As my last post was filled with optimism about the technique of burnishing out scratches, it's only natural that this post is filled with soul-crushing reality. I decided to try the technique on another trumpet the other day, this time on a small scratch under a dent at the very back of the stem. The instrument was in for a cleaning, no dent removal was requested, but I thought "Hell, I'll take the dent out at no charge, then it will give me a chance to practice. If it's not perfect, no big deal, because it will still be better than when I started, and they're not expecting the dent to come out."
Wrong.
I learned something important about burnishing - ALWAYS make sure the area you are burnishing is completely clean, not only on the outside surface, but on the inside, too. Any crud on the inside of the instrument will get stuck between the inner surface and the surface of the mandrel you're burnishing on. That results in tiny little dents coming out from the inside of the instrument that only get worse the more you burnish. I had just cleaned this instrument, so I though I was safe, but failed to look down the bell to make sure everything was clean, and somehow a bunch of corrosion had remained in the back of the stem, right in the area I was burnishing. So not only did I do an incomplete job cleaning the instrument (after all my bluster about ultrasonic cleaning in the brochure), but I made the finish worse trying to fix something that wasn't supposed to be addressed. Further, I ran out of time to make it right on Friday, so I'll be trying to fit it in tomorrow.
The myriad lessons of this day merit a list of their own.
1) Check down the bell after cleaning to make sure you got everything out
2) If you didn't, move on to more serious cleaning practices, in this case a dip in Mineral Shock would be next.
3) If a mandrel is catching in the bell, it's because the bell is dirty on the inside!
4) Don't burnish on a dirty piece of tubing!
5) Don't do work the customer doesn't want, even if you think it will "add value."
6) Especially if that work is burnishing on a dirty piece of tubing! In case you forgot, it's not OK to do that!
7) Respect the techniques that have been handed down to you. For instance, burnishing is great, but only if you're willing to commit the time to do it right and not rush.
Number seven is the most important. Respect what others have taught you and respect your craft. Don't get too big for your britches or assume you're becoming an expert just because something goes well once or twice. It took my predecessors a lot of time and a lot of screw-ups to learn the things they've shared with me. It will take me a long time, too. Today was one of those screw-ups I'll carry with me, as I hope to carry all of my mistakes and preserve them in my memory and in this blog. Making mistakes is part of the process of learning and getting better, so I'm trying not to feel terrible about this one. I think I'll be able to make it right, and the experience will become another building block I draw upon as I continue to advance my skills. That, however, doesn't change the fact that with a little more focus and attention to detail I could have avoided it completely.
Sunday, June 23, 2013
Thursday, June 20, 2013
Lesson Learned - 6/20/13
Yesterday I used La Tromba slide/cork grease for the first time. It's great stuff! Thick without being greasy, it required only a little bit to lubricate a slide, stuck well to the inner tubes, and was easy to clean up.
I also did a little personal refresher on burnishing scratches in silver, after reading a post on facebook advocating the practice as a finishing step in repairing brass instruments. I spent about 20 minutes buffing my hand burnisher to get it smooth, then about 10 minutes burnishing a scratch in a trumpet bell, with very nice results. The scratch (which was small to being with) completely disappeared, and after buffing the area to clean up my fingerprints, it looked great. I need a lot more practice at burnishing to get good at it, but I'm glad to have that technique back in my arsenal. It's amazing how I forget things I learned not that long ago when the skills go unused. Writing about these experiences helps keep them in the forefront of my mind, though.
I also did a little personal refresher on burnishing scratches in silver, after reading a post on facebook advocating the practice as a finishing step in repairing brass instruments. I spent about 20 minutes buffing my hand burnisher to get it smooth, then about 10 minutes burnishing a scratch in a trumpet bell, with very nice results. The scratch (which was small to being with) completely disappeared, and after buffing the area to clean up my fingerprints, it looked great. I need a lot more practice at burnishing to get good at it, but I'm glad to have that technique back in my arsenal. It's amazing how I forget things I learned not that long ago when the skills go unused. Writing about these experiences helps keep them in the forefront of my mind, though.
Saturday, June 8, 2013
Slingerland Tympani Clutch Replacement - 6/7/13
These are pictures from an old Slingerland tympani that came into the shop with the entire clutch assembly missing. The pedal was there, and the clutch shaft was there, but nothing else. Without the clutch, the drum couldn't be tuned, and a tympani that can't be tuned is pretty much just a big expensive tom.
