Introduction: Refurbish a Pocket Knife
I bought this pocket knife a while ago and in that time the plastic scales started to get sticky and gummy. I was about to throw it out but after thinking about it, aside from the gummy handles the knife was fairly decent. So I decided to try and make new handles for the knife. I had some left over pieces of stainless steel that would do the trick. This project was more about seeing if I could make new scales than to fully restore the knife. It would be my first time trying this but since the knife wasn't particularly expensive I figured I had little to lose. So I got to work.
Link to build video.
I started by dissembling the knife making sure to save all the pieces incase I would need to reuse some of the hardware. It was interesting to see how simple a mechanism the folding knife had, this did help to boost my confidence that I might just be able to pull this off. The last pic shows the gummy grossness that is the old plastic scale.
I had some leftover cutoffs from a previous project that I almost threw away but decided to keep. I found two pieces that were big enough and used the original plastic scales as a template to trace the shape on to the steel. This stainless steel isn't very thick its supposed to be used as a flooring threshold or transition so its quite thin but being stainless steel it is very sturdy.
Next I used my portable bandsaw stand and cut out the rough shape of the handles. I made this bandsaw stand a few months ago and I absolutely love it. Here's a link to that instructable if you are interested in making your own.
One of the scales had the spring holder/spacer molded in to it. I needed to replicate this part in order for the knife to work, so I used a piece of paper and a pencil to trace out the design of the spring holder/spacer.
I cut out the tracing and used that as a template to trace on to a piece of brass. I had this brass from a knife project that never got started. It finally came in handy.
Here again using my portable bandsaw stand I cut out the rough shape of the spring holder/spacer. This spacer was thicker than it needed to be so I hand sanded it down to approximately the correct thickness. I made it the same thickness as the locking lever. This sort of stuff becomes obvious when you mock up the parts and things don't line up.
In order to get a good fit from the spring I hand sanded the groove to the correct depth. This was achieved by trial and error. I would file a little then test the fit and file a little more if needed until the spring could sit in the channel.
With all the rough shaping done I got started on refining the scales. I used a C clamp to clamp them together and then sanded both scales at the same time. This way they would be closer to being exact duplicates of one another.
For the inside curves I used a rat tail file to clean up those areas. I also gave them a quick hand sand on a hard surface to remove some of the scratch marks.
In order to drill holes in the same locations I superglued the two scales together and clamped them while the glue cured. This kind of worked or rather it worked for a little while until the scales got to hot and the glue gave out during the drilling. I probably should have used more glue. Either way it worked long enough to get two holes drilled that I could then reference off of.
I did a quick mock up so that I could get the position of my holes. I marked the location of the pivoting hole for the blade and the locking lever.
With the to two pivoting holes marked I used one of the original plastic scales as my template to mark the other two holes that would be for the brass spring holder/spacer. I just had to make sure that the scale was referencing off of the two pivot holes that I marked out first. At this point my confidence was waning I knew if the holes did not line up I would have to start over.
I took the scales to the drill press and drilled the two 1/8 inch holes for the spring holder/spacer. After I drilled the first hole I stuck a broken drill bit in that hole so that the scales would not shift while drilling the second hole.
Now I could use the two freshly drilled holes as a reference to mark the brass spacer. With my hole locations marked I drilled them out. After I drilled the first hole in the spacer I used a brass pin to temporarily attach the scale to the brass spacer and then drilled my second hole using the steel scale as a template. This way I figured the holes would have a better chance of lining up.
With all the parts drilled I did a quick mock up. I wanted to check the fitment and spacing of the different pieces. I got lucky and all of the pieces lined up and there were no major gaps.
Here are all the parts of the knife. I only had 1/8 inch and 3/16 inch brass rods which was fine for the 1/8 inch holes I drilled but the hole for the locking lever was an oddball size and so was the hole for the blade pivot.
I had to use a file and my drill to turn down the brass rods to the correct diameter. This was just a matter of chucking up the brass rod in the drill and pulling the trigger while I held a file against the rod. This removed the material until it was the right size. Think of it as a mini make shift lathe.
Now it was time to assemble. This took me six tries! Parts kept moving on me and sliding out of place I thought about epoxying the parts together at one point. But instead I made a quick little jig that kept the pins in place which made the whole process a lot easier.
So these pictures do look repetitive, which they sort of are. Let me explain in the first two pics I am hammering the pins, which are too long, in place trying to set them so that they do not slide around or fall out. Once they were set I cut off the excess part of the pins using my portable band saw stand, I tell you I just love that thing. Then with the pins the right size I peened them down with my hammer. One of the steps I forgot to film was when I counter bored the outside of the steel scales. My thought was that with the holes being counter bored it would give the brass a place to mushroom out and hold together better.
Once everything was secured I started the long process of sanding down the pins and then cleaning up the entire knife. Sanding is easily the part of knife making that takes the longest. After cleaning up the pins I hand sanded the entire knife up to 400 grit. There are still some blemishes on the scales that were too deep to remove but I am not a perfectionist so I can live with them.
( I failed to mention earlier that I also sanded off the black paint on the blade, this was also done by hand up to 400 grit.)
Here is the finished piece, which I will happily report was a success. The handles are very thin and this is not a knife I would take out in to the woods to work with all day, the thin handles would make this uncomfortable. With that said its skinny profile makes it very comfortable to slip in to your pocket. Its not bulky at all and the handles are comfortable enough for casual everyday use like cutting open boxes or a length of rope or an apple. I am very happy with the end result and this build has me considering trying to make a folding knife from scratch. Thanks for reading!