Stabilizing Cracks - Horn

K

Komitadjie

Joined
May 31, 2011
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1,124
Well, having a slight bit of trouble with my HI, and I thought I'd ask you fellows your thoughts on fixing it. Before I even start, I purchased this one as a "BLEM" with a chipped grip, so I was AWARE it might have grip issues to start with, and I'm not bothered by this at all, just looking for some advice on repair. :)

This is my only HI so far, a 15" villager finish AK (not CAK), with a horn handle. When I purchased it, the handle was damaged around the butt cap from a drop (apparently). I ground the chip away and rounded the bottom half of the oval grip profile a little to blend it out, which fit my grip slightly better anyway. It had a few hairline cracks along the length of the grip to begin with, mostly only visible as fine white lines. Unfortunately, it looks like a couple of them on the top (spine side) of the grip are starting to spread. They are perhaps .020 wide now, and have been visibly growing with use. I've discontinued using the blade for the moment for safety sake until I can get this one patched up. Is simply working some epoxy into the cracks and letting it set suitable for stopping their progression? It's a bit wide for superglue. Or is this a case where I should be looking into re-handling it?

Incidentally, I've been really getting a kick out of it, this is my first Khuk. :) I just had it down at a friend's place this weekend, and we were taking turns playing around chopping through various wind-fallen hardwood branches ~4" thick. It's certainly working well, and the edge is still sharp enough in the sweet spot to grip the back of my thumbnail, even after a couple hours of playing around. A few little rolls and nicks where we accidentally struck outside the sweet spot, but those will come out easily enough. Not worried about it at the moment, because I'm probably going to end up deliberately blunting the blade before I start working on the grip anyway. It was at the end of the session there that I realized the cracks were not stable and were growing.

So, what say you fellows with more experience? Start looking for adhesives, or start looking for a suitable piece of wood and some instruction to re-handle it?
 
I used superglue in my blem. I fill in the crack, let dry and kept repeating the process until it was completely filled. I then used 1500 grit sandpaper in my belt sander to smooth and polish.

I did read that a mixture of jbweld and black graphite powder matches the handle well and should fill your cracks in one application.
 
considering that the cracks are evidently fairly wide (.020 what?? inches? cm?) and growing, I wouldnt use superglue as its fairly brittle, Id use something impact resistant like Gorilla Glue epoxy

if you have the still have the powder from when you sanded out the chip then mix that into the expoxy to match the color, otherwise mixing in powdered charcoal or something else with a similar color to the handle should help make it blend in if you cant find an epoxy already colored to match
 
.020 inches, sorry. I'll get some photos this evening when I can get my decent camera in hand to show more precisely what I mean. There are a pair of them, one each to the left and the right of the spine, at the forward section of the handle. I'm not particularly worried about making an "invisible" repair, this is a working tool, and I'm far more worried about just having it be good and solid.

So the consensus seems to be some adhesive (one vote for epoxy, one for superglue and an accelerator) and some sanding out afterwards, then. Perhaps a highly fluid epoxy? I can think of a few that meet that requirement.
 
Hello Komitadjie,

Before gluing the cracks, you might considering adding some moisture to the handle and see if the horn might swell up a bit. For this you can use lanolin(or any product like hand cream that is mostly lanolin), PURE neetsfoot oil(PURE without any petro additives) or dressing for horse's hooves such as Hooflex(?)(Hooflex and hoof dressings have a tendency to be stinky).Take some time and add multiple coats and see if the horn swells. Even if it doesn't, you won't hurt anything. You can use Superglue after to tighten the cracks up.

Sometimes horn can suffer a little going from Nepal to the drier climate of Reno - in addition to shipping and handling banging around like yours suffered.

Hope all goes well with your AK. These are some great tools.

Peace

Rick
 
I guess the strength worries me more than the appearance, Rick. If those cracks should break open during use at some point, I'm worried that I might lose control of the blade mid-swing as the handle rotates or fractures in my hand.
 
Took a couple photos to give an idea of scale, etc. The crack is .035" wide at the largest point near the steel forward cap, and extends backward visibly to the 'ring' in the center of the AK's handle. There IS visible motion in the crack when stress is applied vertically, torsionally or laterally to the blade.

crack2.png


crack1.png
 
Komitadjie:

That crack looks nasty, and if there is visible motion in the crack when stress is applied, I can see why you're worried about the handle failing during heavy use. And you say that there are other cracks in the handle.

