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1. 08:45 AM - Re: YAK Pneumatic Lubricant (long post) (Cliff Coy)
2. 10:43 AM - Re: YAK Pneumatic Lubricant (long post) (Jan Mevis)
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| Subject: | Re: YAK Pneumatic Lubricant (long post) |
Don't know how or why I received this email thread but...
We've been lubricating actuators, uplocks, and valves for something
like....20 years with Royco 43 Pneumatic system grease with excellent
results.
Royco only sells No.43 in 6.5# cans but commercially available greases
meeting the MIL-G-4343 Pneumatic System Grease specification are sold under
the names JetLube No.33 or Molycote 55M.
The glycerin/alcohol mixture was never meant as a lubricant--merely the
final drying step after the air/water separator and filter assemblies
before the pop-off valve.
As is evidenced by the oily mess seen at the exhaust ports of the pop-off
valve, the glycerin/alcohol step is a good idea!
FYI I've uploaded a lot of our collected information about Yak aircraft
(manuals,pictures,diagrams) here:
https://drive.google.com/open?id=0B_E0KXhypQtgejFDendsZmZZaEk
Feel free to peruse and if you have a good addition to make, please send it
on over.
Cheers,
Cliff
On Wed, Sep 2, 2015 at 3:07 PM, Jan Mevis <jan.mevis@informavia.be> wrote:
>
> Thanks a lot Rob! This is impressive! I'll read these documents carefully
.
>
> I was told years ago that the Soviets stopped making this fluid in the
> eighties.
> The glycerine/ethanol is an "ersatz" but I doubt it that the Soviet
> mechanics would have used it without any instructions from above.
>
> Anyway, as you state it very clearly, it's every Yak drivers personal
> responsibility, and I absolutely concur.
> So I stick with what the Lithuanians and the Russians do, in the past and
> today. Until I'm convinced that the PMX-200 is a better product.
>
> And also I have the gear thoroughly checked each year.
>
> BR,
>
> Jan
>
> On 02/09/15 17:26, "Rob Rowe" <owner-yak-list-server@matronics.com on
> behalf of yak-list@robrowe.plus.com> wrote:
>
> >
> >I've been researching YAK pneumatic lubricants over some years and with
> >recent posts on this topic (and some recent progress) I thought I'd shar
e
> >my thoughts for your consideration.
> >
> >1 - Nowhere in the YAK (-52) maintenance manual does it refer to using
> >alcohol/glycerine to lubricate the pneumatic system. The only reference
> >you'll find for this concoction is for drying spark plugs after they've
> >been cleaned. Glycerine is a viscous humectant (a substance that retains
> >moisture) that is only soluble in alcohol or water, hence to get it into
> >the system alcohol has to be added to thin it out. Once introduced at
> >best it will absorb some moisture, but then all of this mix needs to be
> >blown out as soon as possible. Otherwise the alcohol quickly evaporates
> >leaving the viscous Glycerine residue and moisture in the horizontal pip
e
> >runs (typically). This then tends to trap more moisture in these runs
> >causing the most common long term failure mode of internal pin hole
> >corrosion.
> >
> >2 =C3=A2=82=AC=9C So what is the correct lubricant then? The ma
intenance manual
> >states Fluid 132-25 should be used to lubricate the pneumatic system. Bu
t
> >from what I can ascertain Fluid 132-25 went out of production sometime i
n
> >the 1980=C3=A2=82=AC=84=A2s. Given the small quantities needed you
could lubricate
> >pretty well every -52 built with a single 200 litre (45 US gallon) drum
> >per annum =C3=A2=82=AC=C2 so commercially unviable would be my gue
ss as to its
> >demise. Therefore alcohol / glycerine were probably used as a substitute
> >as it was readily to hand for plug maintenance. I=C3=A2=82=AC=84
=A2d also speculate
> >that with DOSAAF utilisation aircraft would be completely stripped down
> >every 5 years, so any problem with pipe corrosion probably wouldn=C3=A2
=82=AC=84=A2t
> >have time to manifest.
