1850's era Hunting Dagger...Broken Tang Welded

[tippit]

Been awhile since I've posted any knives...busy hog hunting with my longbow on my south central Georgia lease and riding my horses.  Anyway had a fellow wanting a 1850's style hunting dagger.  I've never forged a dagger but thought it would be a good exercise...started today so it will be awhile before finished. 

First rough forge with hammers on a thick old file...



Profiled and bevel grind started...



Plan to do either a twisted metal guard or a pour pewter bolster with deer or elk antler handle.  Something like this one from The Knife in Homespun America by Madison Grant...tippit

[webradbury]

Looks good. Getting that center spine straight would aggravate the fool out of me!

[Elnathan]

This should be interesting. I'm actually working on my second attempt at a dagger right now (1st broke in heat treatment), albeit one from an earlier period.

One critique so far - it looks like you cleaned up the transition between tang and blade to be a 90 degree angle. A radius there would be a lot stronger and avoid making that transition into a stress riser.

[tippit]

Pre-quench grind...I grind to almost finish.  That could turn and bite me as this is my first double edge blade.  Thus more chance for warping.

[webradbury]

Tippit, what kind of sander/grinder do you use?

[tippit]

KMG grinder.  I start with a very aggressive 36 grit 2X72 belt.  Then go to a 220 grit.  I grind my edge down to less than 1/2 thickness of a dime before quenching so I'm almost at final stage when I quench.  I do it all free hand and don't use a rest.

[ddoyle]

The use of the brow tine really sets that knife apart. Hope you find a piece to replicate it. I am not a fan of big knives as a rule unless It is for filleting or cutting bread but that one is handsome. 

[tippit]

I have a small elk antler for the handle and a nice piece of scrap Damascus for the finger guard.  Antler handle will probably be 4-4 1/2 inches.  Probably won't put it all together until I return home to Boston in June.

[tippit]

Good news  Bad news...
I quenched and tempered the blade today.  It had a slight warp coming out of the quench but I was able to straighten that by hand while it was still hot with welding gloves on.  Unfortunately I decided to tap the tang a little to straighten it too, but it got too cold and cracked the tang off.

Bad news is tang is too short.  Good news is the only way to really tell how good your quench is to break the knife to look at the inner structure of the steel.  What you want is the steel to have a fine grain structure looking like gray cream not gray salt.  We got gray cream!  Now the bad news isn't that bad as I can weld the tang or a piece of mild steel back on as the tang is completely hidden inside the elk antler.  After tempering, I finish ground the blade. 

Out of the tempering oven...




Finish grind...

[Elnathan]

Heh. That is exactly how I broke my first attempt at a dagger a four or five months ago, except that mine broke right in the middle of the blade.

How are you going to weld it without messing with the temper?

[Greg Pennell]

Tippit, that blade is looking awesome...I sure look forward to seeing the finished piece.

Greg

[tippit]

Elnathan,
I'll keep the blade in wet sand.  That's the way I soften the spine (blue back) on a  tempered knife with a torch.  If it gets too hot, I'll throw the knife with the welded extra tang back into the forge to re-quench & re-temper...But I'll only straighten with my gloved hands this time

[Elnathan]

Elnathan,
I'll keep the blade in wet sand.  That's the way I soften the spine (blue back) on a  tempered knife with a torch.  If it gets too hot, I'll throw the knife with the welded extra tang back into the forge to re-quench & re-temper...But I'll only straighten with my gloved hands this time

Ah. I actually broke my blade with just my gloved hands, so maybe my experience wasn't as exactly parallel to yours as I thought, now that I reread your other post.

If you are planning on peening the end of the tang or drilling it for pins as per the original, you may find that having to weld a piece of mild steel on the tang to be a blessing in disguise. I don't think I've ever managed to get a piece of high carbon steel completely annealed after forging, despite by best efforts.

[tippit]

Elnathan,
Questions...

What steel were you using, when you broke your blade straightening with gloved hands?  What quench?  I quench in Parks 50 and leave it in for the count of 10.  Then pull it out and have about 30 seconds to straighten by hand or with a hammer.  On this piece, it originated from an Old Nicholson file so I think it harden quicker than if I was using 1084 a very easy steel to work out of the quench.  Plus I spent more time getting the blade straight.  If I had just stopped with the blade and worked the tang after tempering and blue backing it with a torch later, I'd been fine.  Always something to learn especially when things go wrong. 

As to annealing high carbon steel, I know what you are saying.  I've had luck heating between purple and just red.  Then leaving the piece to cool in the hot forge.  This will soften it enough to be able to drill the handle before I quench.  Sometimes it take a couple of cycles and a ruined drill bit though 

Lastly...

If I can't get a good weld on the tang stump, I'll grind the blade back past my stamp to pick up a useable tang and make a shorter dagger.  At least now I think I know how to make a dagger blade as this was my first try after over a dozen years of making knives.  Never really wanted to make a dagger in the past.  Now it may be an obsession!


