Repairing a cracked bone handle on a Canal Street
Posted: Tue Jan 07, 2014 2:44 am
Phil sent me a Canal Street for repairs. The bone was cracked across the width of the handle at the mark side pin and also a tiny crack at the rocker pin on the pile side. The cracks were tight and would not photograph well. It appears to me that someone dropped the knife with the blade open and stepped on it. That is the only way I can think that the knife would be cracked as it was. The missing piece of bone at the rocker pin on the mark side is consistent with that sort of damage.
#1
I tried to take some pictures of the gluing process but the glue is very thin and invisible so there was nothing to see in a photo either. This is the glue I used, Zap-A-Gap Thin. It is a thin cyanoacrylate glue with the viscosity of water and will get into the cracks better than thicker glues. I applied a drop at the pin on the liner where the bone is missing with the knife tilted so the glue would run under the bone and up into the crack. I gave it about a minute to dry, (drying time is listed as 1 to 5 seconds) and applied a second coat. I waited another minute and applied a third coat, which did not run under the bone but stayed where I put it, so I wiped it of with a clean cotton rag. Knew then the other coats had penetrated and dried, sealing the bone to the liner.
Then I applied a thin line of glue across the crack, allowed it to dry and sanded off the excess with the 3M polishing paper shown in pic #2 with the glue.
#2
This is a high-resolution scan showing the crack after gluing, sanding and polishing on a buffer, but before filling the gap in the bone.
#3
Now I decided it was time to repair the missing piece of bone. The missing piece is so small it would be very difficult to cut a piece of bone to fit there, so I filled the hole with homemade filler.
The filler is made of Quik-Cure epoxy. This is a private labeled epoxy I am told is really a golf club epoxy. Most knife makers supply houses have their own version of this. This came from USA Knifemakers Supply, which is also Midwest Knifemakers Supply.
#4
The epoxy is mixed with bone filings. You have to guess at the color, I was going for a match to the reddish color on the mark side of the knife, but the bone is more yellow on the bottom.
#5
I used a small amount of the epoxy and a little more hardener to make up for the bone filings I was adding.
#6
I had to work quickly as the epoxy hardens in 5 minutes and I only had about 2 to 3 minutes that I could work with the mixture, so I mixed the filler applied it and used scotch tape to hold it in place while it hardened.
#7
In this pic the filler is hardened and ready to work. I actually allowed the mixture to cure for 48 hours so that it would be good and hard and the epoxy fully cured.
#8
This is a block of micarta with a piece of thick leather glued to it. Among the various uses for it, it makes a nice sanding block. I have a piece of 600 grit 3M polishing paper in the slot and across the top. I move the knife across the polishing paper to sand/polish it. I worked from 600 grit up to 6000 grit polishing paper.
#9
I find it easier to move the knife across a large piece of paper than to use a tiny piece of polishing paper and move it across the knife.
#10
While gluing the crack I noticed an area of open pores in the bone to the left of the hole where the shield should go, easily seen in the first picture of this topic). At this point I decided I would take a shot at filling them with the Zap-A-Gap thin glue. I laid a thin coat of the Zap on the open pores. Here is the knife with the glue on the open pores.
#11
In this next picture I have the knife supported in a vise so I can sand the handle. The knife blade is clamped between the supporting jig and the leather face of the vise jaw so as to not damage the blade nor exert any side pressure on the knife. It allows me to sand/polish on an assembled knife and hold it securely without any side pressure on the open blade.
#12
This is a pic of the knife holding jig by itself.
#13
After using the 3M polishing paper on the glue where I glued the open pores to smooth it out and remove excess glue I used some No Scratch Pink compound on the buffer and I waxed the knife with Walker Wax.
This is the final result:
#14
#15
#1
Then I applied a thin line of glue across the crack, allowed it to dry and sanded off the excess with the 3M polishing paper shown in pic #2 with the glue.
#2
#3
The filler is made of Quik-Cure epoxy. This is a private labeled epoxy I am told is really a golf club epoxy. Most knife makers supply houses have their own version of this. This came from USA Knifemakers Supply, which is also Midwest Knifemakers Supply.
#4
#5
#6
#7
#8
#9
#10
#11
#12
#13
This is the final result:
#14
Where would I find the Zap A Gap glue? Looks like it would come in handy on smaller jobs like I do.
...thanks for puttin this together,DALE & PHIL