Introduction: Decorative Markingknife Filework With Epoxy Fill
I recently started to experiment with adding some basic filework to my knife designs. With one of my most recent projects I wanted to take it a step further and try to fill the filework with a colored epoxy.
I experimented with a few different types of epoxy as well as pigments.
Generally speaking there are slow and fast curing two component epoxies on the market (From what I understand the cure time is determined by the hardener). For my knives I use West System 105 Epoxy with the 206 slow hardener (Affiliate link) so I had this already on hand. In addition I got some 5 minute epoxies as well. One thing I noticed was that the slow curing epoxy was way thinner (lower viscosity) than the fast curing epoxies which had a viscosity like honey. This could however differ from brand to brand.
More on which was easier to work with follows later.
There is a wide variety of pigments and dyes available. I chose to try a gel dye and some homemade pigments as well.
Please check out Peter Brown on YouTube and his series on homemade epoxy pigments
(Affiliate links used, thanks for your support!)
For the file work
Last but not least I would recommend the following products when working with epoxy:
Wolfcraft Clamps (Epoxy will not stick to their jaws)
Silicone Kitchen Utensils (These are also great because once cured you can peel excess epoxy right off. Thus reducing waste)
Step 1: What's Filework?
Filework are decorative elements that can be added to the spine of a knife. These can range from relatively simple shapes to very intricate works of art. In some cases they may add some functionality by adding grip to certain parts of the knife.
As the name implies the tool of choice is most often a file but also rotary tools are widely used.
Step 2: Basic Filework With a Dremel Tool
For this example I used a Titanium Marking Knife so the Dremel tool was called for (I do have some diamond files that would work with Titanium).
First step was to use a permanent marker and color the spine of the blade. With my calipers I was able to scribe a few parallel lines (one in the centre and two that marked a quarter of the blade thickness.
Next I used a scribe to mark regular intervals across the length of the spine.
The more care you take with these markings the easier it will be later on.
To cut into the spine I used a range of diamond tipped Dremel bits to create alternating indentations on the markings.
Step 3: Preparing the Epoxy
I decided to use a slow curing epoxy with the dye to fill the filework during the blade glue up.
Unfortunately the pictures of the actual glue up were lost but I'll try to get the procedure across:
Prepare and clean all blade and scale surfaces (preferably with acetone). Remove all dirt, dust and grease (fingerprints) as they can lead to the glue not adhering in that area.
Mix the epoxy (Westsystem offers pumps that'll give you the correct ratio) and add the dye or pigments according to the manufacturers directions (or whatever you found during your experiments). Mix it all very thoroughly and when you think its enough mix it some more.
Glue up the blade by applying glue lightly on all surfaces and use clamps to squeeze out excess glue. Clean up the bolster are (front to scales toward knife tip) as this will be more difficult after the glue has cured.
Since the epoxy I used was so thin I was only able to fill one spine side at a time. Using masking tape I closed up the area I wanted to fill and then slowly poured the epoxy in. I used a small brush to work the epoxy into small nooks and crannies of the filework. A day later I came back and did the same on the opposite side with a smaller batch of epoxy.
So as you can see both types of epoxy come with pro and cons. Thin epoxy will get into small areas easier but you might have to split it up into multiple steps. Thicker epoxy might not get into small areas and you can end up with voids.
Step 4: Clean Up and Filling Voids
Once the glue as properly cured (I usually leave it for several days) I can take the knife to the grinder and sand the sides flush. I usually try to quickly progress from a coarse grit to a fin grit the closer I get to the spine. Apart from the dust carbon fibre is really interesting to work with and easy to sand.
Once all was flush I was able to check how the fill in worked. Apart from a few small voids all went to plan.
Now instead of using the same epoxy to fill the voids I tried a different method. I mixed a UV hardening epoxy with the pigments and was able to patch the holes instantly.
Another possibility to avoid voids/bubbles is to use a pressure pot or vacuum chamber.
Step 5: Finish
After all that work I only had to sculpt the handles and sharpen the blade.
You might ask whats the point of putting all that work into a simple blade? Well in the end this will not make it work better but I learned a new skill and enjoyed the process. I do hope the person I sent the knife to will also enjoy making what they make every time they pic up this blade.
Please do let me know in the comments what experience or tips you have with filework or epoxy.
Second Prize in the
Epoxy Speed Challenge