Fault diagnostic - leakage or other explanation?

[MarkP]

Hi

just about to do some work on an old flute I picked up (mid 19th century 8 key) but I have a question for advice before going any further... Some basic diagnostics from a 10 minute inspection...

Very nice looking flute apart from one full length hairline crack to the barrel which has been repaired (looks like a good job, seems sound).

Fully lined head, tight fitting tuning slide.

Sections are tight fitting and line up nicely (a little too tight if you ask me, maybe a bit of thread to remove and then test with plumber's tape for now, maybe cork them later).

Ferruls are substantial and well fitted, no loose keys, all springs intact. Wood blocks and pins all in good order.

G# pad is missing but taping over seems to get the G in tune. Other pads also need replacing.

Flute then plays very nicely in tune A440Hz over the top section (C# down to G) with the slide only minimally adjusted (a few millimeters)

Cnat cross-fingered (0XX0X0X) also plays very nicely to digital tuner... looking good so far...BUT...

No proper tone is blowable with hole 4 covered (either F# and below, or d and above) - almost silent, hard to tell even the tuning, just a whisper.

Easy I think... tape over the mid section key holes with the dodgy pads and try again to see what needs fixing... but this doesn't seem to make any difference (maybe try again this evening with better tape and pay more attention to detail?)

Before I think about re-padding, does this seem the first thing to look at or could there be something I haven't seen that is going wrong at the joint of the main sections (between holes 3 and 4) or the ombachure?

Any advice for the second inspection?

Cheers, Mark

[jemtheflute]

I think you're on the right track, Mark. Pad and joint-lapping leaks or just possibly socket cracks are the first suspects. I doubt the embouchure will have anything to do with it. Do suck tests on the individual joints, then on each combination of two joints, etc. Also check the tuning slide - it feeling tight fitting doesn't necessarily mean it is airtight. Suck test the barrel and head separately (stopper cork is another obvious suspect leak-source) and together.

Oh, and if you haven't, have a look down the bore and make sure there are no foreign bodies!!!!!!

Next step is to remove all keys and block the holes with blutack or plasticine and try again.

BTW, try C nat oxoxxx, (, = Eb key open) - though until you get things sealed properly such tests are not conclusive.

Any chance of some pictures?

Keep us posted.

[MarkP]

thanks for the quick response Jem

stopper cork is another obvious suspect leak-source

forgot to mention that this was a little loose (I tried just taping round the head end). Would a leak to the cork or tuning slide have a general effect across the instrument or could it account for the sudden difference between top and bottom sections?

possibly socket cracks are the first suspects

Will also inspect more closely for hairlines here. I guess that's more of a problem if so.

Oh, and if you haven't, have a look down the bore and make sure there are no foreign bodies!!!!!!

fair point, I did that

Any chance of some pictures?

Will work on that if I get time (where's an easy place to post them so they link from here?)

Thanks again

[plunk111]

Don't know if you've tried this as it's kinda obvious, but have you done a "suck test"? You cover the three holes in a section with your fingers, push the back against your hand, put your lips over the other end, and suck. If you don't get a "pop" (or a lip-hickey!), you have a leak. I went through the same thing with an eBay flute... You might also check the posts (assuming the keys are post-mounted).

I second the pictures request...

Pat

[jemtheflute]

Hi Mark. Yes, a leaky stopper or slide will affect the whole flute, but the more tone-holes you are covering, the worse the effect. That said, one can usually get most of the 2nd 8ve on even quite a leaky flute, if at reduced tone and response and volume. An abrupt loss of down-to-there decent tone as you go down scale may well indicate another problem.

Taping around the crown is unlikely to block a stopper-cork leak. Pull it out and grease it thoroughly, then reinsert it and suck test that. If it still leaks, wrap some PTFE tape around it and repeat. Don't force it in with anything too tight, but if it does get stuck it isn't likely to do any damage in a lined head and you just have to use a solid dowel and a bit more oomph to push it back out. Remember it is the cork inside, not the crown that has to provide a seal, and in the correct position.

You most likely have a whole bunch of smaller issues and need to eradicate them one by one. Start from the head end and work down-tube as problems at the head affect all else and disrupt the elimination process further down if not fixed first.

As for pictures, there is a guide to how to post them here on C&F somewhere in the Flute Pictures thread/searchable on the Forum. find a picture host service and then put the BB link codes in your post here, but remember to reduce the images to under 700 pixel width or they'll bump the pages here too wide!

[Cathy Wilde]

Dont' forget to check the sockets for chips, cracks, missing chunks, etc. as well. The tenons don't always tell the whole story .... Good luck, and have fun!

[MarkP]

Progress report:

applied a light almond oil inside and out all sections and removed excess before going to work.

came back and dug out my ruler, camera, plumber's tape, blutac and tools after work, so here's a second installment (sorry, I have photos of all this but you'll have to wait)

Procedure:

Cocus or Rosewood 8 key, no maker's mark. Foot keywork suggests mid 19th century (c 1850-60 perhaps?)