 

[Elnathan]

I was using 1084 and a brine quench - I forget the exact ratio, but it worked out to exactly one container of salt to in my 2 gallon bucket, so I think 8 oz per gallon.


There is actually a long story behind that particular break. I've used 1084 in the distant  past for a few small projects made out of a 1/8" piece (which always warped terribly, something that put me off 1084 for a long time), and I don't recall any problems getting them to harden in engine oil, but when I went to quench this new piece in my now-standard veggie oil it wouldn't harden. I think I tried something like three times to get it to harden in oil, with no success. By that time any attempt to keep the grain size down had gone out the window.

What I should have done was thermally cycle it and/or re-anneal it and try again with brine some other day, but I was tired, exceedingly frustrated with a wasted afternoon (I had had to wait several weeks to get the chance to run my forge, IIRC), and I figured that the blade was already likely ruined, so I went ahead and tried it with brine, just to see if the steel would at least actually harden. It did harden, quite well, but it also warped badly, so I tried to straighten it and just put way too much pressure on it after it had cooled too much to be pliable. And, yes, the grain was way too coarse anyway.

I'm giving it another shot. Unfortunately, I decided to try stock removal this time round, because I figured that this way I could work at it at home after work in the evenings and save my precious forge time (limited to Saturday afternoons that I can afford to spend at my parents' house) for other projects, plus at least this way the tang will be as soft as possible when I try to peen it (I can't weld, so that was a concern). Given the extreme difficulty of filing tool steel down to shape by hand, I don't think I will be doing stock removal again unless I lose access to my forge (unfortunately a real possibility since my parents are moving and I have no idea where I am going to store my blacksmithing stuff if it can't go with them).

BTW, I have successfully annealed files by throwing them in a woodstove overnight. I've never tried that with a knife in process, though, for fear of decarbonization. Also, it requires the woodstove to be lit, making it a seasonally-specific option.

[WH1]

 


My second attempt at a dagger.  Working 4 faces is a challenge.  The first one I made I broke the a 1 1/2" length of the tip off right after quenching it when I tried to straighten it just a "bit".  What a pain it was to reprofile the whole blade.

[Greg Pennell]

Nice one!  I really like the look of that one...very businesslike.  Good job!

Greg

[webradbury]

I had a bad day at the forge today. First, the hawk I was working on went all wonky and I couldn't get it straightened out. I put it aside and started working on a knife I had forged out a couple of days ago. I was just trying to smooth it out a little bit. After one of the heats,while moving from the fire to the anvil, I dropped the blade with the tongs, right into my water bucket! Took it out and dropped it again and "snap"! Broke mid blade. That was all for the day.

[LRB]

  To get the best anneal for files, and even 1084, you want to spheroidize the steel. That is a process that causes the carbon to form into balls/spheres, and makes hypereutectoid steel as machinable as possible. This happens somewhere in the 1300°+ range, below non-magnetic. If using a forge, heat at a very low redish, below non-magnetic a few times and just air cool. Easier done in a heat treat oven though.

[rich pierce]

Wick, good tip and good to see you back here.

[Elnathan]

Wick, good tip and good to see you back here.

Indeed, on both counts.

[tippit]

Back in business, broken tang TIG welded without any heat going into the dagger blade.  So after my Brook Trout fishing week in Northern Maine and the 4th of July, I should be able to finish it up...tippit

[LRB]

Safest way to correct warp AFTER being  tempered.  C clamp the blade to a thick bar of steel, slip a penny or other reasonably slim sized wedge under the blade over where the warp is at it's apex, tighten down another C clamp to over bend the blade slightly, then do one or more re-tempers until it is straight. Let air cool, or you can quench it in water. On a single edged blade, you can heat the spine at the apex of the warp and a little behind and aft while locked in a vise, being careful to not allow the colors to go into the edge area, over bend some and once over bent, poor water on it. It will lock it straight or straighter. Repeat if necessary. I advise the former method unless you use great care watching the colors, and timing. I have done both methods. The latter method is the quickest, but the former is safer. I most often did the latter. You will not damage the blade in either case using care and common sense. You can re-temper a blade a hundred times at the same temp and do no harm.

[Jay Close]

There's some really useful tips here. I too use vegetable oil for a quench and have occasionally had trouble getting steel quite hard enough. One thing that helps is to heat the oil first, say, 130F. Although it is counter intuitive, the hot oil is less viscous and as a result cools quicker. At least, that's the story I'm sticking to. Cheers!

[LRB]

Very correct, 120° to 130°, except for Parks #50. Parks #50 cools almost as fast as water, but works best between 70° and 100°. Heated Canola oil is the next fastest. Either is very good with the 10XX steels. If you're brave and adventurous, you can try a brine mix warmed to about 110° to 120°. I standard size box of sea salt into 2 gals. water. Some steels such as 01 need a slower cooling oil than 10XX steels.