Mulitple Blade plate quench question

[Cstacticalknives]

Hello Everyone, I am going to be to Heat treating four Cpm154 blades soon. I have always done one blade at a time because I only have 2 - 4x3x12 aluminum plates. I would like to do four knives at once. My question is should I set the soak time for the knives longer than the 1 hour time that I have now. Leaving the other knives in the kiln and plate quenching the knives one at a time? Wait 15min and repeat the process with the other knives? My fear is I lose a lot of heat opening up the oven. I know the simplest solution would be to get more aluminum plates but unfortunately I do not have the money for that.
Thanks for your Time
CJ

 

[Stacy E. Apelt - Bladesmith]

Once the soak time at the proper temperature has been completed, it isn't as critical what temperature the drop starts from. The best way to do 4 knives is do the full soak and set the oven on HOLD ( or program the soak for 2 hours). Take one out and do the plate quench. The plates will warm a bit, but yours have plenty of mass. You can stick them in a bucket of ice water to cool them down, but I wouldn't worry about it unless they get too hot to handle comfortably. When the one is done, just pull the next and put in the plates, .... repeat ... repeat..

 

[Cstacticalknives]

Once the soak time at the proper temperature has been completed, it isn't as critical what temperature the drop starts from. The best way to do 4 knives is do the full soak and set the oven on HOLD ( or program the soak for 2 hours). Take one out and do the plate quench. The plates will warm a bit, but yours have plenty of mass. You can stick them in a bucket of ice water to cool them down, but I wouldn't worry about it unless they get too hot to handle comfortably. When the one is done, just pull the next and put in the plates, .... repeat ... repeat..

Thanks you for replying. That is kinda what I was thinking. What would you say is a good rule of thumb regarding the time each knife stays in between the plates?

 

[Stacy E. Apelt - Bladesmith]

A minute or two is more than enough. If you want, use an IR thermometer and check the packet temp after a minute. That kind of measurement and checking the quench tank temp are the two best uses of a non-contact thermometer in the shop. They are pretty useless for reading hot steel above 900F.

 

[Cstacticalknives]

A minute or two is more than enough. If you want, use an IR thermometer and check the packet temp after a minute. That kind of measurement and checking the quench tank temp are the two best uses of a non-contact thermometer in the shop. They are pretty useless for reading hot steel above 900F.

Thanks again Stacy. I really do appreciate your help.