Head - fully lined end to end, excellent quality of construction, brass neatly cut to embachure.
Head cork was loose fitting, wooden screw thread in excellent condition.
Cork grease applied - suction test OK (but applied some plumber's tape to improve temporarily)
Adjust thread to 19mm from embachure as a starting point

Barrell - inspected, no additional cracks
Suction test OK
Grease tuning slide, assemble head and suction test - OK

Inspect main section for cracks and chips - all in good shape
H1 - 7mm (gap 35mm)
H2 - 8mm (gap 35mm)
H3 - 7mm (I'm measuring across the flute not lengthways for diameter here)

Remove holding pins and keys, inspect pads (two worn, G# missing), springs (fine)
Inspect wooden block work and pad seats (well defined and clean, no cracks)
Remove excess twine from tenons, inspect old corking and grease (in good condition)
Block all holes and suction test - OK
Refit keys and test springs
Fit blutac as temporary G# pad!
Plumber's tape to tenon joints, assemble and test - it works! (phew)

Inspect lower section
H4 = 9mm (gap 58mm)
H5 = 10mm (gap 32mm)
H6 = 7mm

No time to inspect foot or do more dis-assembly. More fun to blow it.

Allowing for some head tuning it should play very well when all pads are sealed. Minimal work required and very fine looking instrument. Very light and agile to play, lively in the second octave (low end suffering from minor leaks I suspect but no problem to play a respectable D now). Seems fast on ornaments. Some keys may be a little awkward but early days.

Will try to post photos tomorrow maybe.

Thanks for the advice.

[jemtheflute]

Well done indeed! Remember the Eb key affects the Ds too if it is leaking, and also the clearance of the C# key's plug or pad - if it doesn't lift clear enough of its bed when at rest it will shade and flatten and weaken the D, ditto the low c too, but less seriously.

It sounds like the stopper cork was your biggest problem, though the missing G# pad won't have helped. In my experience it is rare for an antique cork stopper to be worth retaining, even if it hasn't decayed beyond re-use anyway. I almost always replace them and have written somewhere here in the past about how I use modern plastic wine "corks" rather than real cork.

Jon C has a nice sequence of photos on his Facebook page showing how he replaces a stopper with real cork, though it is much easier if you have and use a lathe as he does: filing/sanding a cork down to size by hand is a bit of a bum job, hence my use of the plastic ones.........

[MarkP]

OK, you can have some pictures. You'll get them one section at a time as per the inspection above. In the words of Ralph Harris, 'can you guess what it is yet?'

Here's the head...

[MarkP]

...and now the cracked/repaired barrel (a sound fixing job but could be better on the cosmetics)




...you'll have to wait for the next installment

[jemtheflute]

Mmmm. The style of the ferrule rings, the fairly copper-rich, yellowish German Silver, the profile of the crown "mushroom" are very Metzler-ish, as is the lustrous reddish cocus...... If the flute is unstamped externally, I'd rather expect to find an AL stamp on the underside of at least one key.......

(BTW, he's Rolf Harris )

[Aanvil]

...very Metzler-ish...

That was my very first impression.

I concur.

[MarkP]

So, we have two votes for Metzler then. I'll maintain the suspense. Any alternative options?

To recap on the diagnostic and temporary fixes: we now have a cleaned up head (with a patched up cork) and barrel (with repaired crack and greased slide) that passes suction test. So far so good.

For today's installment we turn to the first keyed section. Here you can see the condition of the tenons (good), the block work, pad seats, keys and pins. You can also see the temporary fixes for suction text (to compensate for leaky tenon corks and missing G# pad) and the overall layout of the section. You have some of the scale dimensions higher up the thread.







I'll add that none of the three keys on this section are marked in any obvious way. Next section tomorrow. Wait til we get to the foot. The suspense is killing me...

[jemtheflute]

Pointed arm-to-cup attachments, very shallow pad cups, slightly pointy droplet shape to the Bb touch, a dinky, very short little G# key....... consistent so far, very Liddlesome!

If the Eb key does not have an assymetrically enlarged lower lobe and both it and the long F don't have little upward curls to their touches........ I'll eat my......

[MarkP]

Glad to see a man so confident in his opinion. Let's hope you're right and it's not that cocus and bone flute you're eating in the Avatar.

Off to the pub to play some music rather than chatting but I managed time for the next installment, so we turn to the lower (right hand) section - and can verify one part of Jem's hypothesis (the up curl on the long F key).

Inspection of the tenons reveals a small concern about the hint of a crack in the female socket (barely visible to the eye but the camera's macro and flash shows it). I mentioned the overtight threading in the first post and this might be sign that it has created a weakness here. On the plus side, the ferrules are substantial (an 11mm overlap on the wood).

As previously, you can see the condition of block, seat and keywork (no marks on the keys in this section either).

Finally you have the cleaned and assembled section again with ruler.





So, is the money still on a Metzler and Liddle combination? Is there a sting in the tail (foot)...?