[AlanU]

Hello

I'm overhauling a 1934 Selmer Super Sax alto (with the curious bevel gear octave mechanism).
I think it has never really been touched before, the pads could well be eighty six years old.

The problem that brings me to ask for your help is this.
Most of the hinge rods, ie. the palm keys etc. are absolutely solid.
I've tried penetrating oil over many weeks, shock tactics, heat, everything.

When the rods eventually come out they will be destroyed.

What I would like to know is what threads Selmer were using at that time.
All the rods are 1.9mm or .075 inch diameter.

I know I'll need to buy a die to make these rods, but I'm trusting in all you knowledgeable people to tell me what thread Selmer were using.

Thanks a lot
Alan

 

[clarnibass]

I don't remember (never keeping track on the very few I saw), and someone else might know, but if it's 1.9mm diameter (assuming the thread area) then it's likely M2x0.4mm. Instrument threads are almost always under size and even more if it's that old and worn. That said, some manufacturers, especially back then, used pretty non-standard threads.

 

[saxoclese]

These are the specs for Selmer Mark VI altos: main rod size .110" thread 2.5 - .45, small rod size .0937" thread 2.0 - .40. The thread sizes are metric. Drill rod sold in the US is typically measured in inches.

 

[balticband]

These are the specs for Selmer Mark VI altos: main rod size .110" thread 2.5 - .45, small rod size .0937" thread 2.0 - .40. The thread sizes are metric. Drill rod sold in the US is typically measured in inches.

Good day, Saxoclese
Thanks for posting. Please can you tell me which one I should use for lower stack of keys?
Mine has frozen and as I attempted to unscrew it after spraying with WD40 the split head half broken off. I am planning on having it replaced and don't know where to start.

 

[saxoclese]

Good day, Saxoclese
Thanks for posting. Please can you tell me which one I should use for lower stack of keys?
Mine has frozen and as I attempted to unscrew it after spraying with WD40 the split head half broken off. I am planning on having it replaced and don't know where to start.

The head of the drill rod losing an "ear" on a frozen lower stack presents a formidable challenge even for an experienced tech. I would recommend taking it to a professional repair shop if at all possible. Some of the more experienced techs here might have some suggestions, but without knowing your level of skill it is difficult to know what advice to offer.

 

[balticband]

No expertise at all. I fixed it temporarily with rubber band. I was able to make new "head" for my tenor when this happened with bell keys rod at home. I had proper tools. This will have to wait until I get home. I am stuck in Carribean for two month, cruising between Barbados and Sint Maarten. I think tech will be able to get it out, it rotates but hardly. Maybe with the use of pliyers . The area is also difficult to get to it.

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[saxoclese]

With that much of the rod extending from the post, it is possible to pull it out. A trick I learned from my mentor is to use "end cutting pliers" to grip a stubborn rod to twist and pull it out. It needs to be replaced anyway so the nicks in the steel don't matter. You may need to remove the bell keys to get better access to the lower stack.

 

[Reet McVouty]

No expertise at all. I fixed it temporarily with rubber band. I was able to make new "head" for my tenor when this happened with bell keys rod at home. I had proper tools. This will have to wait until I get home. I am stuck in Carribean for two month, cruising between Barbados and Sint Maarten. I think tech will be able to get it out, it rotates but hardly. Maybe with the use of pliyers . The area is also difficult to get to it.

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Ah, now I remember why I play a modern horn ...

 

[frasermanx]

Alum in a super saturated solution held in place next to the rusty part by aluminium foil will dissolve the rust. Time varies from a few hours to days.Any other method usually ends in a small disaster. The rod may be useable depending upon the amount of rust. See musicmedic info on use of ALUM for this purpose in Articles.

Be patient. Speed kills

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[AlanU]

I thank you all for your thoughts on the matter.
I didn't know about the use of alum.
Surely it would also destroy steel needle springs too?

Still need to find out about the threads.

 

[balticband]

Alum in a super saturated solution held in place next to the rusty part by aluminium foil will dissolve the rust. Time varies from a few hours to days.Any other method usually ends in a small disaster. The rod may be useable depending upon the amount of rust. See musicmedic info on use of ALUM for this purpose in Articles.

Be patient. Speed kills

Sent from my LG-H873 using Tapatalk

Thanks for the tip. Seems a little too radical measure in my case since the rod is moving slowly around it's axis. But it is good to know.

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