After completing the strap buttons and switch tip made from buffalo horn, attention now turns to the rest of the hardware. The Crow will be fitted with variegated nickel finish metal parts, so I was thinking now about the control knobs. Amber speed knobs seemed like a good bet, but the match to the rest of the guitar seemed less than perfect. One consideration was Daka Ware 1930s bakelite knobs. The brown color and retro look was classic Charlie Christian, so they seemed like a good possibility.
I found some in my parts vault and laid them out on a black background and wasn’t impressed. They’d probably be good on a tobacco sunburst guitar.
I’ve always loved the clear plastic lap steel knobs from the 1940s, so I thought that I could make my own based on an original one. The precursor to the “speed” knob, they were slightly taller and not tapered like modern knobs. They were painted gold or sometimes silver underneath, but I just wanted one for a model. A fairly exhaustive search only turned up a few knobs for sale, and those were in really rough shape. I called a few friends in the vintage trade, but no luck. Finally, I found one in almost new condition—amazing for sixty-plus year-old plastic. Needless to say, it didn’t come cheap.
My idea was to make some replicas in clear acrylic and maybe paint them underneath with slver. The lack of color would help mimic The Crow’s reflective finish without detracting from it. The first step was to make some molds from a pourable silicone material. This entails pouring the silicone over the original knob allowing it to cure for twenty-four hours. The result was very good so I made a few more, including a two-piece mold just for backup.
This is what the mold looks like when fully cured. The next step was to mix up some casting acrylic in a cup. The amount of catalyst is determined by the total thickness of the part, and I’d have about ten minutes to get it into the mold.
By pouring the first of the material into the center recess I was avoiding any trapped air which would cause bubbles in the finished part.
After another twenty-four hours, it was time to pull the part from the mold and see how it looked.
Not bad for a first try, but it was obvious that I was going to have to sand and polish the part to get it to look like the original. I went ahead and made about another seven parts in order to experiment. I mixed some color into the liquid on a few just to try it, but it wasn’t a good result.
Once I figured out how to sand and polish the molded knobs (using the trusty drill press again) I also tried painting some of the knobs with chrome, silver and copper paint. In the end, it was the fully clear versions that I liked the best.
Here’s the finished knob, polished up and sitting on my desk. I really like the way it catches the light—like a crow’s feathers. I think they are going to look great on the guitar, and the fact that they are not off-the-shelf parts makes me happy too.
I think I’ve found my “signature” look.
Stuff like this is why I keep visiting this site. Making a mold from silicone and casting your own knobs – so cool.
Nice work. I can’t figure out which I’m more impressed with, you for taking on the task or the finished product. Either way, the whole thing is just awesome.
The clear knob does look good. I’ve made a few knob molds myself, but I’ve always cast them in a urethane plastic, which is normally a white or creme color, but can be died to other colors. I rather like making hardware from materials I have around too, though it’s usually something more like billet aluminum. On the last strat style guitar I built I used old marshall amp knobs and a stainless steel pickguard a friend laser cut for me. I’ll have to try some casting acrylic or epoxy. Very cool.