Tech/maintenance A general thread on DIY repair

[mark_addy]

Hi folks. I accidentally posted these musings in @PigSquealer 's blog - sorry about that - and it was suggested that maybe there might be room here for an advice thread on DIY repair. I get it that 'a little knowledge is a dangerous thing', and that plenty of folks make a fair living fixing instruments that people like me break. It may even be that they will make an even fairer living sorting out the mistakes that a 'dabbler' can get themselves into. Nevertheless, with the proviso that (I would like to think) anyone trying out anyone else's well-meant advice takes full responsibility for their own instrument (and fingers, and lungs) and their own more-or-less ham-fisted execution of any such advice - I have always learnt by doing, and am OK with the idea that 'the man who never made a mistake never made anything'. So with all that said, this is what I dumped into that blog:

I'm new here, and have read this thread (blog) with interest. I have other mechanical interests (motorbikes, museum work on vintage steam / gas / diesel engines etc), and I have a reasonably-equipped workshop (little lathe and miller, oxy-propane gear etc) - but I've never got very far working on instruments. Would you (OP) be open to making the odd contribution to a newbie DIY thread? I know a lot of people would shy off that with a 'don't do that, you'll wreck it' feeling, which I understand - but, for instance, how do you get enough heat into a body tube to solder a pillar back on (and using...electrical solder (v.soft), plumber's solder (less soft), lead-free modern stuff (less-soft again) or ...? ) without neighbouring pillars falling off, solder running everywhere, etc etc?

Perhaps that's a big question, but it's my first one. And (because I'm greedy) here's another different one for fun: has anyone used a 2-part epoxy putty like 'Milliput' to repair a chewed-up beak on a mouthpiece? I have messed up front teeth (for reasons other than music 🙂 ) and I don't like the feel of those chewy protector patches - I seem to eat mouthpieces over time.

I don't have a means to take photos at the moment, as both my kids (the smart phone owners) are now away at university. So this will be a bit text-heavy from my end until I work out how to use an old digi camera someone gave me a while back, and find which cheapo usb-to-something-or-other-card-adaptor it requires to upload pictures.

Folks who find willful Luddites frustrating might want to give all this a wide berth.

 

[skeller047]

Check out Matt Stohrer’s videos on sax repair, they are a treasure. Also look at stephen Howard’s web site, and Music Medic too. Lots of ideas there.

Regarding the mouthpiece, I would use J.B. Weld epoxy, it cures harder than most. I would then use a thin mouthpiece patch. I actually favor using a roll of UHMW tape, just cut a piece off and stick it on. It lasts about a year before needing replacement.

For pictures, just use your phone. Assuming that is that you’re not so much of a Luddite that you don’t have a relatively recent cell phone…

 

[mark_addy]

Check out Matt Stohrer’s videos on sax repair, they are a treasure. Also look at stephen Howard’s web site, and Music Medic too. Lots of ideas there.

Regarding the mouthpiece, I would use J.B. Weld epoxy, it cures harder than most. I would then use a thin mouthpiece patch. I actually favor using a roll of UHMW tape, just cut a piece off and stick it on. It lasts about a year before needing replacement.

For pictures, just use your phone. Assuming that is that you’re not so much of a Luddite that you don’t have a relatively recent cell phone…

That's helpful, I'll have a look. What is UHMW? And...yes, I have an old Nokia with no camera 🙂

 

[jonf]

That's helpful, I'll have a look. What is UHMW? And...yes, I have an old Nokia with no camera 🙂

UHMW is Ultra-High Molecular Weight Polyethylene tape. You can get it on Amazon.

I have used 2 part epoxy to fill in for a missing bite plate on mouthpieces. The one I would use is a J B Weld epoxy, but not the standard one. They do one called Water Weld, which is certified to be food safe, so it gives a bit more reassurance about a lack of toxicity.

If you can fettle a motorbike, you should be able to manage a sax, although as a biker myself, one of the things which initially felt difficult was the low engineering quality of the components - leather, cork, soft brass. You soon adjust, and what initially felt like snags turned out to have at least some advantages.

I also have seriously mangled teeth, but thanks to a good dentist it doesn't impact my sax playing at all.

 

[PigSquealer]

I'm new here, and have read this thread (blog) with interest. I have other mechanical interests (motorbikes, museum work on vintage steam / gas / diesel engines etc), and I have a reasonably-equipped workshop (little lathe and miller, oxy-propane gear etc) - but I've never got very far working on instruments. Would you (OP) be open to making the odd contribution to a newbie DIY thread? I know a lot of people would shy off that with a 'don't do that, you'll wreck it' feeling, which I understand - but, for instance, how do you get enough heat into a body tube to solder a pillar back on (and using...electrical solder (v.soft), plumber's solder (less soft), lead-free modern stuff (less-soft again) or ...? ) without neighbouring pillars falling off, solder running everywhere, etc etc?

