Let's build a bowie for TEOTWAWKI

[Lamey]

looking real nice... i banged out a 5160 Bowie today myself,  forgot how nicely it works.

[D.Ellis]

Quick update. Here's a pic of the spine showing the sideways warping I got during the quench.

 To get this out I clamp it to a block of steel during the second tempering cycle. I do not try this for the fist temper as the steel is too brittle and I don't want to risk breaking the blade.
Here it is clamped to the steel block. You can see the coin I use so I can bend it slightly beyond straight. It usually relaxes a bit when you remove the clamp.
 
And here it is in the oven for the second temper cycle. 350*f.......for 2 hours.
 
Darcy

[D.Ellis]

Here'se the results of the clamping. It took two temper cycles to get all the bend out, and I had to use a thicker shim, but it came out nice and straight.
 
Darcy

[Lamey]

Darcy, very clever and low stress way to get the warp out.

[D.Ellis]

Thanks Lamey, but it's an idea I stole from a friend, who stole it from someone else. It works great though so I am not feeling at all remorsefull for my thievery.  :D  
Darcy

[akaboomer]

Nice job getting it back straight. I use the same method to get the post quench warp out, learned it from Lin. My steal block has a graduating radius that allows me to do this without a shim. Good job Darcy.

Chris

[D.Ellis]

Thanks Chris. That's a great idea having a curved block to clamp to.
Darcy  

[Steve Nuckels]

Darcy, I have heard of the technique, glad to have additional confirmation of it's success!

Nice work!

Steve
--------
Potomac Forge
W.F. Moran Jr. Museum & Foundation

[Lin Rhea]

I'm enjoying this WIP. I see good solid knife making techniques. I love it.

A side note on the straightening technique. This is just my thoughts about using the curved plate. Not sure but it sounds good. By curving the plate to compensate for the warp, you are able to get full contact with the heavy, heat holding plate. This tends to create or at least maintain expansion while the cooling of the open side contracts. I believe it works either way, but I cant help but think the full contact makes maximum use of the heat that the heavy plate is able to hold.

[D.Ellis]

Thanks guys. Been pretty busy the last few days so progress is slow. Hope to be able to post more soon. Lots of fun stuff coming up.
Darcy  

[D.Ellis]

So, we may need to postpone the end of the world for a bit  :rolleyes:  . Here's the sad story.......with pics. When I rough ground this blade I noticed some black flecs in the steel.......looked like slag inclusions, but I didn't think it was gonna be a problem. This is the fist time I worked with 5160 from this supplier, so I don't know if the batch of steel was contaminated or ???? I should have done a test blade first but I have never had trouble with 5160 before.
Anyway, I convex ground the blade. There was still lots of scratches and such that needed removed, but the edge was ready to put to the test. So, like I do with all my blades, I decided to give it a good workout. First I cut a 1 inch free hanging rope. This tells me the edge is thin enough to cut with minimal effort.
 
So far so good. It cut the rope like it was not even there, so onto the next test. Edge looks perfect at this point.
Next up, chopping wood, in this case a dry piece of pine complete with bark and a couple big hard knots.
 

 After chopping part way through, I noticed a small chip out of the edge. But this was no ordinary chip, it followed a little black inclusion. It was very small so I figgured I'd finish cutting through the log. After cutting all the way through the blade was still very sharp but I noticed this.

 
At this point I feel like barfing. Notice the small bit of steel opened up just above the ripple in the edge. Almost like a blister or a delamination, but this steel isn't laminated so what's it doing there?
Here are a couple more pics of the inclusions.......when grinding the blade, these would grind out and then a new one would appear somewhere else when I ground a little deeper.
 
 
So I decided to break the blade and see what the inside looked like, as I was thouroughly disgusted at this point. Grain was not the finest but not too bad.
 
So, I am back to the drawing board. I will try another blade from this same bar and see if the little black lines show up again. Also will add another normalizing cycle at a slightly lower temp to get the grain size down a bit more next time. I may forge out another blade at the same time with my last piece of 5160 from my previous batch just to confirm that I didn't make any errors along the way to cause this mess.

