Today's Message Index:
----------------------
1. 04:41 AM - Rehab RV - Engine mount and Nose gear (cliff dominey)
2. 05:07 AM - Re: Rehab RV - Engine mount and Nose gear (Denis Walsh)
3. 06:20 AM - Re: Rehab RV - Engine mount and Nose gear (Charles Kuss)
4. 07:41 AM - Re: Rehab RV - Engine mount and Nose gear (David Burton)
5. 11:32 AM - Re: Rehab RV - Engine mount and Nose gear (Charlie England)
6. 12:35 PM - Re: Rehab RV - Engine mount and Nose gear (Greg Young)
7. 01:00 PM - Re: Rehab RV - Engine mount and Nose gear (Linn Walters)
8. 01:00 PM - Re: Rehab RV - Engine mount and Nose gear (Linn Walters)
9. 05:33 PM - UHMW Tape - possible source of concern (vanremog@aol.com)
10. 06:19 PM - Re: UHMW Tape - possible source of concern (HCRV6@comcast.net)
11. 06:34 PM - Re: UHMW Tape - possible source of concern (Kyle Boatright)
12. 08:17 PM - Re: Rehab RV - Engine mount and Nose gear (Kelly McMullen)
13. 09:05 PM - Re: UHMW Tape - possible source of concern (Terry Watson)
14. 09:59 PM - Re: UHMW Tape - possible source of concern (Al & Gail Herron)
Message 1
INDEX | Back to Main INDEX |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Rehab RV - Engine mount and Nose gear |
I am trying to restore a damaged RV8A. Nose gear leg is stuck in the engin
e mount=2C and I am thinking about heat application while it is in the hydr
aulic press.
>From my quick research online=2C the steel strength should not be affected
so long as it is not heated beyond 40% of the melting point=2C or about 100
0 deg F. If I keep an IR thermometer on it during the attempt=2C and keep
the temp below 800=2C I figure I am probably ok. But for the purpose of he
at expansion=2C maybe about 500 would be enough.
Any metalurists on the list? Funny things happen during that cooling down
period.
C Dominey
csdjbtexas@live.com
Message 2
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Rehab RV - Engine mount and Nose gear |
I am not a metalologist and haven't played one.
But I have talked to Harmon Lange, the builder of those legs. Go to
his web site or call him on the phone. he has all the answers, and
can sell you a new leg or straighten your old one, if feasible.
http://www.langair.com/
On Oct 21, 2011, at 5:38 , cliff dominey wrote:
> I am trying to restore a damaged RV8A. Nose gear leg is stuck in
> the engine mount, and I am thinking about heat application while it
> is in the hydraulic press.
> From my quick research online, the steel strength should not be
> affected so long as it is not heated beyond 40% of the melting
> point, or about 1000 deg F. If I keep an IR thermometer on it
> during the attempt, and keep the temp below 800, I figure I am
> probably ok. But for the purpose of heat expansion, maybe about 500
> would be enough.
> Any metalurists on the list? Funny things happen during that
> cooling down period.
> C Dominey
> csdjbtexas@live.com
>
>
Message 3
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Rehab RV - Engine mount and Nose gear |
Cliff
-The gear legs are heat treated. Re-heating will destroy that. Best to or
der new parts.
Charlie
--- On Fri, 10/21/11, cliff dominey <csdjbtexas@live.com> wrote:
From: cliff dominey <csdjbtexas@live.com>
Subject: RV-List: Rehab RV - Engine mount and Nose gear
=0A=0A=0A=0AI am trying to restore a damaged RV8A.- Nose gear leg is stuc
k in the engine mount, and I am thinking about heat application while it is
in the hydraulic press.=0AFrom my quick research online, the steel strengt
h should not be affected so long as it is not heated beyond 40% of the melt
ing point, or about 1000 deg F.- If I keep an IR thermometer on it during
the attempt, and keep the temp below 800, I figure I am probably ok.- Bu
t for the purpose of heat expansion, maybe about 500 would be enough.=0AAny
metalurists on the list?- Funny things happen during that cooling down p
eriod.=0AC Dominey=0Acsdjbtexas@live.com =0A=0A
Message 4
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Rehab RV - Engine mount and Nose gear |
This is a much more complex problem then just the melting point of
steel. The atoms in steels have been specifically arranged during
manufacturing to produce the desired mechanical properties. There are
many complex structures in the steel at an atomic level. You can
influence these properties by applying both heat or cold. The sinking
of the Titanic is an example of this. The atomic structure of the steel
(and its strength) was altered by the cold water temperatures causing
the rivets to fail at a fraction of their room temperature strength.
This was an unknown property at the time. While this property is
transitory and changes with temperature, the altering of the atomic
structure of the material by heat, impact or deformation is permanent
until altered by the application of these inputs again.
Where this can bite you badly is by inadvertently heating a localized
area of a larger piece. The entire part doesn't get very hot, but some
small part of it does. The large part can act as a heat sink causing
rapid cooling of the small area that has been heated. This is exactly
like quenching a knife blade to make it hard enough to allow it to hold
an edge. This hard and brittle localized area in an larger area of
softer material will cause stresses to concentrate there and cause
cracking.
