Recommendation? Cryo treatment help

[hathegkla]

I'm in the middle of my first cryo. I picked up a dewar full of liquid nitrogen and I don't have a good container that's long enough. So right now I'm suspending the knives from a piece of bailing wire into the dewar. The LN2 doesn't completely cover the blade, it's maybe 3/4 of the way in. my question is does this really matter? I'm assuming the blade is still very cold all the way through I just wanted to check and make sure I'm not doing anything terrible.

 

[A.McPherson]

Generally, if your whole knife is inside the dewar, it'll get to the same temp... Within reason of course.

The larger your container the larger the temp gradient inside the container.

 

[hathegkla]

Generally, if your whole knife is inside the dewar, it'll get to the same temp... Within reason of course.

The larger your container the larger the temp gradient inside the container.

ok great, thanks! after a minute or two the temperature seemed to equalize and the LN2 stopped boiling/steaming. it's a 6 liter dewar, I think that's enough thermal mass. I closed the lid so hopefully I'm ok. I don't think my laser thermometer goes low enough to test it though.

 

[Stromberg Knives]

I was curious about this when I first got my dewar with LN2 (a Taylor Wharton 25 liter). So I measured the temperature just below the neck of the dewar when it was only a couple of centimeters (maybe an inch) of LN2 left. I was surprised to find the temperature to be exactly the same whether it was full or almost empty.