Heat Retention Fallacies, The Secret To Proper Seasoning Revealed

You want to know the secret to proper seasoning?

Paint the oil on at a fairly mild temperature. Dropping larger amounts on super heated surfaces is less effective as the material tends to vaporize before it has an opportunity to season.

The reason most people have a bad experience with brand new titanium is because they get it way too hot. Titanium and glass have relatively low thermal conductivity levels when compared to materials such as aluminum, steel, or copper. Low thermal conductivity means that it takes longer for the energy to travel through the material, therefore materials with low thermal conductivity also take a longer amount of time to lose that energy, or, cool down.

Borosilicate glass, and quartz alike, have relatively low thermal conductivity values; their values are 1.14 W/(m·K) for borosilicate and 1.3 W/(m·K) for quartz. Pure titanium, in comparison, has a value of 21.9 W/(m·K). What does this mean? Well, for one it means that everyone who told you titanium retains heat better than quartz or glass was wrong, myself included as I have said it in the past without researching it (egg all over my face). Titanium merely heats up faster.

Its easy to see why we could incorrectly assume titanium retains heat longer than glass or quartz because with daily use we notice the titanium gets much hotter after 30 seconds of heating than the glass does. This isn’t because the glass couldn’t retain the heat, its because the glass wasn’t heated long enough to get to temperature in the first place due to its low thermal conductivity value.  Look at those numbers again, you would probably want to torch glass or quartz at least 5x longer if not more to reach the same temperature levels you reach with titanium. So the fallacy we have heard so often that “titanium retains heat better than boro or quartz” needs to be corrected to “titanium has a higher thermal conductivity value than boro or quartz”.

I explained all of that so that we could get back to discussing seasoning.

People get brand new titanium way too hot. The thermal conductivity allows it to get hot very quickly and it can still retain heat very well as many of you already know. Dont let the 21.9 value fool you into thinking it cant retain heat, its still relatively low when compared to other high conductor metals like aluminum (237). This means you will need to allow a significant amount of time for your nail to cool before applying your seasoning material.

For the seasoning process to work best the metal needs to be cooled below the materials leidenfrost point. The leidenfrost point may be slightly different for each material being used and also the vaporization surface is an actual variable. In a study to determine waters leidenfrost point a group determined it to be at 339.8º F for a polished surface, and 505.4º F for a rough surface. This means that with a brand new ti nail there is going to be a much lower temperature point at which your material will experience the leidenfrost effect. This effectively prevents it from being able to season the titanium. The only effect it seems to yield is slightly roughing the surface.

That group study remarked

“Surface deposits left from previous drops tend to serve as vapor nucleation sources when making contact with newly deposited drops. It is intuitively obvious that surface contamination from previous drops will act to increase the roughness on a polished surface”.[source]

So what temperature should you apply it at for best seasoning? Its hard to say an exact number as I haven’t conducted thorough experiments with controlled variables. Water boils around 212º F depending on atmospheric pressure, it’s critical point is 705º F, and it was experiencing the leidenfrost at temperatures as low as 339.8º F on a polished surface. If I were to guess I would say essential oils probably have a slightly higher leidenfrost point than water, but that is only a guess, and I would assume painting and spreading oil on a brand new nail around 400-700º F will season it much more effectively than temperatures exceeding that.

tl;dr

Titanium doesnt retain heat longer than quartz or glass. You’re getting it too hot when you season it.