I was able to track down a clutch assembly from Falls Percussion in New Jersey, and with a few additions on my part was able to install it and get the drum back in working order.
In the center left of this photo, you can see the clutch box bolted onto the frame of the pedal. Going through the clutch box is the clutch shaft on which the box slides. Inside the box are two cylindrical pieces of steel with a ring of ball bearings between them. A spring at the top of the box pushes down on the upper cylinder, which causes the bearings to press against the lower cylinder and jam up the shaft in the box. This is what allows the clutch to hold its position and keep the drum at pitch. When the pedal is depressed, a connecting rod (visible in the next picture), pulls against a y-shaped release lever (partially obscured by the frame near the center of the picture. It's held in place with the two screws next to the big bolt). This causes the release lever to push up on the lower cylinder in the clutch, pushing the bearings up (which also raises the upper cylinder and compresses the spring), and releasing the pressure on the rod. Then the clutch box can freely move up and down on the rod until the desired pitch is reached, at which point you release the pedal and the clutch locks again.
This is the connecting rod, running from the bottom of the pedal to the clutch release lever. It has a spring on it, but only to take up slack.
I had to make the connecting rod, which was basically just a 10-32 machine screw, tapered a little bit at the head and sheathed in that long spring. I also needed to modify the bolts that hold the box onto the frame. They thread into the frame with 3/16-24 threads, but at the end of each bolt there has to be a much narrower, unthreaded section that fits into a socket on the clutch box. That modification mostly involved filing material away until the bolt fit that socket.
The mechanism is a bit antiquated, but it's also beautifully simple. There are no counter springs - when the pedal is released, the tension of the drum head pulls the pedal up. When the pedal is pressed down, it's pulling directly on the head tension rods to raise the pitch of the head. As the head gets older and loses some of its springiness things becomes a little more sluggish, but as long as it's cared for it seems like a very effective tuning mechanism. Finding parts for it, unfortunately, is a bitch, but I'll always check with Falls Percussion in the future.
I was able to track down a clutch assembly from Falls Percussion in New Jersey, and with a few additions on my part was able to install it and get the drum back in working order.
I had to make the connecting rod, which was basically just a 10-32 machine screw, tapered a little bit at the head and sheathed in that long spring. I also needed to modify the bolts that hold the box onto the frame. They thread into the frame with 3/16-24 threads, but at the end of each bolt there has to be a much narrower, unthreaded section that fits into a socket on the clutch box. That modification mostly involved filing material away until the bolt fit that socket.
The mechanism is a bit antiquated, but it's also beautifully simple. There are no counter springs - when the pedal is released, the tension of the drum head pulls the pedal up. When the pedal is pressed down, it's pulling directly on the head tension rods to raise the pitch of the head. As the head gets older and loses some of its springiness things becomes a little more sluggish, but as long as it's cared for it seems like a very effective tuning mechanism. Finding parts for it, unfortunately, is a bitch, but I'll always check with Falls Percussion in the future.
Lesson Learned - 6/5/13
Sometimes flute knock pins just aren't worth removing.
Selmer flutes, especially model FL300, and some Bundy flutes have the devastating combination of:
1. Low-grade key oil that dries up on the hinge rods, leaving behind a thick, sticky residue that makes the keys sluggish or sometimes causes them to freeze all together
2. Knock pins that are driven in with so much force I can only assume they load thousands of them into a cannon, then fire that cannon at a flute in the hope that one of the pins will embed itself into the appropriate key. These pins then have all of their excess ground off, so that it's impossible to grab them and very difficult to strike them accurately with a knock pin remover. Not that striking them accurately matters much, because they still won't come out due to the whole cannon-pressure thing.
I got myself into a lot of trouble today trying to remove the knock pin on a lower stack on one of these flutes. As of the end of work today, I've managed to remove it, but only after completely ruining the plate it was driven through (the one between the E and D keys) and severely bending the hinge rod by striking it repeatedly and forcefully with a knock pin driver. I decided to take that plate off so I could remove the lower stack keys and clean and reoil the hinge rod, because the keys were pretty sticky. But having gotten myself into this quagmire, I know that it would have been easier to just reoil the rod and carefully work the keys back and forth until they were free. This wouldn't have been a permanent solution, but now I've given myself a great deal more work to do - work that I can't charge for because I've already given an estimate, plus the work is for a friend. It would have been cheaper to oil the rod with the understanding that they keys would probably gum up again, and just agree to address any future stickiness with periodic oilings for free for the life of the instrument.