This was identified as a huge problem with untrained people welding
hitches onto vehicles which subsequently failed at weld/frame junction
(not the weld itself) that it was outlawed. You may have noticed that
aftermarket hitches are all bolted on now. Only a certified welder is
allowed to weld a hitch on and most insurance companies are not OK with
allowing even them to do this.
You can probably carefully warm the engine mount enough to help loosen
the gear leg without danger. You probably shouldn't apply heat to the
leg.
Striking the parts can help to loosen the bond between them. You must
be careful to use a soft non-ferrous hammer or drift so you don't damage
the parts.
The bond that is preventing you from separating the two parts is
frequently caused by corrosion products, so using a penetrating oil can
be useful. Use one safe for steel. Use a lot, over a long period of
time. It make take quite a while for the oil to wick through the entire
joint.
I am suspicious that in your case the engine mount has been deformed by
the impact that caused the damage to the aircraft and this is preventing
the gear leg from being removed. The impact to the engine mount may
have done other damage to it and having the mount inspected might be
wise.
I'm sure you are like me and want to do this yourself. I suspect that
if you get this problem to the engine mount manufacturer they can solve
it for you. It might involve removing a section of the mount and
replacing it. They can do this without damaging the gear leg. Finding
out at this point that the mount is bent or cracked would be preferable
to having problems later...
Good luck,
David
(Former material scientist and accident investigator)
Message 5
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Rehab RV - Engine mount and Nose gear |
On 10/21/2011 06:38 AM, cliff dominey wrote:
> I am trying to restore a damaged RV8A. Nose gear leg is stuck in the
> engine mount, and I am thinking about heat application while it is in
> the hydraulic press.
> From my quick research online, the steel strength should not be
> affected so long as it is not heated beyond 40% of the melting point,
> or about 1000 deg F. If I keep an IR thermometer on it during the
> attempt, and keep the temp below 800, I figure I am probably ok. But
> for the purpose of heat expansion, maybe about 500 would be enough.
> Any metalurists on the list? Funny things happen during that cooling
> down period.
> C Dominey
> csdjbtexas@live.com <mailto:csdjbtexas@live.com>
>
If it's rust that's causing your problem, try googling 'acetone and
automatic transmission fluid'.
Charlie
(It works for me; I now keep a pump-oil can handy when working on old
equipment.)
Message 6
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Rehab RV - Engine mount and Nose gear |
Since you have the mount off try using your rivet gun with a flush set to
tap on the end of the gear leg. It doesn't have to be real strong - about
the same as for AN3 rivets. It works like magic to install and remove the
close tolerance spar bolts where brute force fails. It's a good idea to prep
it with penetrating oil like Kroil. It's excellent but hard to find.
Greg Young
From: owner-rv-list-server@matronics.com
[mailto:owner-rv-list-server@matronics.com] On Behalf Of Charlie England
Sent: Friday, October 21, 2011 12:54 PM
Subject: Re: RV-List: Rehab RV - Engine mount and Nose gear
On 10/21/2011 06:38 AM, cliff dominey wrote:
I am trying to restore a damaged RV8A. Nose gear leg is stuck in the engine
mount, and I am thinking about heat application while it is in the hydraulic
press.
>From my quick research online, the steel strength should not be affected so
long as it is not heated beyond 40% of the melting point, or about 1000 deg
F. If I keep an IR thermometer on it during the attempt, and keep the temp
below 800, I figure I am probably ok. But for the purpose of heat
expansion, maybe about 500 would be enough.
Any metalurists on the list? Funny things happen during that cooling down
period.
C Dominey
csdjbtexas@live.com
If it's rust that's causing your problem, try googling 'acetone and
automatic transmission fluid'.
Charlie
(It works for me; I now keep a pump-oil can handy when working on old
equipment.)
Message 7
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Rehab RV - Engine mount and Nose gear |
Get Kroil from Kano Labs. Google 'kroil' for a special deal. And don't
blow it off for price. The stuff is worth it.
Linn
On 10/21/2011 3:20 PM, Greg Young wrote:
>
> Since you have the mount off try using your rivet gun with a flush set
> to tap on the end of the gear leg. It doesn't have to be real strong
> -- about the same as for AN3 rivets. It works like magic to install
> and remove the close tolerance spar bolts where brute force fails.
> It's a good idea to prep it with penetrating oil like Kroil. It's
> excellent but hard to find.
>
> Greg Young
>
> *From:*owner-rv-list-server@matronics.com
> [mailto:owner-rv-list-server@matronics.com] *On Behalf Of *Charlie England
> *Sent:* Friday, October 21, 2011 12:54 PM
> *To:* rv-list@matronics.com
> *Subject:* Re: RV-List: Rehab RV - Engine mount and Nose gear
>
> On 10/21/2011 06:38 AM, cliff dominey wrote:
>
> I am trying to restore a damaged RV8A. Nose gear leg is stuck in the
> engine mount, and I am thinking about heat application while it is in
> the hydraulic press.
