Joel K

Yes, thanks I actually put a piece of brown paper bag in this one... but had the leaky pouch in spite of it.

Thanks for the feedback everyone!

I did clean it thoroughly with acetone before bagging it and used paper towel to put it in the foil pouch.

I believe it was a leak in the foil pouch...so scale from oxygen during heat treat.  It did not polish off with a scotchbrite wheel hence my concern and post here.

Took it back to the grinder which eventually cleaned it up.  

Will have to perfect my pouch sealing technique.   Double folded edge and sqeezed edge tight in a vise...  

Have heard of a scale preventing liquid, Espon,  that works up to 1280c but can't find a source to buy. 

Flux burns away at too low a temp.

Thanks!

J

Thanks for relocating my post here Steve.  The Temps I used are from Evenheat website for knife heat treat.  I'm still curious about cause of black blotch....maybe a bad spot in steel??

Shooting for 55-60 HRC file test.  It's passing the hardness test, except maybe the one little blade edge spot in the middle of the dark spot on left.  The 440C heat treat guidance I used was from Evenheat to 1850f 20 minutes, air quench to no less than 125f then temper at 220f 2 hours, air cool then final temper at 200f 2 hours.

Still wondering if I did something wrong or is this a metal flaw in the piece of 440C.

Thanks

Joel

Heat treated in an evenheat oven wrapped in SS foil at 1850 for 20min. Air cooled to about 150 then tempered 220 for 2h then 200 for 2h.  

The darkness on the left isn't buffing out... and edge feels a bit soft to the HRC test files.  Is it a prob with the steel or prob with my heat treat?

Thanks

Joel

Hello fellow blacksmiths!

Came across this anvil for sale and need help identifying it.

Owner claims its a Kohlswa 517# anvil and it has markings that may match but it looks very different to me than images of other Kohlswa anvils out on google.  Any help is greatly appreciated!

Joel

PS trying to get images posted...