Acra-Glas repairs for bone handles

[OLDE CUTLER]

One of the books on knife repair that I have, "The complete Book of Pocketknife Repair" by Ben Kelley Jr. has a chapter in it on repairing chipped or broken bone pocket knife handles with Acraglas. Acraglas is an epoxy resin product that has the intended use of glass bedding rifle actions into wood rifle stocks to improve accuracy.

I looked through my collection and saw that I had a few bone handled knives that could benefit from a repair such as this and decided to try it. I made the trip to our local Scheels Sports store and found that they had the Acraglas kits on hand. The kit includes resin, hardener, release agent, mixing sticks and cups, black and brown dye, and complete instructions.

I had a Cattaraugus gunstock jack with a small chunk missing, a Cattaraugus cattle knife with a larger defect, and a Shapleigh cattle knife with missing bone. One thing about doing a repair like this is that for bedding rifle actons you mix up a lot more of the product than you do to repair knife handles. I decided to do all 3 at once to minimize the measuring and dying. The working time with Acraglas is 15 minutes, full cure 24 hours. The problem is to mix it as per the manufacturers directions of 4 parts resin to 1 part hardener. The instructions caution against using a scale and determining the 4 to 1 ratio by weight as the resin and hardener do not have the same density. To mix small amounts with an accurate ratio I ended up with the method of taking a mixing stick (Popsicle stick) and drawing a line squarely across 1 inch from either end. Then dip the stick into the resin up to the line, pull out and let the excess drip back into the container, scrape all the resin off the stick on the edge of a coffee can lid. 4 times into the resin, 1 time into the hardener. Seems to have worked OK. The trickiest part is the dying. The included dye is very concentrated and only 1 small drop is needed to make a medium/dark brown mix. I will admit that the color match is not perfect, but it really doesn't need to be. The dyed resin is of a uniform brown color and the bone handles are somewhat mottled with streaks of lighter and darker brown. Anyone looking at the handles closely will be able to tell that it has been repaired and that is OK. You want to make sure that masking tape "dams" are used to contain the Acraglas to the ares desired.

For the first few minutes the Acraglas will flow into all the nooks and crannies including several #60 holes I drilled into the edge of the bone to anchor it. Jigging the hardened Accraglas with a Dremel tool and small ball end cutter will blend things in.
Cattaraugus gunstock before and after:

Cattaraugus cattle knife before and after:

Shapleigh cattle knife before and after:

After I get the Shapleigh back together. I may try a little brown leather dye on the bone to get it a little closer to matching the Acraglas. Otherwise I think it turned out OK for some old EDC bone handle knives. Those of you who have not tried this for repair of bone handles should look into it. Like a lot of things there are small details involved, but the results will be good.

[glennbad]

That's pretty nice work!

[KleenCut61]

Very Cool , Something I m Looking Forward to doing some day also , A Fine Job ! He also states he makes his own springs , When he has to , I Do as Much Matching and measuring , then Set aside the components till my Shops Done ::nod::K.C.

[1967redrider]

Great work!

I wonder if one day you will be able to 3-D print a (bone) handle repair or add steel that has been worn off back to a blade?

[SteelMyHeart85420]

My mind says no, my eyes say yes! Color match on the Shapleigh isn't ideal, but the Catt's ya gotta look a bit closer. Great job on those repairs.

[just bob]

They look very nice! What would happen if you used the Acraglass to repair the damage and then used the Rit dye method that has been demonstrated on here to get a more uniform color? I think it might work?

[OLDE CUTLER]

They look very nice! What would happen if you used the Acraglass to repair the damage and then used the Rit dye method that has been demonstrated on here to get a more uniform color? I think it might work?

I have been using brown leather dye to color bone handles and as I mentioned, when I put the Shapleigh back together I will apply some to try to even things out. The color matching part of this is the toughest part because the Acraglas looks a little different when mixed than it does fully cured. I don't think it needs to be perfect for an EDC knife. I am not out to scam anyone into thinking the knife has not been repaired.
Thanks for all your comments!!

[KleenCut61]

Please Repost the Shapleigh when she's Done OC . Proper Rocker Pin & Handle Repair and Reassembled Far out way's any Heckling over Authenticity K.C.

[OLDE CUTLER]

The finished Shapleigh.

[Bill DeShivs]

Use powdered instant coffee to dye epoxy. You can use as little or as much as you need to match colors.

[OLDE CUTLER]

Use powdered instant coffee to dye epoxy. You can use as little or as much as you need to match colors.

Thanks for the tip, Bill. I find the color matching to be the trickiest part and the powered coffee would allow more precise control.

[Bill DeShivs]

Use a mortar and pestle to grind the instant coffee.

[brucegodlesky]

Accraglass is the best thing since sliced bread......
As far as measuring goes, I use syringes to get an exact amount. Ya can clean them up with acetone and reuse them.
Also. Accraglass also comes ina paste form (green box) Mixes 1-1 ratio.

[OLDE CUTLER]

I had picked up this Case XX 6375 stockman a while back. I have been carrying it as is, but I wanted to do a full repair on it eventually. The red bone handle material was damaged on the back, and as you can see it had a sizeable piece missing from the front.

The blades also needed some reshaping, especially the sheepsfoot. Finally got it done. The red bone handle material was repaired using Acra-Glas. I mixed a drop of red acrylic craft paint with the Acra-Glas as well as a tiny drop of black on the end of a toothpick.

As you can see in the photo, 1/32" holes were drilled into the edge of the broken bone edge for the Acra-Glass to flow into to anchor the repair area as there are no pins to hold it on. Scuff the metal with sandpaper and degrease everything with acetone before applying. After applying the Acra-glas, take a pointed toothpick and poke the material into the drilled holes to get the air bubbles out. Once fully cured, sand to shape, jig to match, and polish.

Toughest part is matching the color to the Case red bone. The Acra-Glas when mixed with color will be a uniform color unlike the mottled color of the bone. Texture and shine is also not an exact match. Good enough for a EDC though, which is now in my pocket.

[jerryd6818]

Even though the color doesn't exactly match, it looks a hair of a lot better than a big gaping hole in the handle where the bone is missing.

[glennbad]

Wow, that came out pretty nice!

[Doc B]

As everyone says...the color matching is the hard part...just tried this one, on an old Western that was broken...

Retention holes and painters tape to keep stuff away from where I don't want it.

This bone had shades of green throughout...I picked up some Mica powers that are made for shading acrylics. I tried marbling the Acraglas, to break up the single tone.
Jigged with a small round diamond bur...it left it just rough enough, that I took a toothpick, broke it in half and burnished some darker shoe polish, in the depths of the jigging.

Not perfect...looks a little better in hand...than blown up in pictures. I think it made it a little better for EDC.

[orvet]

Great looking EDC!
Nice job.

[edge213]

Just ordered some Acraglas from Amazon.
Gonna give it a try.

[OLDE CUTLER]

Looks great Doc. I have done 4 or 5 now and am still working to perfect the technique. It works great for EDC knives that you can buy cheap because they have a chunk missing.

[edge213]

Do you guys use a dremel for jigging?

[OLDE CUTLER]

Do you guys use a dremel for jigging?

I use a Dremel with a small ball end cutter for jigging.

[Doc B]

I used a dremel, with a small round, diamond bur. I have some small discs, too. I was just trying to stay approximately the size of the existing marks.

[fitzroe]

The Acra-Glas in the green box is a lot easier to mix and work with.It's about like butter and the red is liquid.

[SteelMyHeart85420]

Is it odd that I am sitting here wishing I had a knife with a broken bone handle?