Now that spring seems to be truly here, work on finishing the Sakura guitar ramps up. Here’s a bit of background on the control knobs.
I had decided to use my own handmade control knobs like I did for the Crow. First, I tried a series of metal Tele-style and plastic old-school cupcake knobs—they just weren’t right. The Sakura guitar demands something that both blends in, and complements what’s already there. The chrome just stood out too much and dark knobs did too. So, it was time to pull out the knob-making gear.
The first step is to pour acrylic resin into my silicone mold. I made the form from an original 1947 lap steel knob I got from a collector friend of mine. I was lucky to find one in good shape without any crazing or cracks. The secret to using this resin is getting all the air bubbles out before it sets up. I found that vibrating the material with an electric oscillating sander did the trick.
The surface tension in the mold creates a slight dish shape on the top that I want to remove. I use a fine file and then sandpaper on a stone to take the scratches out.
The fine scratches are then removed on a polishing wheel with some white compound. Spinning the knob slowly in my hand also breaks the edges slightly, which gives the knobs a broken-in feel.
As nice as the clear knobs look, they were slightly distracting on the Sakura’s cherry face, so I had decided to add some opaque silver in the inside cavity. This will tone down the look and match the engraved front plate better.
Here you can see the knob’s full .650" height. Although they are larger than a traditional “speed” knob, their clarity keeps their look balanced on the guitar. I mixed a little yellow into some silver lacquer to match the nickel plating on the front plate.
As you can see, the silver changes the look just enough to subdue the knob slightly. There is still enough clear to allow the background to show through too. After the lacquer cures completely, I’ll swap out the test knobs that are on the guitar.