Old king Duo Gravis with ONE valve

[bastian709]

I've recently found an old king duo gravis with a single valve instead of the usual setup in my marching bands instrument storage. The instrument is not in good shape, and it badly needs a cleaning. The slide action is also terrible but visually the slide looks fine, so i properly needs adjustment.

I've looked around the internet to the best of my ability - but i been unable to find any information about a duo gravis with only one trigger.

I've identified the instrument based on the fact that it says Duo Gravis engraved on the bell, but as far i can find, no other king trombone use the weird "P" tuning slide either. So it looks to me like the Gb valve was removed.
The serial number on the bottom of the slide says: 49842

Can anyone share some insight? Was it possible to buy this instrument with only one valve, or was it removed?

Recently i saw that there was an old king trombone (No name specified except for "The Lion King") for sale cheap (around 85 dollars) and I've been toying with the idea of buying the trombone and getting a tech to fit the valve from the old trombone onto the king duo gravis in the original position. Then i would only need the Gb tuning slide and some custom work on levers for the trigger.
Mabye all of this is not worth the money or hassle, maybe i cant even find a tech in Denmark who could do this... but one can dream right?
I'd be interested to hear your all's opinion on this "dream project"

[HawaiiTromboneGuy]

Any chance you have photos of the horn? Sounds cool!

[Burgerbob]

The rare Solo Gravis.

[bastian709]

Had to get my account approves first. He comes some pictures

One of the pictures show an engraving i Danish that says "Hærens ejendom", which roughly means "property of the army". The marching band i play in have always had a good relationship with the Royal Life Guards Music Band, and I've been told that we own multiple instruments that we bought when they upgraded their instruments.

[marccromme]

Cool horn, Bastian. There is plenty of space for an inline Gb valve,

I suggest you bring it to either

Brass Centrum Ullrich Harzer, Sølvgade 9, 1307 København 27 12 63 12

or

Oscar Sundqvist, Gottfried, Kronprinsessegade 44C
1306 København K
https://gottfried.dk/vaerksted-784/

and discuss the possibilites, both are competent repairmen.

Take the bits you might have with you ...

and don't hesitated to pop in at my place in Brønshøj, if you want to try some cool bass bones ...

Best, Marc

[Kingfan]

I am aware of one other horn like this. A member of this chat group from Pittsburg, Pennsylvania has a single valve Duo Gravis (Solo Gravis, as BurgerBob suggests). l live in Cleveland, Ohio where the King horns are and were built and contacted Chuck Ward, a former designer at King, about it. He was not aware of the factory making a single valve bass like this. I lost contact with that chat member and have no idea if he still has the horn. The serial number matches horns built between 1970 and 1975, by the way. Personally, I doubt that a valve from an old King with the lion head logo would have the same .562 inch/14.275 mm bore and in my opinion would not work well with your horn. I am not a professional horn tech, so my opinion is just an opinion. Congratulations on finding such a unique horn!

[bigbandbone]

Can it be pulled to E? If so, I would love to have one!

[bastian709]

Thanks everyone for the great replies. I'll definitely move forward with the project, but its properly gonna be a slow cooking one (And maybe a tad bit expensive?) I'm not too sure about the old king "lion" trombone, but i figure its worth checking out, since the drive is not long.

One of my bandmates told me that working on the duo gravis is unsafe because of the materials used at the time. Sounds like a rumor to me, but I'm feeling a bit naive now... is it actually true?

[Burgerbob]

One of my bandmates told me that working on the duo gravis is unsafe because of the materials used at the time. Sounds like a rumor to me, but I'm feeling a bit naive now... is it actually true?

Perhaps they are referring to the solder, which probably has a higher lead content. Don't eat any!

[BGuttman]

Some of the things to watch out for on old horns from a safety standpoint:

1. The solder used until the advent of RoHS had a higher lead content (usually 30% or so). After RoHS the solder is essentially lead free. I believe RoHS was instituted in the 1990s.

2. Older forms of brass had higher lead content. This high lead brass was for machinability and sometimes is still used for mouthpieces (a reason to make sure that the plating is intact on your mouthpiece).

3. Old instruments that did not get lacquer or silver plate had a "chromate conversion" coating. This coating had to be discontinued because of health hazards because it contained hexavalent chromium (a compound of chromium -- chromium metal like you find on an inner slide is considered safe).

Note that none of these will cause you to drop dead from just holding an instrument. If you are soldering an old instrument, make sure you use fume extraction because there will be lead in the air and breathing in the fumes can cause lead poisoning (takes a couple of years of constant exposure). If you are machining a lead-containing brass you should wear a dust mask since breathing in the dust can cause problems.

Some people's saliva can extract lead from a brass alloy. You shouldn't put your trombone in your mouth, and watch out for holes or defects in mouthpiece plating.

Working on old instruments is not that hazardous. All the things I mentioned for fume and dust control should probably be done even with new instruments.

[brassmedic]

Perhaps they are referring to the solder, which probably has a higher lead content. Don't eat any!

Aw man, there go my dinner plans.

[Doug Elliott]

After 40+ years of constantly working with and handling raw leaded brass, my blood lead level is quite low, well within normal.
I don't do soldering however.