Hard wax v/s liquid wax

El martes, 28 de agosto de 2018, 12:27:55 (UTC-3), Soartech escribió:
Please name a few brands and types of typical "hard wax" for use on gelcoat.
Thanks.

According to my research, pure brazilian "Carnauba" seems to be good for the job.

On Tuesday, August 28, 2018 at 6:30:22 AM UTC-6, FranCP wrote:
Hi,
Can hard wax be replaced by liquid wax application? Of course silicon free, as well as other harmfull adds.
Although i've seen guys maintaining their gliders purely on applying liquid wax regularly, i guess it wont seal & protect the gelcoat as well as a good anual hard wax buffing.
¿Any advice?
Thanks

A golf ball has many small dimples over its surface, to make it more "slippery". So how would this principle apply to a glider?

On Tue, 28 Aug 2018 19:50:19 -0700, John Foster wrote:

On Tuesday, August 28, 2018 at 6:30:22 AM UTC-6, FranCP wrote:
Hi,
Can hard wax be replaced by liquid wax application? Of course silicon
free, as well as other harmfull adds.
Although i've seen guys maintaining their gliders purely on applying
liquid wax regularly, i guess it wont seal & protect the gelcoat as
well as a good anual hard wax buffing.
¿Any advice?
Thanks

A golf ball has many small dimples over its surface, to make it more
"slippery". So how would this principle apply to a glider?

Read up on turbulators. They're not needed on modern airfoils, but were
useful for preventing flow separations on older wing sections (Wortmann)
and at the hinges of control surfaces:

- I've seen turbulators immediately ahead of the aileron hinges on
Discus 1s

- fitting them ahead of the rudder hinge on a Grob G.103 is said to
improve rudder response

- my Std Libelle has full span turbulators under the wing, just in front
of the undercambered part of the lower surface.
Streifneder sells them.

... and of course they work really well to improve airflow at low Reynolds
numbers (40,000 - 100,000).

Just ask any serious free flight model flyer. The first F1A I built with
a D-box wing structure flew like a dog until I fitted thread turbulators
where the rear of the leading edge and the front of the main spar were on
my previous successful open-structure models with entirely tissue covered
wings.


--
Martin | martin at
Gregorie | gregorie dot org

Le mercredi 29 août 2018 13:42:25 UTC+2, Martin Gregorie a écritÂ*:

Read up on turbulators. They're not needed on modern airfoils,

Except that ALL modern airfoils use turbulators.

On Wednesday, August 29, 2018 at 7:20:29 AM UTC-5, Tango Whisky wrote:
Le mercredi 29 août 2018 13:42:25 UTC+2, Martin Gregorie a écritÂ*:

Read up on turbulators. They're not needed on modern airfoils,

Except that ALL modern airfoils use turbulators.

I am pretty certain that on my ASW-27B the only turbulators on the wings are small 2cm wide sections just in front of the underside NACA vents which pressurize the ailerons and flaps. I can only guess at the aerodynamics of the turbulator's purpose here but this might be an example of this particular modern airfoil NOT needing turbulators (per Schleicher at least). ;-)

Remind me - how did we get from talking about waxing onto the subject of turbulators? ;-)

On Thu, 30 Aug 2018 06:59:34 -0700, OHM Ω http://aviation.derosaweb.net
wrote:

Remind me - how did we get from talking about waxing onto the subject of
turbulators? ;-)

....via the Dimpled Golfball highway


--
Martin | martin at
Gregorie | gregorie dot org

Le jeudi 30 août 2018 15:59:36 UTC+2, OHM Ω http://aviation.derosaweb.net a écritÂ*:
On Wednesday, August 29, 2018 at 7:20:29 AM UTC-5, Tango Whisky wrote:
Le mercredi 29 août 2018 13:42:25 UTC+2, Martin Gregorie a écritÂ*:

Read up on turbulators. They're not needed on modern airfoils,

Except that ALL modern airfoils use turbulators.

I am pretty certain that on my ASW-27B the only turbulators on the wings are small 2cm wide sections just in front of the underside NACA vents which pressurize the ailerons and flaps. I can only guess at the aerodynamics of the turbulator's purpose here but this might be an example of this particular modern airfoil NOT needing turbulators (per Schleicher at least). ;-)

Turbulators are either zig-zag / dimple tapes (all non-Schleicher), or blow holes (Schleicher). Both do the same job.

I am pretty certain that on my ASW-27B the only turbulators on the
wings
ar=
e small 2cm wide sections just in front of the underside NACA vents
which
p=
ressurize the ailerons and flaps. I can only guess at the aerodynamics
of
=
the turbulator's purpose here but this might be an example of this
particul=
ar modern airfoil NOT needing turbulators (per Schleicher at least).
;-)


And what is the purpose of pressurizing the ailerons and flaps??
Could it be to actually pressurize the blow hole turbulators (which
some manufacturers have substituted Z-tape or dimple tape for
because of ease of construction and reduced maintenance
issues)????

RO

On Thursday, August 30, 2018 at 9:59:36 AM UTC-4, OHM Ω http://aviation.derosaweb.net wrote:
On Wednesday, August 29, 2018 at 7:20:29 AM UTC-5, Tango Whisky wrote:
Le mercredi 29 août 2018 13:42:25 UTC+2, Martin Gregorie a écritÂ*:

Read up on turbulators. They're not needed on modern airfoils,

Except that ALL modern airfoils use turbulators.

I am pretty certain that on my ASW-27B the only turbulators on the wings are small 2cm wide sections just in front of the underside NACA vents which pressurize the ailerons and flaps. I can only guess at the aerodynamics of the turbulator's purpose here but this might be an example of this particular modern airfoil NOT needing turbulators (per Schleicher at least). ;-)

Remind me - how did we get from talking about waxing onto the subject of turbulators? ;-)

Your glider uses blow turbulators, located at the proper point, which happens to be on the control surfaces.
To ensure full flow and pressure to the NACA inlets Schleicher puts double thickness zig zag tape in front of the inlets. This trips the flow to turbulent and ensures the effectiveness of the NACA inlets as a supply source.
UH

On Thursday, August 30, 2018 at 2:59:36 PM UTC+1, OHM Ω http://aviation.derosaweb.net wrote:
On Wednesday, August 29, 2018 at 7:20:29 AM UTC-5, Tango Whisky wrote:
Le mercredi 29 août 2018 13:42:25 UTC+2, Martin Gregorie a écritÂ*:

Read up on turbulators. They're not needed on modern airfoils,

Except that ALL modern airfoils use turbulators.

I am pretty certain that on my ASW-27B the only turbulators on the wings are small 2cm wide sections just in front of the underside NACA vents which pressurize the ailerons and flaps. I can only guess at the aerodynamics of the turbulator's purpose here but this might be an example of this particular modern airfoil NOT needing turbulators (per Schleicher at least). ;-)

Remind me - how did we get from talking about waxing onto the subject of turbulators? ;-)

With modern glider aerofoils having such long laminar flow on the lower surface the blowholes on the various ASW-type ailerons/flaps *are* the turbulators on the wing aerofoil. Same as the JS aerofoil with blowhole turbulators at 95% chord which happens to lie on the flaperons.