Thursday, January 3, 2013

Mouthpipe-ectomy and Reconstructive Surgery

Mouthpipe project! We all had to remove, disassemble and replace the mouthpipe  on a trumpet as part of our grade in the brass lab. The replacement mouthpipe was cut to length from the yellow brass Allied universal mouthpipe. Like I posted earlier, I had to replace the mouthpipe on what was also my project trumpet, and ended up turning the whole thing in for both grades. I took tons of pictures, basically step-by-step, so without further ado...

Preparing to remove the mouthpipe assembly. There are a number of ways you can unsolder it,  I chose to remove the mouthpipe assembly, then the braces.

I slipped business cards (background) between the solder joints where the front and rear mouthpipe-to -bell braces contacted the mouthpipe assembly, then lifted the it off while heating the final solder joint at the casing-to mouthpipe brace.  I used a drumstick to hold it and not burn my hand on the still-toasty parts.

Then I heated the s-braces and gently knocked them into a water bucket to remove them. Last to go was the casing-to-mouthpipe brace which I lifted off with a pair of pliers while heating. Once the mouthpipe assembly was removed, it was disassembled into 4 parts: receiver, outer upper main tuning slide tube, finger hook, and mouthpipe.

All the pieces, wiped to tin and ready for cleanup

All of the parts to be re-used were sanded and buffed to remove any burnt lacquer and tinning.

I used a pipe-cutter to shorten the wider end of the new universal mouthpipe. I also had to sand off the smaller end to achieve the appropriate inside diameter for that end of the mouthpipe.

Our guide for length was the original mouthpipe

To fit the receiver to the new mouthpipe, I used brass shims for a nice, snug joint.

The gap between the outer main slide tube and mouthpipe was a bit larger, so I expanded the mouthpipe at the end using a Morse #1 taper. I over-expanded slightly, so scraped the outside of the mouthpipe down to size. Doing so can actually provide a better fit than just expanding. I then used brass shims to fill the rest of the gaps and remove any wobble between the parts.

All ready to solder! It was important to constantly check for alignment when constructing the new mouthpipe assembly. Lookin' good here, huzzah!

Soldered, and wiped to tin! (practice bell for dents in the background)

Everything cleaned up, buffed, and ready to be reattached! 

This part of the project went by fast! It was neat to start putting together a lot of our skills on one project. While I had to wait to use a solder bench or particular tool, I could always go take more dents out of the bell or slides or... well that was mostly what I had to do on this horn. Some of the dents took more time and care, like where the s-braces had pushed into the bell (see above--here it has been restored already) especially near the narrow end of the stem. TOUGH! But like I said, it was awesome to put my new knowledge to use and make this trumpet better. More mouthpipe project to come, including an unforeseen structural issue! Stay tuned.