I was helping my brother clean out his garage when I came across this old beat up trumpet. I did some research online and learned it was made in the 1930’s as a student model. I felt bad to see it so forgotten so I had to breath some new life into it.
You’re going to have to run a power cord through the trumpet and in order to do that you need paracord and a cotton ball.
Gut a section of paracord long enough to run the length of the horn. Tie the cotton ball to the end of a strand of the inner paracord and start to feed it through the trumpet at the end where the mouth piece goes.
Use compressed air to blow the cotton ball through the horn. Once it’s through you’ll have a threaded trumpet.
In the picture you see the valves removed but leave them in when you do this.
Now tie the paracord strand onto the section of paracord you gutted. You should be working at the bell end. Take some all purpose cleaner (any soapy liquid will do) and lubricate the paracord.
Pull the gutted paracord back through the horn until it comes out the other end.