when to heat treat, before after grind?

[lobo9er]

Bought an anvil from harbour frieght and pounded out a couple knives over the last couple weeks. It has been a really easy way to spend a saturday afternoon and days off here and there. So far it has been pretty easy hobby to get into, made a forge out of some bricks i had laying around and used a little charcoal and downed limbs for heat. so far so good, but now what? should I grind the blades down before heat treating or after? I am thinking after but wondering how you guys do it. And also how do you guys heat treat? There are some videos on youtube that I just found but none are all that great, is there any "how to" vids you guys and or gals can recommend?
any help would be great and i will try to figure out how to post some pics in case anyone cares to see the progress.

 

[rcmodel]

You heat treat after grinding, and before finish sharpening.

Otherwise, you will ruin the heat treated edge on the grinder.

rc

 

[Valkman]

Many knifemakers HT before grinding, but I tried it and did not like it. Like rc said too easy to ruin the HT while grinding. I'll stick to gring and then HT.

 

[lobo9er]

Thanks thats what I was planning but it never hurts to ask. Makes sense that the heating up from the grinder wouldn't be helpful.

 

[Owen Sparks]

What metal are you using?

 

[cpirtle]

It's almost impossible to make a knife without some grinding after heat treating, how much you do afterwards is up to the individual maker. As a general rule I do 80% of my grinding pre-heat treat and finish the rest afterwards.

I know a lot of makers who only grind after heat treating, some of them are very well known.

It's not automatically true that you will ruin the heat treat as long as you keep the temperature low, below the tempering level. This is achieved through a combination of using sharp belts, proper belt speed and frequent dips in water. This is why it's important to have a grinder with variable speed and adequate belt length.

A general knifemaking rule is if the blade is uncomfortable to touch with bare hands you're getting it too hot.

 

[Valkman]

For HT for carbon steels get some soft firebricks. I used 2 of them wired together and then hollowed out with a hole in the side for a MAPP gas torch.

Here's an old pic of my set up:

 

[liontribe]

i guess i do maybe 3/4 of the grind work before HT. then i do all the finish work after HT, but i am always careful to keep it from getting even hot to the touch when doing finish grinding. you have to protect that edge. it is just personal preference. as long as you do it right. some knives i have done all grind work before HT and just bead blasted the scale off afterwards. head straight into handle work and whatnot. making knives is a lot like building 1911 style pistols. there is the grunt work, the skilled artisan work and a bit of black magic voodoo that goes into a great knife. that is why steel has fascinated man from the beginning. i think i have been in the heat too long today. i am rambling and waxing philosophy on a friday afternoon. i need a beer.

liontribe

 

[dprice3844444]

valk,i love your polish hillbilly furnace

 

[Valkman]

Yea that's the way it was for about a year until we moved this place and a shop. I ditched the Amazon box in the new shop.

 

[hso]

Grind/forge to about a quarter's thickness on the edge and then heat treat and finish grinding.

 

[Valkman]

Grind/forge to about a quarter's thickness on the edge and then heat treat and finish grinding.

That's how I always did it, but some guys love to do the major grinding after HT. Just profile before HT I guess (and drill all holes), then finish.

 

[Jason_G]

I try to do all that I can before HT, because I don't have a good belt sander. Pretty much every stock removal tool I have at my disposal makes quite a bit of heat, and very quickly, with the exception of my files. With the right tools and a lot of patience and a little know-how, you can do all the grinding you want after HT without annealing the steel, but it takes a "start and stop" technique to let the steel cool off periodically, and sometimes some agua or machining lube to help attenuate the friction. I'd rather remove everything I can before HT, and then just hand grind the final edge.

Jason

 

[hso]

Don,

I never understood why anyone would want to put all that work into grinding something that's hard and waste all the belts and time when they could grind while soft. It really isn't that hard to leave enough meat on the edge so that it doesn't get all weird on you in heat treat and still not be 1/4" thick. Since I was taught to forge I didn't have a choice but to forge to quarter thickness. The couple of times I forged too close to finished I had to use the "flatter" to take the ripple out of the edge.

 

[messerist]

I hand file all of my blades after forging. I forge close to the final shape and use file to clean everything up. After heat treating it is almost impossible to use a file to shape the steel. I use succesive grits of sandpaper to get my final finish......sheeesh! One of these days I'm gonna get a grinder!

 

[lobo9er]

anyone know about any good "how to" heat treat vids on youtube or other sites?

 

[Smokey Joe]

Belt Grinder for Grinderless Knifemakers...

