Recommendation? Hobby knife maker Heat treatment issues

S

Shade Tree Knife Maker

Joined
Jan 28, 2023
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I have been heat treating s90v in gas forge with a thermo couple. I have a few issues not sure how to fix them. Issue one I have is I am getting something like bacon edge but it’s more of edge warp than bacon edge I used .010 edge thickness it was the worst. I bumped it to.020 still getting some of it. I am grinding a full flat grind and a distal
Taper I normally get a slight bend towards the tip with the .020 I can get most of that out if it’s slight. I assume I could correct some of this by leaving edge thickness at .030.
I have a friend that has tested my knives they are running 59 to 61 I was running the temp on my forge at 2075. I moved it up to 2150 thinking I would get a little higher Rockwell. My foil got really stuck to the blade had to grind it off. One area of the foil was broken down almost like it was over heated. My foil was rated for 2200 degrees I think my thermocouple may be reading a little lower than actual temperature? Any thoughts on this would be appreciated.
 
Shade Tree Knife Maker said:
I have been heat treating s90v in gas forge with a thermo couple. I have a few issues not sure how to fix them. Issue one I have is I am getting something like bacon edge but it’s more of edge warp than bacon edge I used .010 edge thickness it was the worst. I bumped it to.020 still getting some of it. I am grinding a full flat grind and a distal
Taper I normally get a slight bend towards the tip with the .020 I can get most of that out if it’s slight. I assume I could correct some of this by leaving edge thickness at .030.
I have a friend that has tested my knives they are running 59 to 61 I was running the temp on my forge at 2075. I moved it up to 2150 thinking I would get a little higher Rockwell. My foil got really stuck to the blade had to grind it off. One area of the foil was broken down almost like it was over heated. My foil was rated for 2200 degrees I think my thermocouple may be reading a little lower than actual temperature? Any thoughts on this would be appreciated.
Click to expand...
You’ll probably have better luck getting an answer in this section.

https://www.bladeforums.com/forums/shop-talk-bladesmith-questions-and-answers.741/
 
S90v needs to be held at temp for around 20 minutes, give or take? Unless your gas forge is PID controlled I don’t think your temp will be stable enough to ht anything except one of the very basic steels with any degree of accuracy (1084,15n20, and a couple others).
Grinding thin pre-ht is asking for bacon edge/warp issues and the more complex steels and higher temps and long soaks at temp increase the potential problems.

A hardness test (good numbers), is not an indication of a good ht.

Filling out your profile can help us help you. We don’t know where you are starting experience-wise at this point.
Good luck and welcome!
 
With S90V, or any other high carbide/wear resistant steel, I grind and hand sand to at least 320 grit pre-HT, taking the edge to .015. But I also send mine out for HT to a pro with accurate, repeatable results, and have never had an issue.
 
I don’t know how to use this forum yet I am not the most tech savvy but I will try to fill out my profile when I figure it out. So here is a little info if this helps. i have been hobby making knifes for a couple years but i have only made 12 complete knives and about 3 or 4 more i have completed for other people who had half finished knife projects….. So I consider myself very new at the knife making hobby. I started this to get good enough to make myself a great set of kitchen knives. I sent my first knife to a heat treatment company three years ago it was D2 it cost me about 40 dollars. The Heat treatment was great it just took about 6 weeks and to me was expensive. I tried a place called Texas Knife supply they heat treated one knife made out of elmax and 4 out of s90v. I followed the instructions on how they wanted it labeled but they ended up heat treating them all as elmax so the elmax was fine. The s90v came in around 50 Rockwell. So I called them explained my test results and sent them back and they fixed for free. They Came back around 63 Rockwell. They had a quicker turnaround time and with doing a batch of 5 it dropped the cost down to 20 Dollars a knife this includes shipping cost. So the first place would have also been a little better price by shipping a batch versus a single knife. I made a few knives out of 1084 using a crumby backyard setup it was cool it got me thinking of trying to do something different with the stainless steels. So I got a two burner mr forge with some fire brick I blocked off the back and inserted a thermocouple. Inside the forge the thermo couple is surrounded by a piece of 2x2 tubing pushed to one side away from the burners. I put my knives in when it reaches 1500 degrees and then run it up to desired temp I close off the front of the forge with more fire brick leaving a small opening. I can hold the temp in about a ten to 20 degree window. I was thinking that would be good enough for heat treatment but maybe I was wrong. I seen this guy on YouTube luong la do a heat treatment with weed burner I asked him a few questions he was doing some really interesting stuff but sounded like to me I was going to get a ok heat treatment with my setup. I understand it’s not ideal and maybe I should just do 1084 until I get better at it. I can then Make some s90v stuff for my self and send it out for heat treatment. I like 1084 type steel I just don’t know many who do and the knives I make I have friends that buy them for twice the cost of materials. It is not much just enough so I get to experiment for free just costs my time. I am not planning on making a 1,000 knives just make a few for myself and probably make a few per year for friends and family. Sounds like I may not be going down the right path that’s why I jumped on this forum for some advice.
 
there are some forum members that do heat treating as a service, and do it very well at reasonable cost...
JTknives JTknives

Heat Treating

I offer heat treating to forum members, no minimum quantity. If you have one or ten blades I can do it. All the prices are in my signature as well as the order sheet you fill out when you send me your blades. I do not have a bulk price because each blade is handled one at a time. There are a few...
www.bladeforums.com www.bladeforums.com

that was one that comes top of mind.... you'll see that many members have been happy with his results
:)

otherwise, get into some 80crv2 ... its very similar to 1084, but better imho - while costing about the same - and simple heat treating approach is the same as 1084
 
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Fill out all the info honestly and with any specifics that will help us know a bit about you and your skills levels.
 
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