Stainless Steel mesh, Oxide discussion.

[100%VG]

Hello Everyone,

Off Topic, but have you noticed this up top, in the yellow ECF Banner field?

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[mikepetro]

Subscribed....

Can one of you well versed in the chemistry being discussed here take a look at Kanthal DT.

"The grade is characterized by a highly adherent and dense surface oxide that prevents short circuiting between adjacent coil turns."

I am curious what the oxide is on this stuff. If it is the safer lower level oxide, and oxidizing the mesh wasnt necessary......????

 

[Boden]

Subscribed....

Can one of you well versed in the chemistry being discussed here take a look at Kanthal DT.

"The grade is characterized by a highly adherent and dense surface oxide that prevents short circuiting between adjacent coil turns."

I am curious what the oxide is on this stuff. If it is the safer lower level oxide, and oxidizing the mesh wasnt necessary......????

I looked at the page you linked to. There is a bit of marketing going on. All of the Kanthal (A,D,DT) have roughly the same percentages of iron, chromium and aluminum so they all will have the same oxide coating when heated which is mostly Al2O3 which is non conductive and would prevent shorts between wraps.

 

[mikepetro]

Thanks, it is a good marketing pitch, I have been jumping through hoops trying to find it. So far the MOQ has been 50lbs because nobody stateside stocks it.

It did appear to have slightly less Aluminum in it, but all the other specs were almost identical to the D stuff.

 

[Boden]

I think this is really good.

 

[mikepetro]

How does "Passivity" play into this whole oxide discussion, and does "passivity" equal resistance? In other words if I can increase the passivity does it increase electrical resistance? I have been reading on how you can increase passivity using citric acid and EDTA. Just wondering if this could benefit us vapers?

 

[Boden]

How does "Passivity" play into this whole oxide discussion, and does "passivity" equal resistance? In other words if I can increase the passivity does it increase electrical resistance? I have been reading on how you can increase passivity using citric acid and EDTA. Just wondering if this could benefit us vapers?

Not really, Passivation of metal just means making the surface more chemically inert. Which is basically the opposite of torch oxidizing. You could passivate the oxide layer after torching but most of the insulating oxides would be stripped off pretty much negating the process. I've tried it.

http://www.astropak.com/images/technical-papers/pdf-9.pdf

 

[mikepetro]

Thats unfortunate, because I happen to have both citric acid and EDTA in house. I thought of putting a PID temperature controller on a crock pot and cooking up a batch.

Thanks for the link, I have read similar articles, but this is better. None of them really answered the question about electrical resistance though, at least not to my layman brain. I am an Electrical Controls guy, not a chemist.

 

[mikepetro]

Your instincts are good. I'm not concerned with CR fumes it's CR particles coming off the SS mesh after it has been heated to above 800deg F that are troubling. Those particles could be inhaled using the vapor as a carrier. I don't want to describe what happens in the lungs when CRVI is inhaled. If you are curious look it up. I will say that this stuff is so nasty the exposure limit in liquids is 0.02 parts per billion per liter.

I am hearing you on the bad oxides forming and falling into your juice. I noticed heavy juice discoloration on some of my earlier builds. What I evolved to, even before reading this thread, was to torch the SS to redhot, then I run it through my Ultrasonic ( a decent one, not a Walmart toy) for 30-60 minutes to clean it off. Not sure about what it does to the oxides but I noticed little to no discoloration of my juice with this method. When cleaning my wicks I will pull them out and run the rolled wick through the ultrasonic as well.

I am thinking that ultrasonic dislodges the particles, hence the lack of coloration in my juice. Would it be a fair assumption that less coloration equals less free floating oxide particles?

 

[Edible_Funk]