I know for the future to just not bother if a pin is giving me that much trouble. Now all I have to do is remember that in the heat of the moment the next I'm getting ready to hammer the living piss out of a flute key.
Selmer flutes, especially model FL300, and some Bundy flutes have the devastating combination of:
1. Low-grade key oil that dries up on the hinge rods, leaving behind a thick, sticky residue that makes the keys sluggish or sometimes causes them to freeze all together
2. Knock pins that are driven in with so much force I can only assume they load thousands of them into a cannon, then fire that cannon at a flute in the hope that one of the pins will embed itself into the appropriate key. These pins then have all of their excess ground off, so that it's impossible to grab them and very difficult to strike them accurately with a knock pin remover. Not that striking them accurately matters much, because they still won't come out due to the whole cannon-pressure thing.
I got myself into a lot of trouble today trying to remove the knock pin on a lower stack on one of these flutes. As of the end of work today, I've managed to remove it, but only after completely ruining the plate it was driven through (the one between the E and D keys) and severely bending the hinge rod by striking it repeatedly and forcefully with a knock pin driver. I decided to take that plate off so I could remove the lower stack keys and clean and reoil the hinge rod, because the keys were pretty sticky. But having gotten myself into this quagmire, I know that it would have been easier to just reoil the rod and carefully work the keys back and forth until they were free. This wouldn't have been a permanent solution, but now I've given myself a great deal more work to do - work that I can't charge for because I've already given an estimate, plus the work is for a friend. It would have been cheaper to oil the rod with the understanding that they keys would probably gum up again, and just agree to address any future stickiness with periodic oilings for free for the life of the instrument.
I know for the future to just not bother if a pin is giving me that much trouble. Now all I have to do is remember that in the heat of the moment the next I'm getting ready to hammer the living piss out of a flute key.
Wednesday, June 5, 2013
Lesson Learned - 6/4/13
I'm starting to get a better understanding of how pads age and how the behave as they get older. A skin pad - like a clarinet pad - that seals firmly around the entire diameter of a tone hole would be expected to seal. But if it's an old pad, it can leak even though there are no obvious leaks around the perimeter. In the past I've discovered this to be the case with pads that have tiny holes in the skin or cracks in the skin. Sometimes on flute pads it's a small cut that I caused with a wayward screwdriver while removing a pad washer. Other times there a sort of bump in the pad where it looks like a small hair was somehow glued into the fiber of the skin. This causes the pad not to lay flat against the tone hole edge. I don't think it's actually a hair, but I don't know what it is.
It also seems that as the skin ages it could lose some of its airtight properties through other means. What these are I can't say, as I must admit that I don't know very much about the materials used in pad skins, but it's conceivable that these materials lose their desirable airtight properties as they age and dry out. I know pad skin is usually made from the organ linings of cows, so presumably the skin ages and decays like any other organic matter. All I can say with certainty right now is that it's frustrating to replace pads on an instrument, then find a leak that's coming from an older pad that showed no outward signs of fatigue.
I also learned that you measure chuck keys by the capacity of the chuck and the size of the pilot holes on the outside of it. So a chuck with a 1/4" capacity and 5/32" diameter pilot hole takes a 1/4-5/32 chuck key.
It also seems that as the skin ages it could lose some of its airtight properties through other means. What these are I can't say, as I must admit that I don't know very much about the materials used in pad skins, but it's conceivable that these materials lose their desirable airtight properties as they age and dry out. I know pad skin is usually made from the organ linings of cows, so presumably the skin ages and decays like any other organic matter. All I can say with certainty right now is that it's frustrating to replace pads on an instrument, then find a leak that's coming from an older pad that showed no outward signs of fatigue.
I also learned that you measure chuck keys by the capacity of the chuck and the size of the pilot holes on the outside of it. So a chuck with a 1/4" capacity and 5/32" diameter pilot hole takes a 1/4-5/32 chuck key.
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