Continuing with the landing gear, I decided to build the cross brace wires today. Before I could wrap the wires, the shackles needed to be dyed to the proper 1917 color.
I had experimented with dying hardware with household lye before, but I was not happy with the results. I knew lye was extremely caustic. I put a small amount into a cup of water and soaked a few bolts. It took forever for the bolts to change color and when they did, the color was chalky and uneven. So, I gave up on the idea.
Oh, what you learn when you ask questions.
I remembered seeing the beautiful silver shackles on Paul Dougherty's Jenny during my visit to Pennsylvania. I asked him "How did you do that?"
"I dyed them in lye"
Remembering my earlier troublesome attempts, I asked him for his technique. Here goes:
1.) Use a lot of lye. Fill the jar with 10 to 20 percent lye and the rest water. It will turn a milky color when you stirr it. At this ratio, the hardware will change color in a minute or two.
2.) The solution is not usable forever. I found that after the water becomes clear again, the chemical change slows down considerably. You can't just add more lye, either. I'n not a chemist so don't ask me for a detailed explanation. Paul just says it's so and it works for me.
3.) Don't get any on you. Lye is mean stuff.
4.) Use a glass container. The chemical reaction generates a lot of heat. Watch out when you grab it. The glass will be hot.
5.) Don't smell it. Notice that my container is outside. Did I mention this is nasty stuff?
6.) When you pull the hardware out of the solution, wash it with clean water.
Below are the shackles from the aircraft hardware store next to the ones dyed in the lye. One thing I noticed - The original factory plating has to be intact. Since the lye only changes the color of the plating, any scratches will still be there when you are finished.
You can do this to bolts, too.
Now that the shackles had been dyed, I started making the cables which brace the landing gear. These are thick cables - 3/16 in - which are bigger than the 1/8 in. cables used in the fuselage.
Because the cables are thicker, do you need to wrap them more? Yes. I checked the Brimm and Boges book and the formula is the same. Each wrapped section is seven times the diameter of the wire.
In this instance, the 3/16 in cable needs a wrapped length of 1 5/16 in. There are three wraps per end. Including the tapered end, the total length of the wrapping is about 4 inches.
Also, the gap between the wraps should be equal to the diameter of the wire, but not less than 1/8 in.
Here our son Nicholas shows the day's handywork. Four cable ends wrapped and ready for solder.
Another thing I wanted to do today was get the spruce for the landing gear airfoil measured and ready for shaping. The airfoil consists of 4 one inch boards and a cross grained bottom board.
I made a cardboard template and traced the outline onto the individual boards.
I will rough cut the shape with the table saw. Before that happens, several lightening spaces will have to be routed on the inside as well as two grooves to accept the landing gear tie rods. All these dimentions were traced onto the boards too.
Now I'm ready to create sawdust. Next shop day. Till then