Light weight tube

[skippydiesel]

Hi All,

 

I need to replace a hot air duct. The critical dimensions are ID & length.

 

ID 61.6 mm x Length 550 mm

 

Fitting over existing structures/supports is the reason for the ID (could probably get away with a little bigger, but smaller would be problematic). Original tube had an aproximately 1 mm wall thickness.

 

I think OD is going to be around 2.5 in, in the Devil's measurement system that most suppliers seem to use.

 

Note: measuring device (& operator) not as precise as might be hoped.

 

Have tried all the aircraft suppliers of tube, that come up on Google - no joy.

 

Tried a few commercial aluminium suppliers - min wall thickness 2 -3 mm in this size pipe, making ID way to small .

 

Currently corresponding with a custom intercooler builder but not holding out much hope.

 

Suggestions welcome

[turboplanner]

14 minutes ago, skippydiesel said:

Hi All,

 

I need to replace a hot air duct. The critical dimensions are ID & length.

 

ID 61.6 mm x Length 550 mm

 

Fitting over existing structures/supports is the reason for the ID (could probably get away with a little bigger, but smaller would be problematic). Original tube had an aproximately 1 mm wall thickness.

 

I think OD is going to be around 2.5 in, in the Devil's measurement system that most suppliers seem to use.

 

Note: measuring device (& operator) not as precise as might be hoped.

 

Have tried all the aircraft suppliers of tube, that come up on Google - no joy.

 

Tried a few commercial aluminium suppliers - min wall thickness 2 -3 mm in this size pipe, making ID way to small .

 

Currently corresponding with a custom intercooler builder but not holding out much hope.

 

Suggestions welcome

Laminate an FRP tube; make 2 halves bolted together.

[Thruster88]

Why not scat hose as used in aircraft?

[skippydiesel]

2 hours ago, Thruster88 said:

Why not scat hose as used in aircraft?

Thanks Thruster,

 

3 hours ago, turboplanner said:

Laminate an FRP tube; make 2 halves bolted together.

This is an part of an exhaust extractor system. Dont think SCAT would tolerate the heat for very long. 

[skippydiesel]

3 hours ago, turboplanner said:

Laminate an FRP tube; make 2 halves bolted together.

Thanks Turbo,

 

The original pipe (that I damaged) is metal - I think aluminium alloy but may be something else.  Came with the partially completed project, so I assume sourced in AU.

[onetrack]

Skippy, here you go, from our finest quality aircraft parts supplier...... 😄

 

https://www.aliexpress.com/i/33009213721.html

[rodgerc]

[spacesailor]

I did toy with the idea of ' aluminium tube " instead of rubber hose ( oil-cooling ) to the oil filter , as a weight saver,  plus heat extraction .

Put into the " too hard basket " .

spacesailor

[Thruster88]

So this sounds like an exhaust augmented cooling system? One option would be to roll the desired material  and secure with hose clamps or tig weld.

[skippydiesel]

12 hours ago, onetrack said:

Skippy, here you go, from our finest quality aircraft parts supplier...... 😄

 

https://www.aliexpress.com/i/33009213721.html

There's a thought - Existing tube solid - Will dwell on this idea. Thanks

[skippydiesel]

11 hours ago, rodgerc said:

Thanks Roger - Most of this pipe has the wrong ID but as I said I am talking to a custom intercooler manufacturer who may be able to assist me.

[skippydiesel]

1 hour ago, Thruster88 said:

So this sounds like an exhaust augmented cooling system? One option would be to roll the desired material  and secure with hose clamps or tig weld.

Good thought Thruster.  Tig weld would be the way to go. Any suggestions as to who might provide such a service?

[Thruster88]

I know a good tig welder however I would favor the hose clamps because this will allow the aluminium to grip the underlying steel? support structure. Many certified aircraft cabin heat muffs on the exhaust are done this way, PA28 etc. Just allow some over lap at the join. 

[Marty_d]

Sorry Skippy, my fat fingers somehow managed to rate this topic. Wasn't trying to.

[skippydiesel]

26 minutes ago, Marty_d said:

Sorry Skippy, my fat fingers somehow managed to rate this topic. Wasn't trying to.

Dont be sorry, any excuse for a chat😈

[skippydiesel]

56 minutes ago, Thruster88 said:

I know a good tig welder however I would favor the hose clamps because this will allow the aluminium to grip the underlying steel? support structure. Many certified aircraft cabin heat muffs on the exhaust are done this way, PA28 etc. Just allow some over lap at the join. 

The duct (part of an exhaust extraction system) need to be reasonably air tight or wont work. Overlap might do the trick, clamps add significantly to weight but a lot cheaper than welder time.

[skippydiesel]

Seems that 61.6 ID rolling is considered to be more of a hobby than a commercial service.

 

I can purchase a 610mm "slip roller" for $473. Tad expensive for a one off. Anyone out there got one I can borrow/use/pay you to do the job.

[danny_galaga]

19 hours ago, onetrack said:

Skippy, here you go, from our finest quality aircraft parts supplier...... 😄

 

https://www.aliexpress.com/i/33009213721.html

Being the Xmas month, and the fact AliExpress sellers use any old fly by night couriers at the receiver end, you should get it by early February if you order now 😄

[skippydiesel]

55 minutes ago, danny_galaga said:

Being the Xmas month, and the fact AliExpress sellers use any old fly by night couriers at the receiver end, you should get it by early February if you order now 😄

Tempting Danny.

 

Will hold out a little longer in the hope of finding  a "stiff" pipe.

 

Thanks