Stainless Steel (dry burn)

[mekks082]

I tried Ti and disliked not being able to dry burn, and also the constant popping.

Picked up some 24g and 26g 316L stainless today. Can stainless be dry burned? My coils seem to get gunked up every other day. I wash/dry burn/rewick.

btw I will be running this on a vtc mini with SS mode.

 

[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.

 

[fishwater]

I just did a new build on my Bachelor with a spaced 12 wrap coil that is outperforming my previous spaced 6 wrap or contact by a substantial margin on my new DNA 200, instantly made me a believer in spaced vs contact this weekend.

 

[fishwater]

Agreed, I tried the screw method & blah, not for me. Wrapping a typical contact coil & then pulling it does the trick perfectly every time.

 

[Rockwell222]

I've heard mixed things on dry burning SS but it seems like it's alright. And with the titanium I think you had a not so good quality titanium because ti is all I've used for 8 months and everyone that try's out my tanks and rdas comments on the clean taste. The popping your talking about is gonna be your wicking most likely and not the ti. If it's wicked a little loose you'll get popping on any wire.

 

[Shigura]

I tried Ti and disliked not being able to dry burn, and also the constant popping.

Picked up some 24g and 26g 316L stainless today. Can stainless be dry burned? My coils seem to get gunked up every other day. I wash/dry burn/rewick.

btw I will be running this on a vtc mini with SS mode.

Yes one can dry burn stainless steel wire as it can be used both in power and TC applications. Which is why its an ideal type of wire for this very fact. Using SS430 myself I will dry burn it to clear the gunk and then re-wick.

 

[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).

 

[fishwater]

And you are running on TC with contact SS coils?

I read and watch many reviews all claiming for TC, all type coil builds must spaced for accurate TC reading. But of course these are RTA builds.

I've run plenty of contact coil builds on TC with Ti & SS, it's only Ni200 that you must use spaced coils with. There is a lot of preference lately to spaced builds for TC but again unless you're using Ni200 you can do whatever you want, spaced or contact.

 

[ShowerHead]

I have some Crown tanks and use 28 Ga SS430. I only do TC nowadays.
At first I did spaced coils. Worked fine, but kind of uneven. Then I was inspired by someone to do a contact coil.
A 3mm coil worked a treat. I pulsed it and even after a cleaning with alcohol (or maybe because of) there was a little curl of smoke come off it. Strum it to get an even inside out glow. Wick it. Vape.

I've not seen any difference in taste except possibly a positive one. Thanks to @Froth for letting me know that I can just pulse the coils until they glow properly.

In short, I have done these coils both ways and have several tanks with 'old' coils to compare to. No odd taste whatsoever. Getting a contact coil right is much easier than playing with getting the coil spaced evenly. Plus, when I wick them, no worries about the spacing changing.

 

[Nikea Tiber]

The most critical element of the process Froth described with pulse-firing is the even distribution of heat throughout the coil to ensure the formation of the (non-conductive) oxide layer across the entire exposed surface of the coil.
This is necessary when you build contact coils so the current doesn't short past coils, dropping the coil resistance.
Firing at high wattages will heat the coil faster, however if a coil is shorting, the portion of coil receiving energy might heat quickly enough to melt, so wattage used to pulse-fire is really a matter of personal preference and what you are comfortable your reflexes can handle.

 

[BillW50]

Getting a contact coil right is much easier than playing with getting the coil spaced evenly. Plus, when I wick them, no worries about the spacing changing.

I have no problems making spaced coils. The easiest way for me is wrapping a compressed coil and a really tight compressed coil. Then I stretch them out like a spring. They all stretch out evenly and perfectly (thus why wrapping really tight makes this work this way). Nor have I found any problems with the wicking moving the spacing. Although I don't use any wire smaller than 28g, but I do the same for soft Ni200 28ga wire. Some people found wrapping around a screw works for them. That probably works too, as I have never tried it.

 

[Nikea Tiber]

If you were the size of a steam molecule, what we percieve as contact coils wouldn't be contact coils at all. There is enough space between the wraps that it doesn't pose a significant impediment to vapor escaping the wick and coil.
I feel that the advantages to compression wound contact coils are that they ramp up more quickly as the coil heats itself more efficiently with its own radiant heat, and (at least I feel) it is easier to place the coil more precisely in the atomizers airflow.
I try and build my coil size to the airflow inlet dimensions of the RDA I'm using. Once I've built the coil and placed it sometimes I'll put the mandrel back on and space the coils a little, it helps with gunking on hotter builds.
Unless it is ni200, it is all personal preference really. As long as it gets you nicotine and flavor and doesn't physically blow your face off, there is no wrong way to do it.

 

[J Wo]

Oh cool, and good to know. I love coming to the ECF, I'm learning new things about vapeing every time.

 

[ThunderDan]

Ni is lower resistance than Ti. Which is SS closer to? Ni or Ti?

The resistance is closer to Ti.

 

[AtmizrOpin]

well I don't do spaced wraps. How do you fuse them together? and what is the best ss type for vaping? And why? I am new here? Sorry for bad english.

for SS coils to work best for temperature control, spaced wraps are a must. a good SS for TC is 430. it has a higher TCR than the other SS's that are available. i use 316L for my SS TC builds. it has a low TCR value but still works for TC. if you're not fimilar on what a TCR is, do some reasearch. Temperature Coeffecient of Resistance (TCR). i build a slightly spaced coil, dry fire it to make sure there are no hot spots and it glows from the inside out. you mentioned you're new here, so i'm assuming you have a mod that'll do SS TC. if not you can still run SS in power mode.

 

[Nikea Tiber]

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.

 

[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.

 

[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.

 

[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.