Shop knowledge is definitely to your benefit. Sax repair is fun but surprisingly a different set of engineer / spanner man skills. Loads of finesse if you’re after premium play quality / museum appearance.

Who is the victim of your needs ? Charles Conn, Gus Buescher, Ernest Couturier, Frank Holton or Henri Selmer ?

Post / pillar remounting. What position?
Clean the body spot well.
Clean the part & tin with a quality soft solder.
I like an acid paste flux. No filled core on any solder.
Flux & mount the part, and hold correct position with clamp, hinge rod, wire, or ?
Sensitive surrounding area(s) I shield with wet paper towel.
Stab the heat on & off on the pillar and just a wee bit on body.
The solder will melt and flow shortly after seeing the flux start to run.

Repair technician Wes Lee on YouTube has some decent soldering videos.

 

[JayeNM]

I think ANY sort of hardening epoxy or cold-weld product HAS to have a thin protective covering on it, as noted above. The products were not really made nor intended to be put in a person's mouth, so....

Food safe marine JB sounds very interesting but even in that instance, this is an area which is actually getting bitten, more than just coming into contact, so I would still suggest the same...

 

[wakyct]

Repair technician Wes Lee on YouTube has some decent soldering videos.

Thanks, agreed!

View: https://youtu.be/axM19M6OEgA

 

[mark_addy]

Plenty to go on there - thanks folks. I've ordered some of that clever tape to put on a mouthpiece repair. Milliput (which I have) is apparently OK for aquaria once cured, so thanks for the heads-up on that.

First hot job is to break off two pillars on my old Conn baritone which I superglued back on to get through a band rehearsal. I think I'll use a small wire mop to clean the sh*te off the bottom of the foot, and the patch on the sax, before tinning as suggested. (I imagine the foot is silver-soldered to the post, or it'll fall into bits when I heat it up to tin it?). My gas gear is way, way too big - I used to have one of those cheapo butane chef's torches before it packed up, perhaps I should acquire another, or borrow a tiny torch from work to put on my big bottles.

This feels like a good opportunity to share my amusing flux anecdote (I know, crazy guy, right 🙂 ). I read than ZnCl was a good flux, and I was trying to solder nipples (steady) back on to motorbike cables. I had some 'spirits of salts' (conc. HCl) which is sold here as drain cleaner and even comes in the post, and some Zn motor wheel balancing weights which are used since the EU control of Lead regs stopped them being Pb. So I dropped a wheel weight in a pot of HCl, it fizzed like hell (as expected) and eventually...a clear liquid resulted with an apparently insoluble white precipitate in it. I scratched my head for weeks, before realising that lead chloride is insoluble in water and I must have used an old wheel weight.

Oh my sides. Perhaps I should start a blog on here.

 

[mark_addy]

Still not managed to borrow the tiny blow lamp from work, because someone else has borrowed it 🙂 Never mind, I got the rollers rolling on the baritone, replaced some missing / squashed cork, and turned my attention to the alto. These rollers are brown / black Bakelite (from about 1925) I imagine; two rotate a lot (because the threads are fecked, even though they are siezed on the pins) and two rotate a bit (because they are seized on the pins, but the threads are not (yet) fecked).

Before I split the rollers off the pins with some kind of cutters I haven't made yet, and probably have to make some brown tufnol replacements (which is what I have lying about - or maybe nylon, white would look better than black on this silver-ish alto...I even have a stick of white PTFE but my blistering bebop pace is not that blistering) - is there anything else I should try first, I wonder? Heat via a soldering iron onto the very ends of the two pins which withdraw enough to access them, perhaps?

 

[PigSquealer]

Just keep soaking the stuck parts. Daily drops or submerged. It may take a week or three. I prefer “Kroil” for this situation.
Hopefully you cleaned the slot out and have a proper fitting screwdriver. Bad time to use one with a chisel point.
Heat can be applied to the touch area with caution. Heat then soak more. Be patient. Tend to other things and let it soak.
Bakelite or MOP can both be cracked off. Then extract the rod with smooth face pliers. Rollers are available at Dawks.

 

[mark_addy]

Thanks for your reply, that's encouraging. Yes, I have a drawer-full of dead-men's screwdrivers (relatives, widows, you know where to come with unwanted toolboxes) so I found one which fitted. In the same circumstances I inherited a paradoxically-rusty tin of 'Chesterton Rustolvo' so I'll try that as a penetrant. The ones with shot threads are not coming out without cracking the rollers off, I guess, as they go 'round and round' and they're in blind holes so I can't even make up a tiny punch. I wonder if I play this enough to be bothered that future wear would be taken up in the brass hole rather than in the roller itself. Whatever threads these were in Elkhart, if I go for it they are likely to be BA by the time I'm finished as I have a load of tiny taps and dies. (The donor in this case is still with us, but no longer making steam models).