> >
> >3 =C3=A2=82=AC=9C To compound this issue the build-up of glycer
ine over time in the
> >pipe runs (which seems to harden - reaction with compressor acidic oil /
> >carbon?) also reduces the air flow and slows the gear operational times.
> >This has led to a number of aircraft having their air flow restrictors
> >removed from the (rear) gear selector connections to help bring
> >extension/retraction times back within specification. While this works i
t
> >may lead to a more insidious problem of higher engagement speeds with th
e
> >gear up-locks at the end of the actuator=C3=A2=82=AC=84=A2s travel
. This energy then
> >gets absorbed by mounting plates inside the wing that may create cracks
> >in them (the subject of a YDB document in 2009 requiring borescope
> >inspection). At first this was thought to be just related to shock loads
> >from gear-up incident aircraft, but has been found to be more widespread
> >across the fleet here in the UK. Giving more credibility to it being a
> >consequence of gear engagement speed.
> >
> >4 =C3=A2=82=AC=9C Addressing this issue in 2010 I tried to sour
ce Fluid 132-25, but
> >while a few East European companies claim they can produce it they never
> >seem to have any stock or require vast minimum order quantities to be
> >made. Finally through the personal contacts of a UK based Russian
> >engineer a chemical company in the Ukraine agreed to make a few litres i
n
> >their labs, which has been used on some YAKs here in the UK (including
> >mine) for the last few years. With the current =C3=A2=82=AC=CB=9Cdiff
iculties=C3=A2=82=AC=84=A2 in the
> >Ukraine it=C3=A2=82=AC=84=A2s unlikely to be repeatable source. Th
e results on my -52
> >have been positive, the gear cycle times noticeably decreased through
> >improved lubrication to the extent that the air flow restrictors could b
e
> >re-installed. Annual monitoring of the up-lock related internal cracks
> >have shown no further increase. Better still the UK CAA allows its use,
> >as an originally specified lubricant, without further approval.
> >
> >5 =C3=A2=82=AC=9C So what is Fluid 132-25? The Russian GOST 109
57-74 specification
> >describes it as an organo-silicon, and on closer examination it=C3=A2
=82=AC=84=A2s a
> >Polyethylsiloxane (PES), the =C3=A2=82=AC=CB=9Cethyl=C3=A2=82=AC
=84=A2 bit gives good low temperature
> >viscosity pour characteristics (-70=C3=82=C2=B0C). Essentially a silicon
e fluid
> >that=C3=A2=82=AC=CB=9Cs a moisture displacement agent and lubricant.
But PES products
> >are niche and difficult to source, not too surprisingly given the above
> >history. However having done some further research into this there is a
> >Dow Corning product that might be a suitable alternative. While it=C3=A2
=82=AC=84=A2s a
> >Polydimethylsiloxane (PDMS) the low temperature pour characteristics
> >(-65=C3=82=C2=B0C) are very nearly as good and it=C3=A2=82=AC=84
=A2s also available within the
> >lower viscosity range of the Fluid 132-25 spec (190-290cSt). Having
> >readily sourced some commercially in the UK in a 1 litre quantity I=C3
=A2=82=AC=84=A2ve
> >saturated some old pneumatic seals in this PDMS silicone fluid for some
6
> >months now with no adverse effects on the seal=C3=A2=82=AC=84=A2s
apparent inte!
> > grity. There has been a seal mass reduction during this time of 3-4%,
> >although this may be due to contaminant leaching from the old seals.
> >I=C3=A2=82=AC=84=A2m now at the stage of approaching the UK CAA fo
r a minor modification
> >approval for use on UK registered YAKs.
