Ffg ground into the spine a bit. Now what?

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Omega Leather Works

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Jun 13, 2007
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I have very limited time to actually work on my knife. Unfortunately that meant grinding in bad lighting last night.

Anyway, on a flat ground blade, what do you do if you grind into the spine? Meaning the blade is a bit thinner than the full tang. I could thin the tang, but lack decent equipment. I've tried before and ended up with a non-flat tang that I ended up chasing forever trying to even out.

Feels like it would almost be easier to taper the tang than try and thin it. Is tapering really that hard?

I also considered rounding the spine to try to blend it into the full width tang, I'm just not seeing an easy transition. It's fairly abrupt into the ricosso/bolster area.

Any ideas?
 
Several options, depending on your skill level and/or determination.

Do the other side to match, so it looks like you did it that way on purpose.

Thin the ricasso. This works, but can throw your center line off if you only do one side. Easier to do if the tang is tapered, so you don't have to thin the whole back end of the knife evenly. Tang tapering isn't too difficult. Number one tip: Get a welding magnet from Harbor Freight. Makes it MUCH easier to hold on to the blade and grind it lengthwise against the platen.

Scrap it.
 
I have a couple blades like this too. What I am doing is making both sides match. i think it should perform fine and still be structurally sound so long as the transition is not too abrupt. You end up with a blade that is a bit thinner than the full tang, still can make a great knife.
 
I just had this occur on my third knife and tapered the tang a bit using the belt sander and granite plate with sandpaper taped down. Slow going on the already hardened steel, but it came out well in the end and the lightly tapered tang is a nice touch.
 
I used to do this often when I first started. Only way to fix it is to thin down the whole knife until the spine is even once again.

Don't try to thin it out by grinding lengthwise against the platen. For whatever reason this has never worked for me even with even pressure. Put your work rest on and with the edge facing down, push the knife against the platen starting at the ricasso and then keep going back and forth. Just like grinding a bevel, just instead the whole knife.

I also like to use one hand as a guide to keep the knife flat. I basically just set my hand on the work rest, sandwich the blade between the platen and my hand and pull the knife through with my free hand.
 
Strigamort said:
Is tapering really that hard?
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Nope. Just grind, file or sand away the stuff you don't want - easy peasy. ;) I taper the majority of my tangs, unless the stock is so thin that it doesn't really add anything to the balance or looks.

Be warned though, it'll spoil you. Once you get used to a nicely tapered tang, a "regular" one just won't quite look or feel right again.
 
Great suggestions guys.

For tapering... So scribe the center like the cutting edge, got it. Do you grind all at once, or like you do a bevel? I mean, grind a small obtuse angle to the scribed center, then slowly work the grind across the entire tang to the ricosso, or just try to get it all in one shot? Fortunately my tang is no wider than the belt.

Off to look for videos...
 
I do mine like a bevel. I start out with a thicker angle and grind the butt to my scribed lines, then I work the grind toward the ricasso.
 
Jason Fry said:
I do mine like a bevel. I start out with a thicker angle and grind the butt to my scribed lines, then I work the grind toward the ricasso.
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Same here, just like grinding a full-flat bevel on the blade. :thumbup:

Establish your center, take baby steps on each side alternately, and just work it back to the ricasso. That's easier to control, and gentler on your belts and steel than trying to force the whole thing all at once.

Another tip that I find tremendously helpful... I leave the tang slightly oversize all the way around, and more importantly, square across the butt before tapering. That gives me a nice plane on which to scribe my center/final thickness, helps me keep it straight and parallel, and allows me to remove any "oopses" that may occur. (Like if you grind over the "edge" of the tang a bit and leave a little divot... just like running the plunge/bevel into the spine... trust me, it happens)

When it's all tapered and straight, it just needs a quick clean-up grind to shape the butt and get the final profile. The result? a nice crisp, square edge all the way around the tang, that won't show gaps when the handle is built onto it.
 
I will add that a tapered tang is actually simpler to grind than most FFG blades, because you don't have to deal with working around a belly.

Viewed from the spine, it's just a long, acute isoceles triangle... don't overthink it. ;)
 
All good advice, or you could call it a FOG (full overgrind) with a busted shoulder.
Ken.
 
Really good stuff! :thumbup:

Leaving a bit around the periphery sounds like a great idea. The butt is already contoured (and rather sharply at that), so I'll need to pay close attention.

As for grinding around the belly... that's why I'm starting with wharncliffes. ;)

Every single day I wish I had a 2" belt grinder. :o
 
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