Engine building, applied to sticking trumpet valves

Or cornet actually.

Mine has been plagued with sticking clattery valves. I've done the usual trumpet correct fixes. Some helped, most didn't, and I still had valves that clanked and occassionally dragged.

Then last night, for who knows what reason, my engineering brain kicked in, and I approached the problem from a gear head perspective.

First thing I observed is the brass anti-rotation guides have sharp edges. They aren't rounded over. So they would gouge and catch in the valve slot. Take the rifler files and carefully round them over and smooth them.

Second step, notice that the slot those guides rode in were damaged from the sharp edge of the guides. Dress the slots with the files.

Third step, observe that the way the lock is installed on the anti-rotation guides minimizes support and lets them cock a little. Relocate the locks 180 degrees off, maximizing stability.

4th step. Dress the locks, because when closed they have a sharp edge that can catch on the valve stem. More file work.

5th step. Burnish the valves themselves. Nothing fancy, just a grey scrubby pad. Get all the embedded crud that I can't see out of the valves. Also lets me see high points on the valves, like around some of the brazed in cross tubes. Same with the tubes the valves slide in. Carefully dress those high spots with the files.

So at this point, I'd addressed the friction spots and bind areas. Double check my work. Clean everything up, lube it up, and put it back together.

WOW! The valves are now silent, regardless of how fast I flutter them. They take about half the force to move that they did before. They are no longer sensitive to how I push them, they just work, no matter how sloppy I hold the horn.

Inexplicably, the horn also now sounds better. It was a bit buzzy and breathy before, and isn't now. It sound clearer. Pretty substantially so.

So, I am smuggly tickled to death with myself on this one.

Soooo.....I have....NO idea what your talking about. But congratulations anyway.

~Alex

aFTER I left college and started back into cars again, I always thought that a little "port work" and a "valve job" would make the cheaper horns sound and play so much better.

I kindof learned the opposite way.. i was doing that stuff on horns before i even touched a car.

What, no dry moly?

In reply to foxtrapper:

Just curious, what brand, model and age is your cornet?

But can you fix a rusty trombone?

In reply to 914Driver:

They make valve oil for that purpose.

Interesting.......I've got an old coronet that I've quit playing because of the valves sticking. I had a pro give it a "tune-up" years ago, and it worked for a while, but then they started sticking again. I've tried cleaning and lube, but further work is needed.

thanks for the ideas!

In reply to Joe Gearin:

Just be careful. Those tricks are only needed and will only work on horns that have those problems, so it depends on what type of horn you own. That's why I asked about the make and model. Many times the bores can warp or go out of alignment, just like crank journals in an engine. correcting that problem requires the work of a professional. And speaking of which, you might be surprised at how affordable this type of work is. Sometimes it doesn't make sense to do it yourself. I recently had my Bach Strad worked on by the leading repair guy in my area. He ultrasonically cleaned it, unstuck 3 slides, took out several small dents, effectively align-honed the valve bores, and polished it for $55. Now he told me that I got a great deal, so I wouldn't expect it to be that cheap, but the valves worked better than new when I got it back. And this horn once fell off it's stand and bent the third valve bore, so that's really saying something. Definitely not worth working on myself for that amount of money. Not to take anything away from Foxtrapper. If you've got the time and the desire, go for it, but be aware that it's as easy to ruin the valves as it is to repair them.

I did try the dry moly earlier. As well graphite, and every other auto lube or grease I had. Graphite makes one heck of mess btw.

Cornet is a rather battered old Olds Ambassador. An e-bay special. Don't remember the year, if I ever figured it out in the first place.

And I'll agree with bravenrace, go with caution if you decide to follow my lead. By no means did I glibly attack this horn with a grinder or such. Lots of thinking, and tiny amounts of metal removed with itty-bitty swiss files and such. In some cases, it was just a single light pass, backwards. Like on that tiny burred edge of one of the valves. The only place I actually removed any metal was on the #1 valve, where the anti-rotation ring tab slides in it. It was well chewed up at the top and bottom of the groove. There I had to remove a good mm, maybe 2, of metal to smooth out the slide track.

My coronet is an old King (IIRC) that I've had since I was in elementary school. I'm sure it is worth next to nothing, but it is fun to screw around with.

I'll take a better look and see what my options are. Thanks for the advice guys!

glad it worked out for ya... your olds is prob from the 50's or 60s... good horns...

but I'd be wearry of of doing anything like that on a higher end horn... to many things to mess up and costs to much to have properly repaired if you do mess up... but I think most with a high end horn would take it to a shop anyway lol... entry level horns have much looser tolerances...

that being said... I dropped my rental beginner horn not long after getting it... it landed on it's bell and bounced and landed on the 2nd slide which pinched the valve.. in my infinate 7th grade wisdom after pulling the valve out I figuired out where the bind was and deducted it was from landing on the slide... with my mouthpeice as a lever I managed to get the piston working but would still stick from time to time... not bad for a 7th grade repair job lol...

I had Conn cornet in Jr high and Sr high school. It came with a glass bottle of lube that you put on this an eyedropper. That stuff was the bomb. Only thing I could buy after that came in a plastic squirt bottle and was crap. I evenually put the cornet in the chuch yard sale. The valves were totally stuck.