> >
> >AS SUCH I HAVE TO RAISE A WARNING THAT I TAKE NO RESPONSIBILTY WHATSOEVE
R
> >FOR ANY ADVERSE EFFECTS ON YOUR AIRCRAFT AND IF YOU CHOOSE TO USE IT THE
N
> >IT=C3=A2=82=AC=84=A2S COMPLETELY AT YOUR OWN VOLITION AND RISK.
> >
> >The product is Dow Corning Xiameter PMX-200 Silicone Fluid (200cSt) and
> >is available in a variety of viscosities. The 200cSt viscosity is the
> >only one closely meeting the Fluid 132-25 specification.
> >
> >Note - =C3=A2=82=AC=CB=9CPMX-200=C3=A2=82=AC=84=A2 is a brand n
ame not a viscosity rating; hence
> >PMX-200 (200cSt) is the specific viscosity required of this product.
> >
> >I=C3=A2=82=AC=84=A2ve posted PDF=C3=A2=82=AC=84=A2s of the R
ussian GOST 10957-74 (Cyrillic) and Dow
> >Corning PMX-200 specifications for reference.
> >
> >Hope this is of some use to the YAK community.
> >
> >Brgds, Rob R.
> >
> >
> >
> >
> >Read this topic online here:
> >
> >http://forums.matronics.com/viewtopic.php?p=446686#446686
> >
> >
> >
> >
> >Attachments:
> >
> >http://forums.matronics.com//files/tds_pmx200_1000cs_602.pdf
> >http://forums.matronics.com//files/gost_10957_74_645.pdf
> >
> >
> >
> >
> >
> >
> >
>
>
===========
===========
===========
===========
>
>
--
Clifford Coy
Border Air Ltd.
C-Parts Inc.
629 Airport Rd.
Swanton, VT 05488
802-868-2822 TEL
802-868-4465 FAX
Skype: Cliff.Coy
Message 2
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| Subject: | Re: YAK Pneumatic Lubricant (long post) |
Thanks Cliff! Awesome!
Jan
From: <owner-yak-list-server@matronics.com> on behalf of Cliff Coy
<cliff.coy@gmail.com>
Subject: Re: Yak-List: YAK Pneumatic Lubricant (long post)
Don't know how or why I received this email thread but...
We've been lubricating actuators, uplocks, and valves for something
like....20 years with Royco 43 Pneumatic system grease with excellent
results.
Royco only sells No.43 in 6.5# cans but commercially available greases
meeting the MIL-G-4343 Pneumatic System Grease specification are sold under
the names JetLube No.33 or Molycote 55M.
The glycerin/alcohol mixture was never meant as a lubricant--merely the
final drying step after the air/water separator and filter assemblies befor
e
the pop-off valve.
As is evidenced by the oily mess seen at the exhaust ports of the pop-off
valve, the glycerin/alcohol step is a good idea!
FYI I've uploaded a lot of our collected information about Yak aircraft
(manuals,pictures,diagrams) here:
https://drive.google.com/open?id=0B_E0KXhypQtgejFDendsZmZZaEk
<https://drive.google.com/open?id=0B_E0KXhypQtgejFDendsZmZZaEk>
Feel free to peruse and if you have a good addition to make, please send it
on over.
Cheers,
Cliff
On Wed, Sep 2, 2015 at 3:07 PM, Jan Mevis <jan.mevis@informavia.be> wrote:
>
> Thanks a lot Rob! This is impressive! I'll read these documents carefully
.
>
> I was told years ago that the Soviets stopped making this fluid in the
> eighties.
> The glycerine/ethanol is an "ersatz" but I doubt it that the Soviet
> mechanics would have used it without any instructions from above.
>
> Anyway, as you state it very clearly, it's every Yak drivers personal
> responsibility, and I absolutely concur.
> So I stick with what the Lithuanians and the Russians do, in the past and
> today. Until I'm convinced that the PMX-200 is a better product.
>
> And also I have the gear thoroughly checked each year.