So time to take it apart and maybe get out the Chinese alto for a bit. While it is apart, I notice two torn pads (though it plays OK for now). Are there views on here about the merits of single pads from apparently reputable suppliers, vs much cheaper whole sets from China on ebay? I mean, I know what views I might expect, but sometimes things are not as they seem, and if cheap ones are no good (like hacksaw blades and those skinny angle-grinder disks, from experience) it would be nice to know 'bad in what way'. Thanks folks.

 

[PigSquealer]

The ones with shot threads are not coming out without cracking the rollers off, I guess, as they go 'round and round' and they're in blind holes so I can't even make up a tiny punch.

Make a roller holder. Two 25mm x 10mm thick x width of roller blocks of nylon or soft wood. Measure the roller diameter. Select a drill bit that diameter. Clamp the two blocks together with a 0,50 shim between then drill the hole. This keeps the radius correct and provides a preset amount of squeeze. Keep soaking the roller… a week. Clamp the blocks on roller and then work the rod loose. Shock may help too. A brass punch tip made to go on end of electric engraving tool. Think jackhammer 😉

 

[PigSquealer]

Let me know before you attack the blind holes.

 

[mark_addy]

Ahhh

Make a roller holder. Two 25mm x 10mm thick x width of roller blocks of nylon or soft wood. Measure the roller diameter. Select a drill bit that diameter. Clamp the two blocks together with a 0,50 shim between then drill the hole. This keeps the radius correct and provides a preset amount of squeeze. Keep soaking the roller… a week. Clamp the blocks on roller and then work the rod loose. Shock may help too. A brass punch tip made to go on end of electric engraving tool. Think jackhammer 😉

- that's nice. Yep, can do that, and (not overdone) Mole grips (I think you call these something else) will clamp them. Thanks!

 

[PigSquealer]

Ahhh

- that's nice. Yep, can do that, and (not overdone) Mole grips (I think you call these something else) will clamp them. Thanks!

Using mole pliers straight on will crack them.
Drill the hole on end of block. Close to edge.

 

[PigSquealer]

Mole grips (I think you call these something else)

Vise Grips

 

[mark_addy]

Sorry, I should have been more clear. I meant that I will use Mole/vise grips to hold tight the shaped holders you described around the rollers themselves - very nice idea, thanks. I have some bits of hardwood which should yield some suitable offcuts, and a set of number drills (I wonder if you call them that) which should enable a close match to the roller OD. I think I even bought the number drills. But I don't think they were new 🙂

 

[PigSquealer]

#1 is likely too small @ .225 / 5.7mm
.240 / 6,1mm +/-
Also depending on the position of stuck roller you may need to increase the squeeze gap on tool.
I don’t favor the use of mole wrench for this.
Just for a visual. I can’t find my other set.

 

[mark_addy]

You're very kind (and putting more impetus behind this than I am! 🙂 ). You're quite right, we're into letters, not numbers - A and F it seems. And I take your point that leaning on the screwdriver will be easier if the thing is in a machine vice. I have a 'Nippy' in bits at the moment (common in the UK) - usually a nice one, but this looks like it came from a school as the thing is drilled to bits!

 

[mark_addy]

Alright, after a long soaking (not least, a few other things went wrong and needed looking at in the meantime) all 4 rollers are now rolling. RH keys and most of the pinkies are off, polishing commenced, and I noticed that D# and F pads are both fecked (although it played OK). D# I very much mangled, having been a bit too cautious with the heat gun, and F came out nicely in one piece as I got it rather warmer, having noted the shellac (?) starting to bubble a little at the edges. So I have diameters and thickness (very close to 4.0mm, though where you measure seems a bit arbitrary). They currently look like a set of 'mypads' in orangish leather with brown plastic reflectors, which I guess went on not too long before I bought it...34 years ago or thereabouts.

I have ordered a couple of replacement pads online, and I guess these will need sticking in with shellac. Are the sticks sold for scratch repair on furniture OK? I guess I heat the cup, rub some stick into it, heat again and then press new pad in. Or something else?

And - none of the other pads are torn, but some are a little crusty. Any tips for something appropriate to rub into them for cleaning?

Thanks for your (general you) support here - I am enjoying myself. And apologies that this is rather unsatisfying reading, as I can't provide pictures!

cheers
Mark