Alright, I finally jumped on the non-oxidized bandwagon. Used to run a no-center-hole thick mesh wick oxidized in my AGA-T, and I only ever saw juice darkening a few times. Not sure if it was the oxides or carmelized sugars, but I figured better safe than sorry. I found the mesh MUCH more difficult to roll tightly and stay rolled, oxidizing definitely helped on that side. As such, the unoxidized wick wasn't able to be quite as thick, so this time I have some play in the wick hole. While I still feel like the coils are not nearly as stable as they used to be (a long vertical burn WILL result in a hot spot after about 8 seconds on this wick, no matter what I do. Granted it's about 1 ohm on a 3.7 "mechanical" pipe mod, so I only need 2 or 3 second max pulls, but still. The oxidized, once I did my coil fiddling, would glow evenly on a dry wick, and with the tank full never even a glimmer! But alas, not the same with the un-oxidized. The first tank and half tasted very off, and I do think I was burning some juice here and there. I have 4 wraps of 30g Kanthal on it, and the top two wraps the wick is blackened underneath. But it is finally seeming to settle in. Of course, as soon as I pull it out to clean or replace the coil I'll have to go through all that again. To clarify, I did not burn the mesh with a lighter or anything, just washed it, rolled it, stuck it in. I usually wrap my coils on a bit or rod, and then sort of screw them onto the wick. I attempted the PetarK method, with no luck. Seems my bits are just the teensiest bit smaller than the wick hole, so the coil is a bit narrower than the wick hole. I suppose the coil could be constricting the wick to a small degree, causing my little problems, but I'm not sure. But as it is now, as long as I'm not too overzealous with that switch, it performs pretty darn well. Just wanted to share my experiences here, and see if anyone had any pointers to get better performance with this whole unoxidized thingy. By the way, when the wick and coil was in place, I kept the thing soaking wet while pulsing on my pipe for a good 30 minutes. At that point it leveled off, but I still get that hot spot up towards the top if I press it too long. (As an aside, first experience with very low ohms and mech mod, love it!) Vape on!

 

[theJuiceNinja]

Pulse when it's dry, before you fill the tank up. Once it glows even then put juice in it

 

[genoxy]

Read through all this and changed all my RBA's to un-oxidised SS mesh

Question, how do you know if your mesh is 316SS or 304SS?

Any updates on the research Boden?

Thanks

 

[zoiDman]

Read through all this and changed all my RBA's to un-oxidised SS mesh

Question, how do you know if your mesh is 316SS or 304SS?

...

There Isn't really a way for person to know Definitively if they have 316 or 304 SS.

You kinda have to go with what the seller says it is. That, and buy from a Reliable source.

 

[genoxy]

Cool, thanks

 

[zoiDman]

Cool, thanks

BTW - If you want to get some Info on a Metals Properties like Alloy Content or Physical Properties, or want to compare 2 Metals, this is a Good Site....

Online Materials Information Resource - MatWeb

MatWeb - The Online Materials Information Resource

MatWeb - The Online Materials Information Resource

 

[learjetz]

I believe the reference to Aluminum Oxides were for "Kanthal" wire.

But many Attys / Cartos / Clearos use Plain Old "NiChrome 80" which contains No Aluminum.


MatWeb - The Online Materials Information Resource (NiChrome 80)

MatWeb - The Online Materials Information Resource(Kanthal A)

BTW - I believe that Most, if not All Kanthal Resistance Wire contain Large percentages of Iron.

Once again, I am unsure of how this May or May Not play a role in the Formation of Bad Chromium Oxides.

Has anyone found or know of any information regarding the oxidation of "NiChrome 80" or other non-kanthal resistance wiring that might be used in our packaged atomizers?

I understand Kanthal is regarded as safe but I am still concerned about NiChrome 80.

I found this page online that might shed light on the NiChrome resistance coil oxidation. I see now this page is also listed on the beginning of this thread.

"Oxidation resistance can be attributed to the formation of a highly adherent protective scale. The adherence and coherence of the scale can be improved by the addition of small amounts of other reactive elements such as zirconium, silicon, cerium, calcium or similar. The scale thus formed is a mixture of nickel and chrome oxides (NiO and Cr2O3). These combine to form nickel chromite (NiCr2O4), which has a spinel-type structure."

It sounds like NiChrome wiring forums a protective layer like kanthal that is composed of NiO and Cr203 which is not regarded as dangerous. Can anyone elaborate or verify this?

 

[Rapture]

Kanthal wire is composed of chromium just like stainless steel is composed of chromium. I think there is actually more chromium in kanthal than stainless steel. I know kanthal is used in blow dryers, and toasters, and blah blah blah. but we dont inhale toasters and blow dryers on a hourly basis.

Does anyone know why stainless steel is being frowned upon using and not kanthal too.

im not worried about heating stainless steel up with a torch or hot coils what im worried about is heating stainless steel MESH up with a torch or hot coils. This stuff is super thin and heats up very quick. I have talked to about 5 welders over the phone and all of them say the same thing. Stainless steel mesh is not very stable and there isnt much research on the subject.