>
> BR,
>
> Jan
>
> On 02/09/15 17:26, "Rob Rowe" <owner-yak-list-server@matronics.com on
> behalf of yak-list@robrowe.plus.com> wrote:
>
>> >
>> >I've been researching YAK pneumatic lubricants over some years and with
>> >recent posts on this topic (and some recent progress) I thought I'd sha
re
>> >my thoughts for your consideration.
>> >
>> >1 - Nowhere in the YAK (-52) maintenance manual does it refer to using
>> >alcohol/glycerine to lubricate the pneumatic system. The only reference
>> >you'll find for this concoction is for drying spark plugs after they've
>> >been cleaned. Glycerine is a viscous humectant (a substance that retain
s
>> >moisture) that is only soluble in alcohol or water, hence to get it int
o
>> >the system alcohol has to be added to thin it out. Once introduced at
>> >best it will absorb some moisture, but then all of this mix needs to be
>> >blown out as soon as possible. Otherwise the alcohol quickly evaporates
>> >leaving the viscous Glycerine residue and moisture in the horizontal pi
pe
>> >runs (typically). This then tends to trap more moisture in these runs
>> >causing the most common long term failure mode of internal pin hole
>> >corrosion.
>> >
>> >2 =C3=A2=82=AC=9C So what is the correct lubricant then? The maintenance manua
l
>> >states Fluid 132-25 should be used to lubricate the pneumatic system. B
ut
>> >from what I can ascertain Fluid 132-25 went out of production sometime
in
>> >the 1980=C3=A2=82=AC=84=A2s. Given the small quantities needed you could lubricat
e
>> >pretty well every -52 built with a single 200 litre (45 US gallon) drum
>> >per annum =C3=A2=82=AC=C2 so commercially unviable would be my guess as to
its
>> >demise. Therefore alcohol / glycerine were probably used as a substitut
e
>> >as it was readily to hand for plug maintenance. I=C3=A2=82=AC=84=A2d also
specul
ate
>> >that with DOSAAF utilisation aircraft would be completely stripped down
>> >every 5 years, so any problem with pipe corrosion probably wouldn=C3=A2=82=AC
=84=A2t
>> >have time to manifest.
>> >
>> >3 =C3=A2=82=AC=9C To compound this issue the build-up of glycerine over time
i
n the
>> >pipe runs (which seems to harden - reaction with compressor acidic oil
/
>> >carbon?) also reduces the air flow and slows the gear operational times
.
>> >This has led to a number of aircraft having their air flow restrictors
>> >removed from the (rear) gear selector connections to help bring
>> >extension/retraction times back within specification. While this works
it
>> >may lead to a more insidious problem of higher engagement speeds with t
he
>> >gear up-locks at the end of the actuator=C3=A2=82=AC=84=A2s travel. This energy
t
hen
>> >gets absorbed by mounting plates inside the wing that may create cracks
>> >in them (the subject of a YDB document in 2009 requiring borescope
>> >inspection). At first this was thought to be just related to shock load
s
>> >from gear-up incident aircraft, but has been found to be more widesprea
d
>> >across the fleet here in the UK. Giving more credibility to it being a
>> >consequence of gear engagement speed.
>> >
>> >4 =C3=A2=82=AC=9C Addressing this issue in 2010 I tried to source Fluid 132-25
, but
>> >while a few East European companies claim they can produce it they neve
r
>> >seem to have any stock or require vast minimum order quantities to be
>> >made. Finally through the personal contacts of a UK based Russian
>> >engineer a chemical company in the Ukraine agreed to make a few litres
in
>> >their labs, which has been used on some YAKs here in the UK (including
>> >mine) for the last few years. With the current =C3=A2=82=AC=CB=9Cdifficulties=C3=A2=82=AC
=84=A2 in the
>> >Ukraine it=C3=A2=82=AC=84=A2s unlikely to be repeatable source. The results
on my
-52
>> >have been positive, the gear cycle times noticeably decreased through
>> >improved lubrication to the extent that the air flow restrictors could
be
>> >re-installed. Annual monitoring of the up-lock related internal cracks
>> >have shown no further increase. Better still the UK CAA allows its use,
>> >as an originally specified lubricant, without further approval.
