My pocket knife of the last seven years needed a new grip. The blue Neoprene inserts in the handle to help with grip had begun to breakdown. When I would reach into my pocket, if my nails brushed against the Neoprene I'd end up with blue stuff under my nails. This didn't happen when my knife was new. In fact it didn't really start until last year. Anyway this told me it was time for new grips. Originally I was going to replace them with wood. But then the Sugru contest came up and this seemed to be the perfect use for it.
I wanted to do something a little different than just plain Sugru though. So I attempted to embed a pattern and fill it with another color of Sugru. There was some slight distortion so the bear ended up looking a little bit like a beast from one of those highly speculative Discovery Channel specials on pre-historic animals. But overall I was happy with the result.
Step 1: Tools and Materials
- 2.5 mm allen wrench
- Utility knife
- Chisel (or other prying implement)
- Cotton swabs
- Old key card
- Something with which to make an impression
- Sugru (black and orange)
- Petroleum jelly
- Rubbing alcohol
- Wax paper
Step 2: Disassembly
In order to make the most efficient use of the Sugru in its 30 minute working window I took my knife apart. Otherwise I would have to work on each side independently, which would waste material. I did this by loosening the 3 hex screws which hold the knife together. Then I seperated the two halves of the knife and removed all the little bits critical to opening and closing the knife. I put all the screws and bits in a plastic container to make sure I didn't lose them. Then I taped the blade to the handle so it didn't flop open while I was working with it.
WIth the knife seperated I turned to removing the Neoprene inserts. I loosened the grip inserts by cutting around the edges with a utility knife. I then attempted to prize the inserts out with a chisel. This didn't meet with success so I cut a grid into the Neoprene and popped the pieces out of the knife handle.
Step 3: Clean and Prep
Once I removed all the Neoprene I needed to remove the residue of the adheasive used to hold it in place. I used rubbing alcohol on cotton swabs to work all the residue out of the grip cavities.
With that done I then used my finger and cotton swabs to put a light coat of petroleum jelly on the knife body around the grip cavities. This was to prevent the Sugru from sticking to places where I didn't want it.
I repeated this process on the necklace I used to make my impression.
Step 4: Add Sugru
Once I had the knife cleaned up it was time to add the first color of Sugru. I laid out a piece of wax paper and then opened a packet of black Sugru. I worked it on the wax paper for about 30 seconds or so to get it malleable. Then I pressed it into each of the grip cavities. I used an old key card covered with a light layer of petroleum jelly to level the Sugru and remove finger prints from the surface. I pressed the petroleum covered bear into the center of the larger grip cavity and then pulled it out as straightly as I could to try avoid distorting the image. I repeated the process for the other side of the knife.
I had some Sugru left so I put it on the faces of a clamp and used the coated key card to level it out. This came in handy later.
Step 5: Add Sugru Part 2
I waited the requisite 24 hours for the Sugru to cure, than I opened a packet of orange Sugru and worked it into the impressions created in the last step.
I had a lot of extra Sugru so I used it to add a grip to my utility knife. I need to get better at estimating usage.
Step 6: Cleaning, Trimming and Assembling
Twnety-four hours later after the orange Sugru had set it was time to finish it up. I used my fingers, forceps and a probe to remove the small bits of Sugru that had adhered lightly to the knife. Most of these I was able to rub off with my finger tip as the petroleum jelly kept them from sticking tightly.
With the small bits cleared away I set about removing the excess material lumped on top to reveal the design. I clamped the knife to my bench to keep it from moving. Then I extended the blade of my utility knife as far as I could. Then I pushed the knife through the mounded Sugru sort of like a miniature planer. I repeated this until the desgin was fully revealed and the Sugru was level with the top of the grip cavity.
Once you've trimmed it reassemble the knife. One of the screws in my knife serves as the main pivot for the blade. If your knife is the same way don't overtighten this screw or you knife won't open. A little experimentation will get the knife tight, but allow it to open without resistance.