Doesn't it seem like if the wire were using to actually produce the heat is made of chromium and safe then the mesh were heating up thats also made of chromium is safe to heat up too. (not talking torching here) im talking coil heat and dry burns. so basically if the wire gets hot enough to break/melt(release chromium6) then it would break before any damage was done to the mesh. Does this seem logic to anyone. (its hard to grasp the idea)

basically the coil would act as a safety for the mesh. get the coil hot enough to produce chromium 6 and it breaks therefor protecting the mesh. wouldn't you guys think the kanthal would snap or melt before ever getting the mesh hot enough to produce chromium 6. and im talking again about dry burns and hot spot fixing and all that. I know that no one torches there wicks anymore. Some of those hot spots and shorts can get very hot.

 

[Rapture]

In regards to this thread im seeing people using ekowool sleeves around there UN oxidized ss mesh or ss mesh cable. I know it also avoids hotspots too. Is the ss mesh protected from all heat generated from the coils during this setup. for example is the ss mesh still grey and remains in prestine condition after use. Is this a guaranteed way to avoid chromium 6 exposure. It seems to be that way to me. whats your opinions????? please rely

 

[Ill_Rev_J]

Kanthal wire is composed of chromium just like stainless steel is composed of chromium. I think there is actually more chromium in kanthal than stainless steel. I know kanthal is used in blow dryers, and toasters, and blah blah blah. but we dont inhale toasters and blow dryers on a hourly basis.

Does anyone know why stainless steel is being frowned upon using and not kanthal too.

im not worried about heating stainless steel up with a torch or hot coils what im worried about is heating stainless steel MESH up with a torch or hot coils. This stuff is super thin and heats up very quick. I have talked to about 5 welders over the phone and all of them say the same thing. Stainless steel mesh is not very stable and there isnt much research on the subject.

Doesn't it seem like if the wire were using to actually produce the heat is made of chromium and safe then the mesh were heating up thats also made of chromium is safe to heat up too. (not talking torching here) im talking coil heat and dry burns. so basically if the wire gets hot enough to break/melt(release chromium6) then it would break before any damage was done to the mesh. Does this seem logic to anyone. (its hard to grasp the idea)

basically the coil would act as a safety for the mesh. get the coil hot enough to produce chromium 6 and it breaks therefor protecting the mesh. wouldn't you guys think the kanthal would snap or melt before ever getting the mesh hot enough to produce chromium 6. and im talking again about dry burns and hot spot fixing and all that. I know that no one torches there wicks anymore. Some of those hot spots and shorts can get very hot.

From spending the last THREE HOURS or so reading this thread, what I have gotten out of it as regards Kanthal is that heating it to above 1000 C (or possibly the annealing process done by the manufacturer, wasn't clear on that point) produces a thin layer of Aluminum Oxide on the surface, which is regarded as safe/inert. If you heat the Kanthal white-hot, now I'm not so sure what happens then. (not that a person would normally). See posts 37 and 195 by Ulmer for a better explanation, in case you're not OCD like me and haven't read through this whole thread.

Since there is no Al in SS, this oxide cannot be formed simply by heating it, which is why we can't really compare Kanthal to SS as you suggest. (The oxide which protects the SS from rust/oxidation is the inert Cr III, of course.)

I think the test that needs to be done is a measurement of Cr VI in the vapor produced using SS wicks, using different varieties of juice, and over a fairly-elongated period of time. In other words, to mimic as much as possible the actual vaping experience. Just my , fwiw.

EDIT: I think the stainless steel rope/cable (ungalvanized) may be the better way to go, with cotton/ekowool/silica insulation between SS wick and coil. (Or maybe the Petar K method would work with that too?) Apparently it wicks well, and there wouldn't be any fear of micro-hot spots that conceivably could be there with the mesh. That's the way I'm looking to go at this point, when I delve into RBA/Genny-style attys. (Doing lots of research first.)

 

[Rapture]

ok thanks. I have too been thinking about doing the ss rope. I also contacted a metaluallagist** (im very OCD too) and talked to him on the phone for about 15 minutes on the subject of ss mesh and chromium 6. He stated that in order to have chromium 6 we would need to have a perfect environment for it to be created. He stated that even getting stainless steel hot enough to melt it still isnt enough to produce chromium 6. you would need some type of very corrosive liquid in the mix as well. He said that that chances of chromium 6 with what were doing sshould be very minimal. He said that he doesnt even think that chromium 3 would be created. from what I gathered on the phone with him is that there is a very scientific procedure involved to turning chromium into chromium6 that heat alone cannot do.

You should look up a metalluragist and give them a call and get another opoion and share your results.

Now my next question... is nicotine corrosive? he has no idea and isnt a nicotine expert just a metal expert. H