Primitive Archer

Main Discussion Area => At the Forge => Topic started by: osage outlaw on August 01, 2015, 10:38:26 pm

Title: knife grinding question
Post by: osage outlaw on August 01, 2015, 10:38:26 pm
I'm trying to finish up this knife I started a few months ago.  I made a simple grinding jig and got one side looking good.  I can't figure out how to get the other side.  Do I need to bolt a block of wood to the table to get the blade above the wheel gard?

(http://i141.photobucket.com/albums/r55/clintanders/Mobile%20Uploads/20150801_215225.jpg)

(http://i141.photobucket.com/albums/r55/clintanders/Mobile%20Uploads/20150801_215243.jpg)

(http://i141.photobucket.com/albums/r55/clintanders/Mobile%20Uploads/20150801_215254.jpg)
Title: Re: knife grinding question
Post by: JoJoDapyro on August 01, 2015, 10:45:28 pm
We took a dremel to tykes sander to get the edge. We ran into the same issue.
Title: Re: knife grinding question
Post by: Pat B on August 01, 2015, 10:58:10 pm
Clint, what grit belt is that?
Title: Re: knife grinding question
Post by: Loope on August 01, 2015, 10:58:25 pm
Flip your jig over to put the "top" side of the jig down on the table and then grind the knife with blade edge facing down.  Or... grind freehand.  I'm no expert, but have ground all mine by hand with no support... hard to get a flat edge, I wind up with more of a convex edge.

Michael
Title: Re: knife grinding question
Post by: osage outlaw on August 01, 2015, 11:43:57 pm
Pat, I'm not sure what grit it is.  It's the belt that was left on there from when I used it on a bow.  I can check it tomorrow.

Loope, I tried that and the grind was to much toward the edge.  I would screw it up if I tried to do it free hand.
Title: Re: knife grinding question
Post by: JoJoDapyro on August 01, 2015, 11:47:03 pm
Duh on my part. Clamp your knife a bit higher on the wood. I was using a piece of angle and vice grips. I see the issue now.
Title: Re: knife grinding question
Post by: E. Jensen on August 02, 2015, 12:32:16 am
Just learn freehand.  Its not that hard.  You won't regret it.
Title: Re: knife grinding question
Post by: KHalverson on August 02, 2015, 09:51:43 am
Just learn freehand.  Its not that hard.  You won't regret it.


x2
go slow and check often.
Title: Re: knife grinding question
Post by: osage outlaw on August 02, 2015, 10:45:42 am
I'll give free hand a try on the next one. 
Title: Re: knife grinding question
Post by: E. Jensen on August 02, 2015, 10:47:57 am
Also a lot tougher to burn your edge with bare hands.  Still can happen in the blink of an eye, but you have one more sense to detect and prevent.
Title: Re: knife grinding question
Post by: burchett.donald on August 02, 2015, 11:18:44 am
   Clint,
           I do both ways...Jig and free hand on some applications...The jig will give you a true flat grind...With your set up you could use a very square block or object to get yourself above the wheel guard so you can reverse everything...Heavy grit will reduce heat some also...Was the file annealed?
                                                                                                                                           Don
Title: Re: knife grinding question
Post by: osage outlaw on August 02, 2015, 12:00:21 pm
The file was annealed.  I free handed the other side this morning.  It turned out better than I thought it would.  How fine do you get the edge before hardening and tempering the blade?  I'd like to get this one ready for scales today.

E. Jensen, I got just a small discolored spot on the blade from grinding it.  It wasn't burnt, just a slight discoloration.  Will that ruin the edge?
Title: Re: knife grinding question
Post by: E. Jensen on August 02, 2015, 12:12:30 pm
Anything more than straw color is ruined, if its after heat treatment.  Before it is negligable
Title: Re: knife grinding question
Post by: burchett.donald on August 02, 2015, 01:09:41 pm
  Clint like Jenson said, you don't want to get it hot after heat treatment or tempering...It's a matter of preference for some but I will take it almost finished before heat treating...That way all I have is some light work to remove. The knife in the pic is just out of 1900 degree kiln, heat treated and very close to finished as far as stock removal goes...The edge is almost ready for a stone at this point...Like I said matter of preference...
                                                                                                                                               Don
Title: Re: knife grinding question
Post by: osage outlaw on August 02, 2015, 01:34:34 pm
Thanks for the help guys.  I haven't heat treated it yet.  I've been reading about normalizing the metal.  It said to bring it up to a non magnetic temperature and then let it cool off to room temperature 3 times before quenching it in oil.  Does that sound about right?  I have a toaster oven to temper it in.
Title: Re: knife grinding question
Post by: osage outlaw on August 02, 2015, 04:44:24 pm
I screwed this one up big time.  I was on my third round of heating to normalize the blade and I got the tip to hot.  Osage coals can put off a lot of heat.  I'll try to regrind the tip after it cools off.  It was looking so good to. 

