non-metalic valve guides?

[1 Ton Tommy]

I've got this ca. 1959 Martin Mammoth that's in pretty good shape but for the lacquer. Trouble is the piston valves are noisy, tight, maybe too tight but noisy. 1st valve actually sticks sometimes in warm weather or if I wash it in warm water then I can't get it back in till it cools. These valves appear to have been redone and have the workman's initials enscribed on top. No serial number, just 1,2,3,4 stamped on top.

Somehow I press valves such that they twist making the guides bang in their grooves. There's only about 0.005 clearance between the guide and the slot but they still clatter on a spirited passage. My new Wilson has what appear to be nylon guides and they are silent. Are there made nylon guides that would fit my old horn? They are about 0.125 wide with 0.130 slots as near as I can measure. Do they come in over sizes? Or do you take a bigger one and file it down to fit. I'm assuming they are screw-in to the sides of the pistons.

[arpthark]

What some folks do is get the nylon screw of the proper size, with any type of head, and then just file down the nylon head to fit the guide. Have considered doing this on an old rather clanky but sweet-playing Besson euph, but not yet mustered up the courage (or time).

You can always get the valves lapped in a bit, too. To me, it sounds like those tolerances are just a wee bit too tight. I have encountered this in other tubas that have had valve jobs, too. Almost too perfect!

[gocsick]

That's what I did on the Holton sousaphone... grabbed some 3-48 SAE nylon screws from the Ace hardware and spent some time with the belt sander and needle files to make guides that fit.

[bloke]

McMaster usually has nylon screws of the thread sizes needed with heads that are large enough to cut away most of them and leave a rectangular shape that's the size of a valve guide.

It's frustrating to drive to the hardware store, waste an hour doing so, and them not having anything useful - when I can just order something from McMaster and wait two days.. sometimes just one day.

[1 Ton Tommy]

[snip]
You can always get the valves lapped in a bit, too. To me, it sounds like those tolerances are just a wee bit too tight. I have encountered this in other tubas that have had valve jobs, too. Almost too perfect!

All the valves are tight enough that you can come back the next morning after the horn is cooled, press any valve and hear a "pop" as the pressures equalize. That's more and perfect enough, I'd say.

On first valve the clearance is to close to 0 that I might be hard pressed to find lapping compound that fine. Perhaps some crocus cloth on the piston or is that a no-no? I have some wet or dry sandpaper of 2,000 grit also. If doing that with a strip of paper what lube to use? Water? Penetrating oil? kerosine?

[ghmerrill]

Some years ago Dan Schultz kindly instructed me in how to do the valve replacement on my 1924 Buescher Eb tuba using nylon cheese head screws and cutting them to fit the guide slots. It was quite simple, but did require drilling out the original screw hole and threading the new one. The hardest part was learning how to trim the screw head just right. By the third valve, I had it down pretty well -- but at that point I was done. The solution works really well and gives you totally silent valve guides.

I had to get 100 of the cheese head screws, but it only cost a few bucks. I have about 90 of them left and will probably never use them.

Thanks again Dan!!

[Schlitzz]

Some years ago Dan Schultz kindly instructed me in how to do the valve replacement on my 1924 Buescher Eb tuba using nylon cheese head screws and cutting them to fit the guide slots. It was quite simple, but did require drilling out the original screw hole and threading the new one. The hardest part was learning how to trim the screw head just right. By the third valve, I had it down pretty well -- but at that point I was done. The solution works really well and gives you totally silent valve guides.

I had to get 100 of the cheese head screws, but it only cost a few bucks. I have about 90 of them left and will probably never use them.

Thanks again Dan!!

I used an exacto knife, and did this to a besson 3 valve BBb.

[Schlitzz]

On my euph, some years ago, I tracked down some Delvin valve guides for a Besson New Standard. I had the valves retapped for the guides, and had my tech diamond sand them to fit. Lasted about 11 years now, and I have another 4 sets. I probably won’t use them.

[ghmerrill]

I used an exacto knife, and did this to a besson 3 valve BBb.

One useful trick can be to heat the blade in order to make a faster and cleaner cut.

For some reason, I'm pretty inept with an Xacto knife -- or at least I have to have just the right blade in order to not make a mess. But the heating does help. Most often -- if I can -- I just use a single-edge razor blade. Unfortunately, I can't to that on my bass trombone because there isn't enough space to get it aligned to trim some of the bumpers.

[bloke]

I used an exacto knife, and did this to a besson 3 valve BBb.

One useful trick can be to heat the blade in order to make a faster and cleaner cut.

For some reason, I'm pretty inept with an Xacto knife -- or at least I have to have just the right blade in order to not make a mess. But the heating does help. Most often -- if I can -- I just use a single-edge razor blade. Unfortunately, I can't to that on my bass trombone because there isn't enough space to get it aligned to trim some of the bumpers.

Break it in half and chop straight down with a brand new blade.

[MiBrassFS]

.

[arpthark]

I’m curious what is inscribed on top of the pistons.

"Do Not Eat"

[MiBrassFS]

.