     
Oh well, could be worse, it could have been in the hands of someone else. And that's why I test every blade before I finish it.......nobody deserves to end up with a dud.
Onward.
Darcy

[Doug Campbell]

That's a real shame Darcy but it happens occasionally. Good job on the QA and catching it in time. Twice I've had "cracks" show in 5160 for no reason I could explain... Still think it's a great knife steel, just maybe some batches aren't up to the standard of others.    

[amar911]

Dang, that sucks! I have a number of 5160 knives and hawks, and it is a tough, reliable steel. Sorry your batch seems to have a problem.

Allan

[Lin Rhea]

Darcy,
          That's too bad about the steel. I have to commend you on your process though. Your whole sequence is right on track with what I would think you should do for a superior knife blade, right down to testing before blade finishing. 5160 is great steel, thus from what I see, you do have a bad bar. It happens, from time to time, but not very often. I had it happen. It hurts to have that much time invested and something ike this happen.
       
     One batch of 5160 I used had little black lines in it, not often, but just enough that every blade was showing at least one. In my case, it was not a crack but I could not use the steel for a finished blade.

   One bar of 1084 simply separated during forging. Three blades in a row! That bar was "given" to me by a well meaning apprentice to use in a demo. I have since concluded (on my own)that the bar had been wrongly used to stir someone's oil to heat it. Effectively being fully hardened and left to sit, it developed cracks from stress, just waiting on me to try to forge a good blade from it.
   
      I think your bar was somewhere in between the two above scenarios.

      Your testing is the one thing that prevented a bad situation. That's good to see in our community. By the same token, testing will insure a well performing product.

      I heard one well known stock removal maker say forging messes up all of the work the steel mill has done for us and we should just grind the blade from a bar. Well,... what if you get a bar that has the same problems you have had? If it's in the bar when you get it, you cant make a good blade whether you forge or not.

       A smith who uses inconsistant, uncontrolled, and risky methods will likely have more problems in different forms. And he will not likely be able to pinpoint the cause. Your methods are consistant and otherwise are successful, giving cause for the belief it's the steel mill's fault or, at least, someone up the chain.

      The reality is what you have shown us. Sometimes we have to pay for the failures of others. You're doing a great job.

[D.Ellis]

Thanks for the words of encouragement guys.
Darcy  

[Lamey]

5160 was known for this 15+ years ago, it seemed to be much more common then.  Im guessing that its some sort of mill flaw, as it was really prevleant no matter who was forging the steel.  This is one of the reasons early on i started using 1095, and W2.  I like 5160, and still use it, but when I started the problem you had was more prevelant then now.  I thought all the current 5160 out there was cleaner, but maybe theres still some of the older stuff in the system?

Like Lin Ive had some current 1084 that would "split" when forged, had one pice that literally split in 1/2 through the middle... I dont and wont use any more of that steel from that supplier.

Let us know what you find out.

[akaboomer]

I feel your pain Darcy. I had it happen on a bar of 5160 that I had.

I am also familiar with the pain of redoing work you have already done, I am in that spot right now. I have very little time to work on knives and was seeing the current project getting close to complete when a mistake on my part has set me back considerably.  

Lin has told me before and again with this set back there are some knives that fight you every step of the way. This has been a fight on mine. So tomorrow I will knock the guard off and go back a few steps to get the results I expect, just won't accept less.

Glad to see that your testing to the leingth you are. Keep us posted on the findings of the steel you are dealing with.

Chris

[Steve Nuckels]

Darcy, sorry the steel failed!  You are serious about your finished product who could ask for more?

Maybe your "Lil Creep" will show up soon and brighten your day!

Regards,

Steve
---------
Potomac Forge
W.F. Moran Jr. Museum & Foundation

[D.Ellis]

Back in the saddle again guys. I am using my last piece of 5160 from my old batch, so it should work out fine. Will try to chase down the new batch's issues later. In the meanwhile.
   
Forged this one out tonight........decided to use my texturing hammer on the flats a bit and this one ended up an inch longer.........13 was an unlucky number anyway            :D     Also a bit wider towards the tip than the last try.
Haven't touched a grinder with it yet.........just hammer work at this point.
Darcy

[David Yukon]

Good luck on this one!!