Final Assembly Matters More Than You Think.
The horn is done. The parts have all been made, assembled, and buffed to a perfect mirror. Believe it or not, this is just the beginning to delivering a fantastic playing experience for an eager client. I've been very careful and patient up to this point and rushing through this final step can completely negate all the other great work that's gone into the horn in a players mind. This is my last chance to check for any errors I might have missed and also make sure the valves are lightning quick and the slides are tight but smooth.
I've already taken some steps to ensure that the horn is washed with purified water and completely dry, inside and out. Since I don't know how long it will be in transit, I need to keep it dry to eliminate the possibility of hard water spots beginning the red rot process. Any water spots I've missed should be purified water and will harmlessly evaporate. I've laid everything out for assembly and also for my final checklist. That huge microfiber towel is critical because at this point, the horn is buffed so brilliantly that a regular towel will leave scratch marks.
Here is a gratuitous picture of the finish quality before I start assembly. Lots of folks will argue that the finish doesn't matter because it will tarnish anyway and, come on, it only matters how the horn plays. That's a load of crap. There is a reason it's called "finishing".
It takes about three days to go through the entire finishing process so I'll collect the parts in this drawer as they are done. I use my upstairs office to keep the finished horn away from the dust and debris that is always in the air in the shop. The drawer is helpful also because the cats generally ignore my asking them to please stay off the desk. Once I sit down to take on final assembly, my first step is to install the leather guard. This gives me an anchor point to be able to handle the horn more easily without leaving fingerprints.
I like to start with installing the stop plates and Amado water key pistons. The screws and retaining clip are so small that it's next to impossible to get in there once the corpus is more heavily populated with other parts.
How well the valves install into the horn is dependent on how well I've done the previous lapping, fitting, and cleaning. There are 46 individual surfaces to check! Each part is carefully cleaned and lubricated once more before being fit together. The top bearing is seated with a special secret valve seating tool (nylon rod with a hole in the middle).
I know that generally, I will not get a second chance to delight my client. One thing that destroys someone's enjoyment of a horn more than anything else is valve hang ups. I have two tests that each valve goes through before I'm confident that the valves will perform lightning fast with no drag.
1. The "click" test- I pull up on each valve and then tap the top of the round screw with my knuckle. The sound it makes tells me how much play there is between the top of the rotor and the top bearing plate. There should be very little, preferably none. I will have done this test already, but a final check will make sure that nothing has changed and the valve will operate quietly and smoothly.
2. The "flick" test- I flick the stop arm with my finger, towards one of the rubber bumpers. The valve should be quick enough to bounce off of both bumpers and return to its original location. If the horn passes this test, I know that any drag that the player might report later is not related to the valve tolerances.
Keys are next. Proper key install and stringing techniques could be a post by itself. Maybe I'll do that later. There are only a few steel parts on the horn and they need special attention both from the maker and the player. Sometimes slow feeling valves can be traced to rust in the hinge rod, key springs, or rivet joints.
Once the valves and keys are installed, it's time to do a few back end checks. I take a compression number off of each valve to make sure it's a perfect seal. The optical scope helps to confirm that the registry marks on the bearing plates are accurate to align the valves. Many manufacturers marks are not trustworthy for precision alignment; Meinlschmidt is usually perfect, but I check anyway.
Since I've built perfectly parallel slides, the slide install is a breeze. With light slide-gel, the fit is tight, but smooth. These slides will last a long time with good compression.
This horn is ready (finally)! It looks and plays fantastically and operates perfectly. I promise that every horn that comes out of my shop will be carefully and patiently finished just like this one. You will be free to focus on your art knowing that I've taken care of your horn. Patient, dedicated, detailed work is the true value of a hand craftsman, accept nothing less!
-Jacob
September 13, 2017