This method of making plastic is called the baking soda and superglue trick. I have this old vintage ukulele that I'm repairing, and one of the main problems with it was the lowest string was buzzing annoyingly every time it was strummed. This was because the bridge saddle had chipped right where the string touches the saddle. So using baking soda and liquid superglue I was able to re-patch where the saddle had broken off. In this instructable I hope to explain how the baking soda and superglue method works and apply it by fixing the ukulele saddle.
Step 1: Tools and Supplies
This method can use any number of tools for shaping the newly formed plastic, but the only tools I used were some files of various sizes, an X-acto knife, and a small spoon for the baking soda. The only supplies needed are painters tape, baking soda, and liquid superglue. Note the superglue has to be the liquid kind.
Step 2: Tape Up the Area
Before the plastic can be made the surface has to be prepared to protect the ukulele in case the glue gets spread where it's not supposed to. In order to do this I covered the whole bridge and the surrounding area with painters tape. I completely taped everything except the small portion of saddle that I was going to put the new plastic on. Then after everything was taped I went back with a little more tape and added a sort of dish in the shape of what the new plastic would be shaped as. This set up the next step.
Step 3: Making the Plastic
To make the plastic I used a small spoon to put more baking soda than I needed in the dish I made out of tape. Then, with the liquid superglue, I poured it out onto the baking soda. The liquid superglue soaked into the baking soda, and then I let it sit for one minute before doing anything else.
Step 4: Shaping the Plastic
The last step is shaping the newly formed plastic. To do this I used several different files to shape as much of the bridge saddle as I could before I took all the tape off. Then, when I could file no more, I took all the tape off. The X-acto knife helped get the tape off that wouldn't come off easily. Then with more files I carefully kept shaping the newly for saddle patch until it looked like the same shape as the other side of the bridge saddle. A set of mini files really come in handy when being extra careful not to scrap the wood of the bridge. Once it is filed to the desired shape you are done. There is nothing more that needs to be done for the plastic. Of course in your case, however, you could paint to your desired color, but for me, clear is fine.