Where to buy a wide mouth LN dewar that doesn't break the bank?

JG Custom Metal Works

JG Custom Metal Works

Joined
Nov 27, 2013
Messages
1,626
So I have my Evenheat oven coming in in a week or two and I figured I should probably get a LN dewar for cryo. I searched through a ton of threads on here and other places on the net before starting this thread. It seems a lot of the sources mentioned in those threads have dried up.

I thought about doing the dry ice/acetone slurry but I guess there's some steels that need to get to lower temps than what that reaches. I figured, if I'm going to the trouble of getting an oven and everything to heat treat in house, I might as well get a sure shot cryo setup too.

I've searched a ton on Ebay and other places for dewars and it seems that the main drawback is the diameter of the mouth. I see a lot of them that are just under 2". It would be nice to have a mouth that was at least 2.5" so I would have plenty of room to do 2" chef knives and maybe choppers/comp cutters.

I have found some with a wider mouth but they're priced around the $500-$800 range and I'd like to not have to spend that much for one. Hell, I'd like to only spend $200 but I realize this is one of those "buy once, cry once" type of deals. So I have a budget of around $400.

The longest knives I'll probably do will be 15"-16" OAL with a 10"-11" blade.

Anyone know where I could find one for a decent price?
 
Last edited:
When I was in college, back in the dark ages when students could buy LN by the pound from the university stores, we would go collect it in a cooler. Plastic or styrofoam, both worked, and although it evaporated much faster from the cooler than a dewar, you could keep enough in the cooler to get stuff done. I remember starting with 20 lbs, and still having about 10 lbs in the cooler 3 hours later. Of course it depends on how long you need to keep the blade in the LN, and you do have to be careful not to shatter the cooler. But unless you are always going to be making blades wider than 2", it might be less expensive to go with a narrower mouth Dewar, and have a good cooler for treating the wider blades
 
I searched for a while and finally ended up renting one. It's 50 cents a day at airgas. Depending on how you work, you could just go rent it for when you are doing a batch. It's actually pretty convenient


Sent from my iPhone using Tapatalk
 
I have an MVE 20 liter tank and it has some type of safety blowoff valve thing that the one on Amazon doesn't have. I've used LN quite a bit in restaurants, that's why I originally got the tank. The opening is 2in.
 
I wonder what the safety blowoff valves function is? I wonder if I'd be okay without that safety measure? Aside from refiling it and driving home, the Dewar will be stationary.

Any opinions you guys could give me on this Dewar would be very very very much appreciated as I have to let him know tonight if I want it. It's $722 from Amazon new so I would think paying $315 for a new one would be good right? I guess his company won it at an auction as part of a larger "lot." It's brand new, they just don't have any use for it.

I'm sure on the exterior deminsions but I wonder how bug the inside is... If it's 23in tall, I should be able to do 15in blade at least, right?

Again, anyone who could let me know what they think before tonight would be awesome
 
I don't see much use for the over-pressure valve since the plug is not air tight... ok, at least for my 20L dewar - https://www.thermofisher.com/order/catalog/product/CK509X2#/legacy=thermoscientific.com

Got my dewar off the 'bay for slightly less than $500. Search for 2nd hand lab equipment shops out there, many have dewar at reasonable price.

Blade width is more critical than length - mine dewar inside diameter is only 2" wide, so can't dunk/soak wider blades. I can always pour some LN2 into a styrofoam canal for cryo dunk a blade wider than 2".


JG Custom Metal Works said:
I wonder what the safety blowoff valves function is? I wonder if I'd be okay without that safety measure? Aside from refiling it and driving home, the Dewar will be stationary.

Any opinions you guys could give me on this Dewar would be very very very much appreciated as I have to let him know tonight if I want it. It's $722 from Amazon new so I would think paying $315 for a new one would be good right? I guess his company won it at an auction as part of a larger "lot." It's brand new, they just don't have any use for it.

I'm sure on the exterior deminsions but I wonder how bug the inside is... If it's 23in tall, I should be able to do 15in blade at least, right?

Again, anyone who could let me know what they think before tonight would be awesome
Click to expand...
 
You must log in or register to reply here.
Back
Top