, so I feel I could pass on what I have learned over that time.

For the past year I have used 304 SS specifically and I do use a large gauge of 22G, I also build very large diameter coils ranging from 3mm to 4.5mm ID. With a brand new build I dry fire at roughly 100W until they are glowing orange hot and even. When I'm cleaning off a build I will dry fire my coils to glowing orange and then run them under a small stream of cold water which causes all of the gunk to slide right off my coils. After that I just re-wick and go, have not noticed any flavor changes or issues with 304 SS and I have one build that is over 5 months old, probably been dry burned 25 times and still going.

Thanks for the info Froth, so what happens if I do not a 100W power to pulse my coils, is it essentially you just need to pulse the coils glowing orange, cool down process to make it long lasting?

Are your SS built coils spaced or compact?