>> >
>> >5 =C3=A2=82=AC=9C So what is Fluid 132-25? The Russian GOST 10957-74 specifica
tion
>> >describes it as an organo-silicon, and on closer examination it=C3=A2=82=AC=84=A2
s a
>> >Polyethylsiloxane (PES), the =C3=A2=82=AC=CB=9Cethyl=C3=A2=82=AC=84=A2 bit
gives good low te
mperature
>> >viscosity pour characteristics (-70=C3=82=C2=B0C). Essentially a silicone fluid
>> >that=C3=A2=82=AC=CB=9Cs a moisture displacement agent and lubricant. But PES
produ
cts
>> >are niche and difficult to source, not too surprisingly given the above
>> >history. However having done some further research into this there is a
>> >Dow Corning product that might be a suitable alternative. While it=C3=A2=82=AC
=84=A2s a
>> >Polydimethylsiloxane (PDMS) the low temperature pour characteristics
>> >(-65=C3=82=C2=B0C) are very nearly as good and it=C3=A2=82=AC=84=A2s also available
withi
n the
>> >lower viscosity range of the Fluid 132-25 spec (190-290cSt). Having
>> >readily sourced some commercially in the UK in a 1 litre quantity I=C3=A2=82
=AC=84=A2ve
>> >saturated some old pneumatic seals in this PDMS silicone fluid for some
6
>> >months now with no adverse effects on the seal=C3=A2=82=AC=84=A2s apparent
inte!
>> > grity. There has been a seal mass reduction during this time of 3-4%,
>> >although this may be due to contaminant leaching from the old seals.
>> >I=C3=A2=82=AC=84=A2m now at the stage of approaching the UK CAA for a minor
modif
ication
>> >approval for use on UK registered YAKs.
>> >
>> >AS SUCH I HAVE TO RAISE A WARNING THAT I TAKE NO RESPONSIBILTY WHATSOEV
ER
>> >FOR ANY ADVERSE EFFECTS ON YOUR AIRCRAFT AND IF YOU CHOOSE TO USE IT TH
EN
>> >IT=C3=A2=82=AC=84=A2S COMPLETELY AT YOUR OWN VOLITION AND RISK.
>> >
>> >The product is Dow Corning Xiameter PMX-200 Silicone Fluid (200cSt) and
>> >is available in a variety of viscosities. The 200cSt viscosity is the
>> >only one closely meeting the Fluid 132-25 specification.
>> >
>> >Note - =C3=A2=82=AC=CB=9CPMX-200=C3=A2=82=AC=84=A2 is a brand name not a viscosity
rating; h
ence
>> >PMX-200 (200cSt) is the specific viscosity required of this product.
>> >
>> >I=C3=A2=82=AC=84=A2ve posted PDF=C3=A2=82=AC=84=A2s of the Russian GOST 10957-74
(Cyrillic)
and Dow
>> >Corning PMX-200 specifications for reference.
>> >
>> >Hope this is of some use to the YAK community.
>> >
>> >Brgds, Rob R.
>> >
>> >
>> >
>> >
>> >Read this topic online here:
>> >
>> >http://forums.matronics.com/viewtopic.php?p=446686#446686
>> >
>> >
>> >
>> >
>> >Attachments:
>> >
>> >http://forums.matronics.com//files/tds_pmx200_1000cs_602.pdf
>> >http://forums.matronics.com//files/gost_10957_74_645.pdf
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>
>
>
>
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>
--
Clifford Coy
Border Air Ltd.
C-Parts Inc.
629 Airport Rd.
Swanton, VT 05488
802-868-2822 TEL
802-868-4465 FAX
Skype: Cliff.Coy
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