A while back I made this box to practice hand-cut dovetails. And then I wanted to make a tenon style knob. I've never made one before, so I figured 'back to the practice box!'
Step 1: Cut to Size the Knob
I wanted a rectangular knob to match the rectangular box. Also, I've been wanting to work with the African hardwood wenge, (pronounced: wen•geh) as I have never used it.
Wenge is similar to oak to work with. It's harder, a little oily and it tears out easily. And it's expensive, about $19 per board foot.
Using power tools to cut with, I recommend using a sacrificial backing to reduce tear out.
Step 2: Shaping
There many ways of shaping wood. I wanted a simple slope, so I used a dovetail bit on the router table. The slope is in the middle of the piece because I will cut the bottom half into a tenon to run all the way through the lid of the box.
As I said, wenge tears out easily, so I clamped a sacrificial 1/4 inch thick piece of poplar to each end of the knob before routing. Just be sure your clamps are plenty clear of the router bit.
After shaping with the router table I cleaned up the edges with a chisel and eventually light sanding to ease the corners.
Step 3: Cutting the Tenon
Use a chisel to lay out the thickness of your tenon so that when you cut the mortise through the lid, with that same chisel, you will have a good fit.
I used a flush-cut/dovetail saw to cut the tenon down to size. Then I went back to the router table with a spiral up cutting strait but to remove most of the waste. After that, I cleaned it up with a chisel.
Step 4: Cut the Mortise Into the Lid
Since this box was complete and sitting on the shelf, it was a little scary cutting a mortise through the lid!
That being said, this is where I screwed up! I don't have a mortising drill press so I cut the mortise with a hammer and chisel. Where I screwed up is; I tried centering and marking the mortise from both sides and cutting half way in from each side, top and bottom. You guessed it, they didn't line up perfectly! So I had a little tear out on the under side while trying to get the knob to fit. Now that I am done I realize I should have just centered and marked the top, clamped the wood to a sacrificial backer and chiseled strait through from the top.
Step 5: Installing the Knob
I wanted to use wedges to really make the knob last, and add that traditional woodworking touch.
I started by drilling two small holes in the tenon, close to the knob side. Then I took my dovetail saw and cut through the tenon up to each hole. Drilling the hole helps to keep the wood from cracking when you drive your wedges in.
Just to note: when doing wedges like this, your wedge always has to run 90° off of the the grain of the MORTISED wood, not the tenon. If you run a wedge parallel then you may split the mortise. So in this case, when I drive the wedges they will flex the two outer pieces of wenge toward the end grain of the poplar lid.
You also need to chisel a very slight bevel on the two sides of the mortise to make room for the wedges to expand the tenon.
I used oak wedges because I wanted a color contras to the wenge, and the wedges need to be strong so you can tap them in with a hammer.
Because I screwed up my mortise I had the torn out piece of wood and small gaps as a result of fixing, I used a clear epoxy to fill the gaps.
Step 6: Finish
After the epoxy is fully set I used a flush cut saw to trim off the waste on the under side of the lid. Then I used a card scraper to smooth the whole surface. Then finish as you like! The knob pictured has no finish but I will oil it.
Thanks for checking it out! This was my first tenon style knob.