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Background: I am a new tuba player. Played baritone and trombone in middle, high school & college. For the past 25 years or so my only playing is trombone in my church brass ensemble. Just after Easter this year our 82 year old tubist declared that he would no longer play tuba because it is too heavy for him to carry. He would continue playing on a euphonium. I though some about getting a bass trombone and covering the tuba parts but then I bought his tuba and have been taking lessons.

The tuba is a Conn 3J, manufactured in 1979 according to the previous owner. I had it chem cleaned and a few dents un-dented.

My problem is that the 1st valve sometimes works correctly, sometimes it gets sluggish, returning a little slowly. That can make a series of fast notes problematic.

I have tried numerous lubricants, trombone slide-o-mix (worked quite well), mixed up 4 different concoctions including ultra pure lamp oil with various combinations of Marvel Mystery oil, mineral oil, and several other oils that I read about here on the forum.

The problem did not seem to be lubrication related. Sometimes the valve worked fine, sometimes sluggish. I noticed some slimy buildup in some of the valves so I gave it a bath and brushed out the valves and as much tubing as I could reach.

While it was apart I believe I discovered the problem. It seems as if air is being trapped on the top side of the valve, slowing the return to the up position. Normally air is sucked in and pushed out through the hole in the upper and lower valve caps (is this correct?). All of the valves have two felt washers between the valve body and upper cap. It seems as if what is happening is the upper felt sometimes sticks to the cap, blocking outward air flow somewhat, making the return stroke slower.

I also noticed that there is a hole in the top and bottom of the valve body allowing air to flow through. It seems that when the valve is sluggish, the upper felt washer is sticking to the cap, and the lower felt washer is sticking to the valve body, thus blocking both air vents. I trimmed a small flat on the perimeter of the washers so they did not cover the upper valve vent hole when rotated properly. This works until the felts rotate to cover the hole again.

So, what is the fix for this? The felt washers could be glued to the valve body so they do not stick to the cap or rotate and block the vent.

Or put felt washers with a smaller OD so they cannot cover the valve vent hole.

Sorry for such a long description but this seems to be a unique problem. At least I have not experienced it and a bit of searching in the forum did not find it.

Any advice, thoughts, suggestions, wisdom is most appreciated.

Craig T

That is essentially how I cleaned it. I have experimented with the felt washers.

If the upper washer is stuck to the cap and the lower washer is covering the valve vent hole, the valve is sluggish on the up stroke.

If the vent hole is not covered by the lower washer, the valve works correctly.

If the lower washer is covering the vent hole and the upper washer is not sticking to the cap, the valve works correctly.

I have repeated this several times and the results are repeatable.

Currently I am considering cutting all the felt washer to a smaller OD so they can not cover the vent hole. My only concern is if the area of the washers will be reduced enough so that the force of the spring will compress the felt more, causing the valves to be out of alignment.

Thanks for the input.

Would there be any concerns with cutting the felt washers to a smaller outside diameter so they do not cover the valve vent hole?

Is there a reason to have two washers instead of one? Just combining available thicknesses to achieve total thickness needed to align the valve? Some other reason?

I will try to procure some felt washers locally. To get me through today's playing at church I cut the OD of the washers so they do not cover the vent in the piston. So far working fine.

I did not say I had "sludge" in the valves, I referred to it as "slimy buildup". Likely for all the mixing of lubricants. Possibly the trombone Slide-O-Mix, it is whitish colored.

After cleaning I am now using only lamp oil & mineral oil (10:1). Will see how that works.

Thanks for the input. Most appreciated.

Sludge...slime...

I was a little surprised at how quickly it accumulated. It seems that without stopping it the valves would soon be affected.

I am hoping the lamp oil / mineral oil mixture I am using works well.