Harbor Fright (oops, Freight!) sells a dandy 1x30 belt grinder for about 50 bucks. Jantz Supply will set you up with all the grits you could ever need on 1x30 belts. Well, mebbe not ALL the grits, but plenty to get you started. Anything Jantz doesn't have, Lee Valley will.

It being that cheap to get a belt grinder, I don't quite see why any knifemaker who wants one doesn't have one.

My cheap Chinese Harbor Freight Special has worked just fine for a couple of years, now. It probably won't last forever, but I didn't pay a forever price for it, either.

Harbor Freight: In your town; consult yellow pages. They also advertise heavily, even in the latest American Rifleman.

Jantz Supply: www.knifemaking.com

Lee Valley: www.leevalley.com

You COULD spend $300-$700 bucks on a 2x72, ending up with a variable-speed Bader, but you don't have to start there!

 

[MadMusial]

Off topic but how does one learn to forge to begin with?

 

[lobo9er]

Off topic but how does one learn to forge to begin with?

for me it started a couple months ago i had a camp fire and put in the fire a piece of metal i cut off some old farm equipment i found buried in the backyard. after it got cherry red i put it on a big rock and smashed with a hammer, and it started to shape to my surprise. after doing that 2 or three times i went to harbour frieght and bought a 55 pound anvil and 2.5 pund hammer from walmart. now i got a couple crude knives and a couple of tomahawks started. To be honest its pretty easy thing to goof around with. a forge is easy to setup with some bricks. I use a shop vac to to blow in to it to get it hot and it works pretty well. its something I wish started doing a long time ago.
The anvil cost me like 65-70 with tax not a huge investment. Also I am looking at picking up a belt sander for between 50-150 so all together when all said and done maybe 200 bucks total for all i want to do.

 

[Valkman]

Right, hso. I never ever has a blade warp on me in HT and then just clean it up, do some small grinding and put the handles on.

 

[lobo9er]

..............

 

[JTW Jr.]

I never understood why anyone would want to put all that work into grinding something that's hard and waste all the belts and time when they could grind while soft.

The reason some do it , is to be able to send batches of blades in for HT. The more you send in a batch , the more economical it is.

I usually rough grind mine , then send for HT. The blaze orange belts make quick work of HT'd steel.

Harbor Fright (oops, Freight!) sells a dandy 1x30 belt grinder for about 50 bucks.

I went thru two of those when I started , they run too fast and the belt life is short.

A 1 x 42 is a better option ( like a Delta ) or the 2 x 42 from Sears is a much better option , with much better tracking.

Though I have a Bader B3 now , the 1 x42's and the 4x36's still get used in the shop for different tasks.

 

[cpirtle]

My general rule of thumb before heat treat is the thickness of a dime, never have had a blade warp on me. I do try to leave them a little thicker but it depends on the blade.

As for grinding after HT, it's personal preference. On smaller blades I like to do more grinding after heat treating in part because it's harder to make a mistake. Setting the blade down crooked on the belt pre-HT will leave a nice dig, post-HT not so much. As JTW said, the Blaze belts rip through anything.

As a side note, I spent the whole day today normalizing/annealing 4 blades that need to be delivered the week after Labor Day. Just as they were reaching quenching temperature the coil blew in my HT oven :banghead:

 

[cpirtle]

anyone know about any good "how to" heat treat vids on youtube or other sites?

There's a lot of good information out there and a lot of bad information, really depends on what you are going for in a finished product. IMO if you plan on selling what you make you should go to the manufacturer of a given product and use their suggested methods for heat treating.

Kevin Cashen has probably written more about heat treating knives than anyone, I'd start by Googling some of his stuff for starters. Most of it's pretty high level but he has a lot out there in laymen's terms as well, you just need to sift through it.

The best thing you can do is start with a simple steel and master it, then move onto some of the more advanced steel. 1080 & 1084 are great starter steels because they can be quenched at just above magnetic and don't require a soak. Most oil quenching steel is best heat treated with a soak time and for best results you need a way to control the temp for 15-20 minutes.

 

[hso]

I don't recommend anyone look to youtube for good instructional videos without a solid reference from a specialty site or by a known expert. That applies to knifemaking.

For knife making information in general look at the ABS or ABANA or other maker forums and what they're talking about. Many knifemakers put up their own videos on their sites and may also reference videos on other sites.

This is a nice little instruction - http://makingcustomknives.com/heat-treating-a-forged-knife-2/
I especially like his use of a "regulator block" instead of just eye-balling it.