corosion during storage

There is a report on serious corrosion in PIK 20 s due to
condensation during storage. The rod ends in particular are
susceptible.
One recommendation is that the trailer be sealed with silica gel inside

http://trafi.mailpv.net/a/s/95652244...0a2ef4/1825275

I am skeptical that a trailer can be sealed well enough to prevent
complete air changes due to pressure changes during say 6 mo of
storage.

Has anybody tried this?

John F

I have never tried to fully seal a trailer.
I "have" sealed large areas, similar to a trailer.

How long must it sit?
Can it be inspected now and then?

Best is in a rather dry location, not sitting outside.
There are products like "DampRid" which are are tubs of a water absorber found at many local places.....grocery stores, hardware stores, big box places like Walmart/Lowes/Home Depot, etc.

How about, instead of trying to seal it, be proactive and apply corrosion-inhibiting materials? Grease or oil of some sort. The interiors of aluminum airplanes are sometimes sprayed with such.

And why would the PIK20 be more susceptible than other types? If the geometry inside of it causes condensation to specifically drip onto some fittings, perhaps can add barriers to that dripping. E.g., a bead of caulking a few inches uphill from that spot may cause the dripping to happen where it is harmless.

On Tuesday, April 17, 2018 at 9:43:55 AM UTC-7, john firth wrote:
There is a report on serious corrosion in PIK 20 s due to
condensation during storage. The rod ends in particular are
susceptible.
One recommendation is that the trailer be sealed with silica gel inside

http://trafi.mailpv.net/a/s/95652244...0a2ef4/1825275

I am skeptical that a trailer can be sealed well enough to prevent
complete air changes due to pressure changes during say 6 mo of
storage.

Has anybody tried this?

John F

From dealing with this problem on boats, I can virtually guarantee that sealing, or silica gel, will do little good. On a boat, I run a dehumidifier 24x7, as well sealed as I can get it (which is much better than a typical glider trailer) in a humid climate it will produce several liters of condensate per day. That will very quickly saturate any moisture absorbing materials you might use. Even if you close the trailer and tape all open seams (which might actually be possible on a PIK tube trailer) the initial load of moisture when you closed the door is considerable.

On Tuesday, April 17, 2018 at 12:43:55 PM UTC-4, john firth wrote:
There is a report on serious corrosion in PIK 20 s due to
condensation during storage. The rod ends in particular are
susceptible.
One recommendation is that the trailer be sealed with silica gel inside

http://trafi.mailpv.net/a/s/95652244...0a2ef4/1825275

I am skeptical that a trailer can be sealed well enough to prevent
complete air changes due to pressure changes during say 6 mo of
storage.

Has anybody tried this?

John F

The PIK 20 is one of the older gliders which was produced in significant
numbers; nothing specially bad about the hardware; that just happened to be
an example which was found by careful inspection. Maybe we'll hear more.

JMF

Would it be feasible to use a humidistat to control a small electric space heater inside a partially sealed glider trailer? I'm thinking that you just need to lower the dewpoint of the air inside the glider trailer below the temperature of the glider. Maybe raise the temperature inside the trailer 10d F above the temperature outside of the trailer?

On Tuesday, 17 April 2018 19:43:55 UTC+3, john firth wrote:
There is a report on serious corrosion in PIK 20 s due to
condensation during storage. The rod ends in particular are
susceptible.
One recommendation is that the trailer be sealed with silica gel inside

http://trafi.mailpv.net/a/s/95652244...0a2ef4/1825275

I am skeptical that a trailer can be sealed well enough to prevent
complete air changes due to pressure changes during say 6 mo of
storage.

Has anybody tried this?

John F

I believe in this case the glider was outside trough UK winter (mostly rain). This is not normal at all, especially for PIK which uses hardware that is quite high quality.

It is not a question of what type it is or not. As gliders grow older, they
will show wear. And corrosion sometimes too. Mostly depends on how it has
been treated and stored, but also on for instance water bags being tight,
if it has been sitting outside for some time tied down etc.

The PIK-20 case is not alone. I have found similar corrosion issues in the
wings of a Standard Libelle and DG300. A thorough annual will usually flush
out any issues. If in doubt, use a boroscope to access hard-to-get-to
areas. Such as the wings from the opening inside the airbrake boxes.

At 04:42 18 April 2018, krasw wrote:
On Tuesday, 17 April 2018 19:43:55 UTC+3, john firth wrote:
There is a report on serious corrosion in PIK 20 s due to
condensation during storage. The rod ends in particular are
susceptible.
One recommendation is that the trailer be sealed with silica gel inside


http://trafi.mailpv.net/a/s/95652244-
7673938ea61c6658441d4f5c490a2ef4/1825275

I am skeptical that a trailer can be sealed well enough to prevent
complete air changes due to pressure changes during say 6 mo of
storage.

Has anybody tried this?

John F

I believe in this case the glider was outside trough UK winter (mostly
rain). This is not normal at all, especially for PIK which uses hardware
that is quite high quality.

The original BGA report on the PIK (complete with more horror pictures)
is he

https://members.gliding.co.uk/library/tns/tns-2-2016/

Note that the trailer is described as damp and unventilated. Note also
that another PIK in a ventilated trailer on the same site was unaffected.

On Wed, 18 Apr 2018 07:05:34 +0000, Eric Munk wrote:

It is not a question of what type it is or not. As gliders grow older,
they will show wear. And corrosion sometimes too. Mostly depends on how
it has been treated and stored, but also on for instance water bags
being tight, if it has been sitting outside for some time tied down etc.

The PIK-20 case is not alone. I have found similar corrosion issues in
the wings of a Standard Libelle and DG300. A thorough annual will
usually flush out any issues. If in doubt, use a boroscope to access
hard-to-get-to areas. Such as the wings from the opening inside the
airbrake boxes.

I get the impression that this winter, in the UK, has been worse than
usual for corrosion. It affected my Libelle's undercarriage more than I
expected (corrosion on the wheel, flaking paint on otherwise untouched U/
C legs) despite being in a dry grain barn for most of the winter.


--
Martin | martin at
Gregorie | gregorie dot org