Thor Valve Issues

[Jeff Keller]

I have some questions for you MW Thor owners. My thor is roughly 1.5 years old and is going through some very bad valve trouble. My first valve has already been lapped once. Now my second valve has started acting up as well as my first valve again. I removed the piston and cleaned it - nothing noticeable ( which I do about every 2 weeks). In the bottom cap there is some black grit. I don't know where it is coming from. I am very religious about brushing after I eat - then waiting a bit before I play. The inside on the slides are so clean that I would eat off of them. I have recently switched oils from hetman's to Blue juice. Has anyone had similar issues with their thors? Bad craftsmanship? Should I take it to the shop for the whole horn to be chem cleaned?

Thanks for any help.

J

[imperialbari]

The slides being clean on the inside speaks for your mouth hygiene. The black stuff in the bottom caps may be at least part of the problem, and its source may be a factor not observed by all players. I don’t know you at all, so I cannot be specific. Yet I have seen that problem with my own instruments and with those of others.

The interiors of cases and gig backs are covered with fabric sometimes loosely woven. Fibers will come loose and may enter the instrument via the leadpipe rubbing against the fabric. The bottom caps may also catch some loose matters during transport. Naked horns sharing car seats with pets may also cause dirt collecting inside the valve casings even if horns and pets are not there at the same points of time.

Housewives are picky about husbands and sons not stealing their cloths intended for drying plates and cutlery. My solution is to have plenty of these cloths in the household. Wrapping costly instruments inside their bags or cases is as worthy a usage of these cloths as is their formal purpose. And they are washed whenever I doubt their being clean.

Klaus

[EdFirth]

I had the same thing with my MW2155. If you look at the valve guides there may be lines in the piston up and down. They are from burrs in the valve casing and lapping doesn't seem to help.My repairman also has a tool that makes the valve casing perfectly round, sometimes there are spots around the ports where there are friction points. So it's fixable but you need the right guy with the right tools This repairman is in Central Florida, he also works with Lee Stofer at conventions. If you want to talk with him shoot me a PM, he doesn't have a computer, and I'll give you his number. My valves have been fine for about six months so I think he nailed it. All the Best, Ed Firth

[imperialbari]

What Pachy and I said isn’t contradicting the other. Only I mostly work with older instruments.

Much advise about cleaning instruments warns against too hot water. I have lived in a condo for decades and now live in a rented rowhouse. In both places the hot water supply is governed by two rules, The law says the temperature shall be high enough to kill legionella germs. And economy say that it is not much hotter than the law demands. The result is just below 60 centigrades. In my experience this doesn’t harm instruments but for some rare forms of lacquer, which may disintegrate. But you cannot hold the instrument at that temperature.

Place the instrument securely in the bathtub or in a place where it will neither slide nor tilt. Lead the hot water through a hose to the leadpipe. Use as high a pressure as manageable. Experiment, as too high pressure will make some slides pop out. Activate the valves. With compensating instruments you may need to lock the shift valve down to clean the knuckles of the compensating loops.

Klaus

[JHardisk]

...After spending less than an hour with a narrow fine-toothed file on all four valve guide slots, I never had another problem with the valves...and I never lapped them...not once. I have never cleaned them...not once...and (after filing the valve guide slots smooth) I've used all sorts of of expensive/cheap/petro/synthetic/not-specifically-intended-for-band-instrument-use/etc. oils on my valves - dumping one oil on top of another. They work perfectly.

Perhaps your valve guide slots have the same problem as did mine...??

I had the same issue with my Baer tuba. My repair person did the exact same thing, and my valves have been problem free since! I also had him replace the nylon valve guides with delrin ones that were shaved to fit the newly filed guide slots.

I'll heartily endorse having this done to any MW tuba...

As a side note... I sure with the attention to detail on an 18K+ instrument was higher! Little things like this should not be a problem coming right out of the factory! **Rant over***

[DavidK]

I vote for valve guide slot clean-up. Then thorough horn clean-out. As cited by our illustrious tubenetters.
This can help almost any piston instrument from any manufacturer. I've done it on all of my horns. Works great.

