Hello All,
This is my first post here. Relatively new to rebuilding and wanted to share a study I found last night. Apologies if this is not in the correct section.
So, like most people I'm sure, I came across that article about why not to dry burn your coils. Which, being new to rebuilding, concerned me as that's the only way I knew of to check for hot spots/clean your coils. So I went down the rabbit hole, checking out the validity of the claims with my own research (trust issues haha), especially after seeing so many people in the vape community disputing what was being said. I also came across posts claiming Kanthal wasn't safe as it supposedly releases aluminum dioxide etc.
Here's what I found: "The growth of the alumina layer only initiates at temperatures greater than 800°C [14]" and "The surface appears to be smooth when oxidised at 800°C, but with increasing temperature a platelet formation can be seen which at higher temperatures (1100°C) begins to sinter. At 900°C short alumina oxide platelets appear to be formed on the surface which at 1000°C appear to have been transformed into a dense growth of platelets."
But it also seems that aluminum dioxide doesn't even start forming until after 30 minutes at these temperatures. "Although a platelet-like morphology can be seen to be formed on the surface (as early as 0.5 h), they are short and flat during the initial stages of thermal oxidation. .......[This is what lead me to believe that it doesn't start forming before then... so short pulses during dry burning are probably irrelevant ]..........With increasing time these platelets appear to transform into α-Al2O3 nodules which form nucleation centres for further densification and growth of new platelets."
Now I'm no metallurgist. Nor am I an engineer or materials expert. Just a guy whose day job is already to research everything and who overthinks things way too much haha
So, if aluminum dioxide is the concern with Kanthal, this definitely makes me feel better about using Kanthal wire. ( I have no desire to use any metal containing Nickel including SS...SS430 is too hard to come by).
The only side note would be...when dry burning the coils...I personally will only do it at a low wattage and won't let the coil get orange hot ( there are charts corresponding color with temperatures). Especially when you know what temp the alumina forms at. I already know when your vaping though the temps get nowhere near that hot so this all only applies, really, to dry burning.
If anyone is interested in reading the study, here is the link: Growth of Hierarchically Structured High-Surface Area Alumina on FeCrAl Alloy Wires
I did this primarily because there was very little concrete information ( other than peoples opinion) on Kanthal and Aluminum Dioxide growth, also in a scenario similar to dry burning. I wanted to put the info out there so new people like me had it available when they inevitably come across the dry burn controversy. Hope this helps with anyone's concern using Kanthal
This is my first post here. Relatively new to rebuilding and wanted to share a study I found last night. Apologies if this is not in the correct section.
So, like most people I'm sure, I came across that article about why not to dry burn your coils. Which, being new to rebuilding, concerned me as that's the only way I knew of to check for hot spots/clean your coils. So I went down the rabbit hole, checking out the validity of the claims with my own research (trust issues haha), especially after seeing so many people in the vape community disputing what was being said. I also came across posts claiming Kanthal wasn't safe as it supposedly releases aluminum dioxide etc.
Here's what I found: "The growth of the alumina layer only initiates at temperatures greater than 800°C [14]" and "The surface appears to be smooth when oxidised at 800°C, but with increasing temperature a platelet formation can be seen which at higher temperatures (1100°C) begins to sinter. At 900°C short alumina oxide platelets appear to be formed on the surface which at 1000°C appear to have been transformed into a dense growth of platelets."
But it also seems that aluminum dioxide doesn't even start forming until after 30 minutes at these temperatures. "Although a platelet-like morphology can be seen to be formed on the surface (as early as 0.5 h), they are short and flat during the initial stages of thermal oxidation. .......[This is what lead me to believe that it doesn't start forming before then... so short pulses during dry burning are probably irrelevant ]..........With increasing time these platelets appear to transform into α-Al2O3 nodules which form nucleation centres for further densification and growth of new platelets."
Now I'm no metallurgist. Nor am I an engineer or materials expert. Just a guy whose day job is already to research everything and who overthinks things way too much haha
So, if aluminum dioxide is the concern with Kanthal, this definitely makes me feel better about using Kanthal wire. ( I have no desire to use any metal containing Nickel including SS...SS430 is too hard to come by).
The only side note would be...when dry burning the coils...I personally will only do it at a low wattage and won't let the coil get orange hot ( there are charts corresponding color with temperatures). Especially when you know what temp the alumina forms at. I already know when your vaping though the temps get nowhere near that hot so this all only applies, really, to dry burning.
If anyone is interested in reading the study, here is the link: Growth of Hierarchically Structured High-Surface Area Alumina on FeCrAl Alloy Wires
I did this primarily because there was very little concrete information ( other than peoples opinion) on Kanthal and Aluminum Dioxide growth, also in a scenario similar to dry burning. I wanted to put the info out there so new people like me had it available when they inevitably come across the dry burn controversy. Hope this helps with anyone's concern using Kanthal