Since you're willing to rehandle the blade if necessary, there's no harm in trying easier things first. I suggest this:

1. Tape the edges around the crack to make cleanup easier.

2. Force as much JB Weld as you can into the crack. Use the long-set version, not the quick-set. It hardens more uniformly.

3. File and sand the surface after it cures.

4. Repeat for any other cracks that are wide enough to force JB Weld into them.

5. Allow plenty of time for maximum cure. I'd wait a couple of days, as I don't fully trust the cure-times printed on labels.

6. Apply some stress to see if there is still movement.

However, those other hairline cracks might also be weak. Therefore, I would wrap the entire handle, provided that doesn't make it too fat for your hand to grip.

I'm not sure what's the best kind of wrapping, where strength is the main issue. Perhaps some other reader can advise.

Good luck and please let us know what you do and how it turns out.

-- Dave
 
If that flexes just right while you're using it, you're in real danger of having a chunk of skin removed from your hand. I'd try the JBweld and see if that works, you can always rehandle later. If you wanted to try wrapping it with fiberglass fabric and using clear epoxy, it might not even change the appearance all that much. And would make a nice textured handle. Best of luck.
 
If the epoxy is inevitable, then is it better to NOT add any Hooflex or mineral oil to try to get the handle to swell first, since the oils might interfere with the bond???
 
I think I'll probably end up working my way upward. I'll start with a low-viscosity epoxy and flow the crack full, perhaps one of the hysol clear or black epoxies. If that fails, I'll consider wrapping the grip. If that is not sucessful, I can always grind the whole mess off with my belt grinder and re-handle it, then!

Happy to hear any more ideas you guys might have, I think I'll be ordering some epoxy here fairly quick. I don't have the right stuff in the shop, but fortunately McMaster has everything.
 
Using a thin, long cure epoxy will be stronger, and is what I am going to do. Then mix in some horn dust for a final filler coat.
Masking everything is a good idea, don't ask how I know...

Dino in Reno
 
good luck, I would be really grateful if you take lots of pictures and post a how to! Ive heard lots of people say that theyve done similar fixes to this one to their handles, but Ive yet to see the process or result
 
My feeling is still to try to moisturize the horn first to see if it will swell and then to address the cracks. If the horn is dried out then treating it will help to maintain the strength of the rest of the horn. Also, if you're topically applying and not submerging the handle, the hoof treatment may be on the edge of the crack but I don't think it would keep you from being able to use epoxy later if it was needed (judicious use of a nail file should clean up the edges). Certainly, if you would prefer to coat it or replace the handle, its your blade so have at it.

Safety certainly comes first so you address this in a way that you feel is going to be safest for you and those around when you're using your khukuri. I'm no expert, I'm just going from memory regarding similar posts. Many others have addressed this problem in the past and in a number of different ways that I've read in the Archives, which is where I would recommend you begin your Search for a wealth of information.

Peace

Rick
 
I would highly recommend using a product called Acraglas by Brownell's shooting supply. It is expensive, but wonderful, tough stuff. Plus, you can tint the epoxy black to match the handle. It comes with a black/brown dye kit.

I recently used it on a rehandled Bura Sirupate and I couldn't be more happy with the results. Plus, there is almost zero shrinkage when it sets. Fill the crack with enough excess, let dry and then lightly sand and steel wool. Finish off with Simichrome polish and then neatsfoot oil.

I would NOT put any oil in the crack first to try to moisturize it. The epoxy will not set properly.
 
As a followup! As of about two days ago I started flowing ZapAGap into the crack, based on some recommendations here, and on another forum I frequent. The crack is nearly filled now, it's taken about half the small bottle so far, layer at a time. Another day or so, and I'll pull out the sanding sticks and start working everything to a nice finish again. I thought about masking around it first, but from my experience with CA glues, that would just end with whatever I used for masking being glued to the handle as well.

I'll take some more photos before I start sanding, I've used the opportunity to fill in the gap around the butt cap as well and stop the little bit of shifting it was doing. Next time I'm buying some CA accelerator!
 
One trick to color epoxy is to add powdered tempra paint to get the color you want. It only takes a little bit to get things like black, etc. Do a bit of experimenting first of course.

As mentioned, black graphite is another option.
 
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