(http://i141.photobucket.com/albums/r55/clintanders/Mobile%20Uploads/20150802_161325.jpg)
Title: Re: knife grinding question
Post by: KHalverson on August 02, 2015, 05:04:01 pm
I only grind to about the thickness of a dime before heat treat.
I then hand sand the blade long ways  with 120 grit to get rid of stress risers that can cause cracks during quench.
as far as normalization goes .
I heat to 1 color past non magnetic when the blade has cooled to a black heat I go back into the forge and heat it back up to just non magnetic.
and the third time  I go to just before non magnetic.
after that you can heat back to non magnetic and edge quench that file in canola oil  heated to 120 f and then temper out @ 375-400 for 2 hours
Title: Re: knife grinding question
Post by: osage outlaw on August 02, 2015, 08:09:32 pm
KHalverson, I read some of your older posts about heat treating.  I tried following the way you did it.  I didn't have any canola oil so I used vegetable oil.  I heated it up before I quenched the blade.  It didn't flame up like I've seen on videos.  I ran a file across it after it cooled off and it didn't bite so I think I got it somewhat hardened.  I'll do the tempering tomorrow.  Should I do one heat in the oven or two sessions? 


I lost about a 1/2" of length on the blade and had to do some reshaping on the tip.  It's not as good as it was the first time but it should still do the job.

(http://i141.photobucket.com/albums/r55/clintanders/Mobile%20Uploads/20150802_174942.jpg)
Title: Re: knife grinding question
Post by: burchett.donald on August 02, 2015, 08:44:31 pm
  Nice save on that tip/knife Clint...I would recommend 2 temper sequences at 2hrs. each at 450...K.Halverson may give better advise on file knives...I generally work air cooled steel...154cm. Soooo many different recipes for different metals....That looks like the perfect size blade to skin a deer, Seen a lot of guy's cutting their knuckles with big blades... >:D
                                                                                                                                                 Don
Title: Re: knife grinding question
Post by: KHalverson on August 02, 2015, 09:24:37 pm
nice save!
if a sharp file doesn't bite  you got it hard enough.
do 2 heats @ 375-400
Title: Re: knife grinding question
Post by: osage outlaw on August 02, 2015, 10:51:03 pm
Thanks guys.  I appreciate all the help.  I'll do the tempering in the morning so I can try to get the scales on in the afternoon.  I've got two other knives in progress.  They were ebay blanks.  I got scales on both today.  I'm not sure how good the steel is. I tried drilling a hole in the grip on one and didn't get far.  My center punch rounded over on the point and the drill bit didn't do a thing to it.   
Title: Re: knife grinding question
Post by: osage outlaw on August 02, 2015, 11:00:34 pm
What kind of sanding belt works best with knife making?  And what grit?  I need to get some better belts for my next knife.
Title: Re: knife grinding question
Post by: Blaflair2 on August 03, 2015, 12:23:30 pm
Don, that knife is sweet! How big is that blade?
Title: Re: knife grinding question
Post by: Loope on August 03, 2015, 08:08:02 pm
Which belts work best?  Fresh belts!  Not being sarcastic, but I have found that a used belt may feel like it still has grit, but may not cut well.  If the blade seems to be getting hot faster that normal, get a fresh belt.  As for which belts to use, I haven't tried enough different ones to make a recommendation.
Title: Re: knife grinding question
Post by: KHalverson on August 03, 2015, 08:58:56 pm
I found the craftsman belts  work as good as any I have tried from else where.
I use 50 grit or hogging steel and then go to a 120 grit then hand sand.
Title: Re: knife grinding question
Post by: osage outlaw on August 03, 2015, 11:53:11 pm
I'll have to order a couple of belts.  That one was the only good one I had left.  I did the two rounds of tempering in the toaster oven today.  I think it turned out OK.  I'm waiting on some fine grit sandpaper to finish the blade up.  I'm not sure how clean I'll get the blade.  I kind of like the rough looking knives.  I want people to see it was made from an old file.  Hope to have it posted in a week or so. 

(http://i141.photobucket.com/albums/r55/clintanders/Mobile%20Uploads/20150803_222233.jpg)
Title: Re: knife grinding question
Post by: osage outlaw on August 04, 2015, 01:05:30 am
I've been looking at wet grinding wheels.  Would they be better than a belt sander for knife grinding?
Title: Re: knife grinding question
Post by: Stringman on August 04, 2015, 08:15:34 am
That's looking really good Clint!
Title: Re: knife grinding question
Post by: BOWMAN53 on August 04, 2015, 12:16:58 pm
Looking good Clint.

Stick with a the belt grinder. Granted a 4x36 is a pain to working sometimes.
Title: Re: knife grinding question
Post by: osage outlaw on August 04, 2015, 12:41:13 pm
I've got a 1x30 sander also.  I'm going to order some ceramic belts for that and try it next time. 
Title: Re: knife grinding question
Post by: BOWMAN53 on August 04, 2015, 01:37:17 pm
1x30"are perfect for doing plunge lines.
Title: Re: knife grinding question
Post by: Danzn Bar on August 04, 2015, 05:50:41 pm
Good job clint!!