Delrin flutes with metal tuning slides + unlined headjoints

[Loren]

I've tried a number of delrin/acetal flutes over the years, however I can't recall off-hand which, if any, had a full metal tuning slide, but an unlined headjoint. Can anyone help jog my memory here? (And yes, I know that having a metal tuning slide technically means the head is partially lined.)

TIA,

Loren

[m31]

Paddy Ward.

[kkrell]

Cochran flutes.

[eilam]

seery (i'm pretty sure)

[Terry McGee]

I'll admit to not understanding the question confidently, Loren. If you mean an otherwise unlined head coupled with a metal tuning slide, then count mine in.

I.E. "partial" tuning slide, the remainder of the head being unlined.

Terry

[Jayhawk]

As Eilam said, Des Seery's delrin flutes are made that way.

Eric

[Loren]

Thanks all, much appreciated.

Yes Terry, you got my meaning - just enough lining in the headjoint to accommodate the slide parts. Just out of curiosity, did you find you had to use a different adhesive for the delrin/metal bond, than you do for the wood/metal bond on a standard flute Terry?

Loren

[Gabriel]

Even though I'm not Terry, I'm feeling bold enough to reply: I haven't been successful with glueing delrin to metal (i.e. brass) yet, the stuff I usually use for wood-metal junctions (a two component epoxy resin that can easily be "unglued" by gently applying heat) doesn't bond and superglue doesn't work either. I have been told that Delrin needs a very special glue from 3M that is said to be very expensive - but haven't investigated further as I suppose my first Delrin flute also will be the last one...don't like that stuff.

[jemtheflute]

Gabriel, have you thought of trying Ebonite? It is supposedly smelly to work but otherwise good (was that something Terry wrote somewhere?)..... and it is available in suitable flute joint type cylinders, even with a pre-drilled narrow centre bore, I believe. I think I've mused about this before, and since then M&E have started producing (or at least importing and doctoring) Ebonite flutes. As far as I know Ebonite is generally non-allergenic (though I suppose latex allergy sufferers would have to be wary) and all the things it was praised for as a flute material in the C19th are still true plus it no longer has the chemical instability issues of their material. It still gets used for student level clarinets, oboes and even piccolos, but hasn't been used seriously in Europe for flutes since about the 1930s. It could certainly be used with a part-lined head tuning slide configuration. I remember finding a German manufacturer of Ebonite rod last time I did a bit of research on this, though I can't quickly find them again to post a link.

[Maihcol]

If you try working delrin using the tools and techniques you use on wood, you'll have a hard time. It took me a long time to get the hang of it but now I find it ok - and it's all I use at the moment.

I also use the partially lined head on my delrin flutes - I think most makers do. Whatever glue you decide to use (I use the professional grade 24 hour araldite on mine), you'll need to roughen the bonding surfaces first - and/or turn grooves in the metal bonding surface - which is what I do on my whistles before bonding the delrin mouthpiece and slide to the aluminium bodies. The resin then solidifies and beds into the scratches in the delrin and grips the raised fibres. The area of the bonding surfaces is also relatively large when bonding slides, which helps a lot and you can also make the metal inner tubes for the flute slides longer to improve that. The outer slide tube in the barrel already has plenty of bonding surface. You then get a bond with a lot of mechanical strength which you'll need to use a considerable amount of heat to get apart.

Garry

[Terry McGee]

Thanks all, much appreciated.

Yes Terry, you got my meaning - just enough lining in the headjoint to accommodate the slide parts. Just out of curiosity, did you find you had to use a different adhesive for the delrin/metal bond, than you do for the wood/metal bond on a standard flute Terry?

Loren

I'll admit to expediency here, Loren. I just use the same approach I use with wood, my New Improved Tuning Slide arrangement, where the slide is held in the wood (or Delrin) by a buffer layer of cork. So my slide isn't glued in, and can be easily removed if say damaged in a fall.

There shouldn't be the same imperative to do this with Delrin as with wood as, as far as I know, Delrin shouldn't shrink with time. (I only assume this, but it's probably a safe assumption. Some earlier plastics, eg the acetate used in coating acetate recording discs back in the 50's, did shrink when their plasticiser evaporated, with subsequent dramatic results for the recordings on them!)

But, assuming I'm right that no buffering should be needed with Delrin, why use adhesive at all? Why not make it a tight fit and press them together? If the slide got damaged in a fall, it could probably still be removed by heat, or bored out if totally mangled.

Terry

[Jon C.]

Thanks all, much appreciated.

Yes Terry, you got my meaning - just enough lining in the headjoint to accommodate the slide parts. Just out of curiosity, did you find you had to use a different adhesive for the delrin/metal bond, than you do for the wood/metal bond on a standard flute Terry?

Loren

I'll admit to expediency here, Loren. I just use the same approach I use with wood, my New Improved Tuning Slide arrangement, where the slide is held in the wood (or Delrin) by a buffer layer of cork. So my slide isn't glued in, and can be easily removed if say damaged in a fall.

There shouldn't be the same imperative to do this with Delrin as with wood as, as far as I know, Delrin shouldn't shrink with time. (I only assume this, but it's probably a safe assumption. Some earlier plastics, eg the acetate used in coating acetate recording discs back in the 50's, did shrink when their plasticiser evaporated, with subsequent dramatic results for the recordings on them!)

But, assuming I'm right that no buffering should be needed with Delrin, why use adhesive at all? Why not make it a tight fit and press them together? If the slide got damaged in a fall, it could probably still be removed by heat, or bored out if totally mangled.

Terry

That is right, I have pressed in the slide, scoring it like they did in the old days, with a razor knife, then press it in. If the delrin is scored like Garry said, it will key in the glue joint.

[talasiga]

seery (i'm pretty sure)

yes, about 12 years ago my seery blackwood cracked headjoint and barrel.
( I had neglected it for about a year while in hospital and recuperating).

Desi sent me Delrin replacement and the headjoint is indeed unlined