Gap Seals

[skippydiesel]

Good old Bunnings AeroSpace

 

 

[skippydiesel]

Sure Bruce Tuncks it is easy.

 

Go to Bunnings and look for "Norton Outdoor tape" it is a clearish tape with water resistant glue. It is about 50mm wide.

 

The tape is put where the aluminium hinge is ( ailerons on the top and flaps on the bottom of the surfaces, etc).

 

Y..............................................................

 

There is some tricks....(1) deflect the surface fully away from the hinge. This allows the surface to keep full deflection and the tape does

 

bunch up a bit but it is better to be sealed than worry about a small bump in the tape ( which seems to flatten in the air).

 

                                .....(2) If possible extend the tape slightly past the end of the surface and round off the ends ( stops it peeling off).

 

I've probably forgotten something... let me know how you go.

 

"Forgotten something"  - could be this only works for offset hinges ie if your flap/elevator/rudder is a roughly airfoil shape rotating/moving around the centre of the blunt end , the tape is likely to have a negative impact on the free movement of the control surface - or have I missed something??

 

 

[Thruster88]

One thing, remember that dust will stick to the tape and look $hit after a while. 

 

 

 

20180922_162333_1.mp4

 

[Raytol]

Hi Skippy,

 

I was specifically referring to a Lancair 360's control surfaces which are all hinged with aluminium extruded hinge.

 

I have done centre mounted hinges as well but they are a lot harder!

 

I have never seen dust stick to the outer surface of the tape.

 

I forgot to mention that the Lancair flaps are hinged on the bottom surface and the water and dust can stay so you

 

need to lubricate the hinge more than normal.

 

 

[skippydiesel]

Hi Skippy,

 

I was specifically referring to a Lancair 360's control surfaces which are all hinged with aluminium extruded hinge.

 

I have done centre mounted hinges as well but they are a lot harder!

 

I have never seen dust stick to the outer surface of the tape.

 

I forgot to mention that the Lancair flaps are hinged on the bottom surface and the water and dust can stay so you

 

need to lubricate the hinge more than normal.

 

Yes I understood what sort of hinge system (not exclusive to Lancair ) you were referring to.

 

Please describe with photos/diagrams how your tape can be applied to " centre mounted hinges" without restricting movement.

 

 

[Bruce Tuncks]

Years ago, I used the wrong type of aileron tape on an Astir glider. The tape had been supplied with my Jabiru kit and it was a white 2" wide semi-cloth tape, cheaper and wider than the proper German cloth tape. You can buy very similar stuff at Supercheap. It has a shiny plastic look.

 

I put it on properly, and checked that the ailerons moved fully, but over the summer, the tape shrank and very gradually began to restrict the aileron movement.  Tape on the top surface gets more exposure than underside tape.

 

This shrinkage was not noticed by the low-hour pilots who flew that glider, as they could still do "full" movement because the pushrods flexed.

 

I felt glad to notice this myself and fix it before anybody else noticed.

 

 

[facthunter]

"Proper" gap seals are not tapes, necessarily. The best ones close the gaps by almost eliminating them and modifying the airflow that does pass through  any remaining gap.... Usually the design is not credited with any  "documented " and calibrated improvement in the POH, but the way the plane flys is  improved. This is mainly for VMC(a) with assymetric power. Unless engines are contra rotating one of them is more critical than the other.

 

   I wouldn't be bothered taping gaps with duct tape or such. As I said earlier you need to be able to inspect hinges etc. Nev

 

 

[Bruce Tuncks]

Well you might live longer but you would not win at Reno Nev.

 

 

[facthunter]

At the speed they go I wouldn't think adhesive tape would be reliable enough.. At 400 MPH water drops pit aluminium, so how long would tape last at those speeds?  Nev

 

 

[jetjr]

On the elevator of a 120kt Jabiru it lasts many years, UV cracks it eventually

 

The outdoor tape is clear

 

 

[facthunter]

 On the Tiger Moths they just left a section of undoped loose canvas. Looks %#$@  Nev

 

 

[skippydiesel]

On the elevator of a 120kt Jabiru it lasts many years, UV cracks it eventually

 

The outdoor tape is clear

 

 Just so and if you want to use an aircraft tape  (mainly for gliders) there are several to choose from (white) in several widths - last for years. 

 

Check this lot out:

 

http://www.cumulus-soaring.com/bowlus.htm