Bumper material (again) -- and where to get it

[ghmerrill]

I have finally traced an increase in "valve noise" on my tuba to one of the bumpers on the second valve (this is the Cerveny 781, rotary valves). The original bumpers appear to be a (fairly hard) black neoprene that I have rather liked. But where to get it?

Before someone suggests O-rings, consider that these have become harder to get since hardware stores are disappearing and places like Lowes and Home Depot have really reduced whatever hardware they used to sell.

I can go with cork if I have to, but then I'd like to know where I can get the "cork rods" beloved of instrument repair people -- and maybe not have to buy a huge quantity and pay $10+ in shipping? I'd prefer neoprene, at least on one side of the valve. But I'm pretty open. When I replaced the bumpers on my euph, I made them out of plastic cabinet bumpers I got at Lowes. But it was a serious pain.

Also, what size (assuming I can get something like a neoprene or cork rod)? The keepers for these seem to be about 3/16" (or metric moral equivalent) in diameter.

Any insight will be appreciated.

[SplatterTone]

Belt for a Sanitaire vacuum cleaner. Any janitor supply should have it. Get out your razor blade and do a little trimming.

Another material that is a bit harder are the refills for the old Pentel pop-up erasers.

[ghmerrill]

I am reluctant to use rubber (which I presume the eraser would be). Is that vacuum belt rubber, or some synthetic?

[ghmerrill]

I think how to do it isn't so much of a problem at this point since I got a lot of practice in cutting out the bumpers for the euph, inserting them so they'd actually stay in place, and trimming them. Actually having reasonable material in a reasonable size/shape to start with will be a major advance.

Of course, I wouldn't mind having something like a little fiber optic bore scope to see how the valves really look ... And those have multiple uses as well.

[SplatterTone]

I am reluctant to use rubber (which I presume the eraser would be). Is that vacuum belt rubber, or some synthetic?

Vacuum cleaner belt is probably neoprene. I don't know the composition of the eraser, but definitely not rubber.

[SplatterTone]

This is the eraser refill.
http://tinyurl.com/5uladz8
It does not tolerate brute force squashing into place, but when it is there, it lasts a long time. It's harder and, consequently, is not as quiet and the neoprene.

[Pozzie]

Universal Rotor Stop Material at Hickeys
http://www.hickeys.com/cgi/display.cgi? ... /tu984.htm" target="_blank" target="_blank

[toobagrowl]

Funny you mention bumper material 'cuz I just received my silicone and neoprene cords earlier today. The old cork bumpers are getting crusty and crumbly on my M-W, so I placed my order yesterday for the cords.

Here is where I got them: http://www.jlsmithco.com/TUBING-CORD" target="_blank" target="_blank
Highly recommended

[Mark Horne]

I had a similar experience with my Cerveny 681 - the third rotor was quite noisy relative to the others. The bumpers were older neoprene, but I couldn't understand why this one was noisy while the others weren't since the bumpers appeared to be the same age.

I decided to undo the linkage rod and took off the stop arm assmebly then spun the rotor around a few times to see if there were any obvious problems. Not finding any, I put everything back together again. The noise disappeared. Perhaps some of the repair guys could explain why that worked. . .

[ghmerrill]

I had a similar experience with my Cerveny 681 - the third rotor was quite noisy relative to the others. The bumpers were older neoprene, but I couldn't understand why this one was noisy while the others weren't since the bumpers appeared to be the same age.

I decided to undo the linkage rod and took off the stop arm assmebly then spun the rotor around a few times to see if there were any obvious problems. Not finding any, I put everything back together again. The noise disappeared. Perhaps some of the repair guys could explain why that worked. . .

I performed the same ritual in order to isolate the offending sound. The rotor itself is totally free of sound and operates smoothly. I thought the problem would be in the linkage, but that proved not to be true. I completely disassembled and reassembled it, however. It is unworn and functioning flawlessly.

The problematic noise (remarked on by my wife: "One of those valves is noisy!") seems to be related to the one bumper. However ...

There is another irritating noise that has developed with this valve recently that I can only describe as a "clicking". I thought for sure this would be the linkage, but no. If I remove the link arm completely, this clicking is still there. Not in the linkage (it's gone). Not in the valve (it isn't moving). So what's left?

What's left is the paddle lever. The clicking appears to be coming from the spring on the #2 lever. So far as I can see, the spring (coaxial with the rod) is flexing and somehow rubbing on the rod. It's relatively minor, but I can hear it. I have no idea how to "fix" it short of replacing the spring -- which is probably not worth it. Very likely no one else will hear it. But it's irritating -- if only because the other springs don't do it.

[ghmerrill]

Funny you mention bumper material 'cuz I just received my silicone and neoprene cords earlier today. The old cork bumpers are getting crusty and crumbly on my M-W, so I placed my order yesterday for the cords.

Here is where I got them: http://www.jlsmithco.com/TUBING-CORD" target="_blank" target="_blank" target="_blank
Highly recommended

This is a great response because it (a) shows me where to get the stuff, and (b) how much it costs.

Thanks.

[ghmerrill]

Universal Rotor Stop Material at Hickeys
http://www.hickeys.com/cgi/display.cgi? ... /tu984.htm" target="_blank" target="_blank" target="_blank

Great! Another source with clear descriptions and costs. And some other useful items as well! Searches on Google don't turn up these things. Thanks.

[ghmerrill]

Thanks, Bloke. Very useful information that will save trial and error.

I think what I'll do is to collect several of these different materials (the vacuum cleaner belts, and some different materials from the parts suppliers) and see what I like best. Since nowadays shipping costs are often more of a factor than costs of small parts, I may as well get a good selection and go from there.

I don't know why these places charge so much for shipping, and often ship small items in ways that are excessively costly. As an example, the estimated shipping cost from J. L. Smith for ONE piece of neoprene is $8.00. This is for either "First Class Mail" or "UPS ground". But when I order things like flies (fishing) or small parts for firearms (from Brownells), they just stick them in a small envelope and put some stamps on it -- with shipping costs typically not more thant $1 or $2. I don't get it. Must be a matter of "business process" or "best practice" (where "best" doesn't mean best). Even if you ship USPS priority flat rate (and you can get a lot of bumper material in a small flat rate box!!), the cost isn't near $8.00 -- and USPS gives you the shipping materials! I don't get it. End of rant.

[SplatterTone]

The unconventional list wouldn't be complete without a link to strings for the Ashbory bass. These are silicone rubber. My opinion: Soft and quiet, but don't last like the neoprene. You local guitar shop might have them.
http://tinyurl.com/6cae2r2

[Dean E]

Dave Schaafsma wrote: "Go to http://www.mcmaster.com/" target="_blank and look for Amber Polyurethane Rod 1/4" Diameter, 6" Length part numbers 8784K821 (40A Durometer hardness) or 8784K822 (60A Durometer hardness). Some people like the harder one for the stop and the softer for the return."
viewtopic.php?f=2&t=12604&p=100670&hili ... od#p100670" target="_blank