Guide Slot: Potential microscopic machining burrs that go in two directions.
Burs into the guide slot - will cause the guide to hang or drag and wear on the synthetic guides from MW. (I have the same guides on many of my horns, none of which are MW.)
Burs that protrude into the valve casing - will cause friction on the piston itself. You would see the etching in the side of the piston(s)
Also any deformation of the knuckles entering the valve casings - all manner of happenings can cause this.
Any deformations causing out-of-roundness or knock a casing out of straight alignment from end to end.

You might also need to check your hand and finger position and alignment - might not be pressing the valves perfectly straight down their shafts.

The black stuff in the botttom caps of your pistons? That is from the socks that disappear from the dryer. Everybody knows that!!! And then the Martians put it in the darnedest places!!!
Or it's just palin ol' dust or horn grit from use.

Good luck!!! Happy cleaning (again!)

[Jeff Keller]

John,
I know that you aren't to far from me. Where did you take your horn to have this done?

Jeff

[Dan Schultz]

Well.... you've pretty much run the gamut regarding potential problems with your valves. You mentioned that you've seen 'black grit' in your bottom caps. As one person mentioned... that sounds like buffing compound or spent lapping grit. Question.... do you stand your horn on it's bell? That allows all the crap in the bottom on the casings to run right back onto the pistons.

[USStuba04]

Meinl Weston horns seem to be plagued by this problem in all their piston models (maybe not every single horn off the line)...

i had this problem on a 2145... it went to the shop about ten times (not tuba pros unfortunately) and it still wasn't right... so i called the experts...

it seems that when they do the valve guide slots at the factory they dont always come out perfect... and the guides seems to catch near the bottom of the guide slot... maybe it depends on the technician working the line at the factory...

but i know Lee Stofer told me he has a tool he "made" specifically for this problem on Meinl Weston horns...

i also had different friends run across this same thing on a 45 (f tuba) and a 2155 and a 2165... i have seen it a lot...

the guys at Balt Brass also confirmed this type of thing...

fwiw...

[Jeff Keller]

The only time that the horn is on the bell is while I'm openning the case. I don't have a gig bag so it lays flat in the flight case when it isn't in use. Thanks to all for the insight. May you all live 1000 years!

[Lee Stofer]

When Meinl-Weston (and associated instrument names) tuba pistons are being made, it seems that at some step in the process, probably when the valve casing sleeve is being pressed into place, the tool chatters and leaves a rather rough lining to the keyway, or valve guide channel. Instead of taking precious time and and hand-craftsmanship (that would make the instrument cost more), or reviewing the process and improving the process to where this no longer occurred during manufacture (more time and money, although less expensive in the long run), the delrin valve guides can be shaved down to almost nothing and they will work - for a while.

To their credit, in the rare event that I have to replace the valve guides in a Willson, the guides fit right with no shaving - every time. When I re-fit a King 2341/Conn 5XJ tuba with delrin guides, the new guides almost never need to be shaved down. When I take the time to file-out the channels on a Meinl-Weston, etc., tuba, the valves seem to just cease to be an issue. I will mention that special tools and a lot of meticulous care is required to do this job right, and would not suggest this as a do-it-yourself project.

I also have an array of valve casing mandrels and valve sleeves that I use to isolate and correct problems with piston valves. The valve casing mandrel is machined to the diameter of the piston. When I insert it into the valve casing, if it does not move smoothly, then I know that the valve casing is distorted. The top end of the mandrel has a part where I can tap it with a rawhide mallet, the vibrations re-rounding the valve casing until the tool passes through smoothly. The valve sleeve is also steel, and when the piston is inserted, one can quickly tell if the piston is bent or otherwise distorted. With careful tapping on the outside of the sleeve and manipulating the piston in the sleeve, a piston can be straightened and saved in most cases.

My best suggestion to a tuba owner is to keep the instrument clean and well lubricated. When this does not give you a properly-performing instrument, seek professional assistance. Even really cheap instruments can have great-working valves. I'm doing the majority of my playing this summer on a home-made BBb helicon consisting of a Conn 14K body with an old Conn tuba bell grafted on, and a lengthened main tuning slide. This was no high-budget instrument, just old Conn parts. I did nothing special to the valves, just thoroughly cleaned them, properly aligned them, put Hetman #2 on them, and they rival the valves on most new horns.