>
> From my quick research online, the steel strength should not be
> affected so long as it is not heated beyond 40% of the melting point,
> or about 1000 deg F. If I keep an IR thermometer on it during the
> attempt, and keep the temp below 800, I figure I am probably ok. But
> for the purpose of heat expansion, maybe about 500 would be enough.
>
> Any metalurists on the list? Funny things happen during that cooling
> down period.
>
> C Dominey
>
> csdjbtexas@live.com <mailto:csdjbtexas@live.com>
>
> If it's rust that's causing your problem, try googling 'acetone and
> automatic transmission fluid'.
>
> Charlie
> (It works for me; I now keep a pump-oil can handy when working on old
> equipment.)
>
> * *
> * *
> *
>
>
> *
Message 8
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Rehab RV - Engine mount and Nose gear |
Get Kroil from Kano Labs. Google 'kroil' for a special deal. And don't
blow it off for price. The stuff is worth it.
Linn
On 10/21/2011 3:20 PM, Greg Young wrote:
>
> Since you have the mount off try using your rivet gun with a flush set
> to tap on the end of the gear leg. It doesn't have to be real strong
> -- about the same as for AN3 rivets. It works like magic to install
> and remove the close tolerance spar bolts where brute force fails.
> It's a good idea to prep it with penetrating oil like Kroil. It's
> excellent but hard to find.
>
> Greg Young
>
> *From:*owner-rv-list-server@matronics.com
> [mailto:owner-rv-list-server@matronics.com] *On Behalf Of *Charlie England
> *Sent:* Friday, October 21, 2011 12:54 PM
> *To:* rv-list@matronics.com
> *Subject:* Re: RV-List: Rehab RV - Engine mount and Nose gear
>
> On 10/21/2011 06:38 AM, cliff dominey wrote:
>
> I am trying to restore a damaged RV8A. Nose gear leg is stuck in the
> engine mount, and I am thinking about heat application while it is in
> the hydraulic press.
>
> From my quick research online, the steel strength should not be
> affected so long as it is not heated beyond 40% of the melting point,
> or about 1000 deg F. If I keep an IR thermometer on it during the
> attempt, and keep the temp below 800, I figure I am probably ok. But
> for the purpose of heat expansion, maybe about 500 would be enough.
>
> Any metalurists on the list? Funny things happen during that cooling
> down period.
>
> C Dominey
>
> csdjbtexas@live.com <mailto:csdjbtexas@live.com>
>
> If it's rust that's causing your problem, try googling 'acetone and
> automatic transmission fluid'.
>
> Charlie
> (It works for me; I now keep a pump-oil can handy when working on old
> equipment.)
>
> * *
> * *
> *
>
>
> *
Message 9
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | UHMW Tape - possible source of concern |
As one of the earlier adopters of the 3" wide UHMW tape as a protective str
ip (as opposed to the older Stainless Steel tape) when placed on the curved
leading edge of the flaps, I wanted to share a possible cause of concern w
ith all of you. Today I was working on my car and needed a wide piece of ta
pe for an application. I immediately thought of the roll of UHMW left from
my building days back in the late '90s. In the process of unreeling a lengt
h of this tape for use, I found that it broke on the liner like glass. I we
nt thru the entire roll and it has all deteriorated to the point of unusabi
lity. The roll has been stored in a closed box for the past 14 yrs, so it n
ever has seen UV exposure. It breaks up in a zillion shards when flexed and
so it all ended up going into the waste can. Mine was bought from US Plast
ics but I would assume that all UHMW used in thin sections may have similar
characteristics with age.
Since the flap use application on the plane is fairly stable, I think it ma
y still be okay if left undisturbed. But if it ever gets to flaking off, I
would assume that it could potentially jam the mechanism upon retraction, s
ince the clearance to the wing skin is tight and the sharp edge it presents
could catch in the break. I would encourage you all to be aware of this po
ssibility and act accordingly.
If it ever starts coming off in pieces, I'll do the tedious complete remova
l process from both flaps and go back to the old tried and true Stainless S
teel tape, since it doesn't degrade like this. Either that or I'll place an
other longer lasting strip material on the underside of the top skin where
the flap curved edge wipes.
YMMV
-GV RV-6A flying 985hrs
Message 10
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: UHMW Tape - possible source of concern |
Good tip GV. I have noticed that the UHMW on my flaps, now seven years old, has
started to yellow. I will keep a close watch on this.
Harry Crosby
RV-6 N16CX, 885 hours
----- Original Message -----
From: vanremog@aol.com
Sent: Friday, October 21, 2011 5:21:27 PM
Subject: RV-List: UHMW Tape - possible source of concern
As one of the earlier adopters of the 3" wide UHMW tape as a protective strip (as
opposed to the older Stainless Steel tape) when placed on the curved leading
edge of the flaps, I wanted to share a possible cause of concern with all of
you. Today I was working on my car and needed a wide piece of tape for an application.
I immediately thought of the roll of UHMW left from my building days
back in the late '90s. In the process of unreeling a length of this tape for
use, I found that it broke on the liner like glass. I went thru the entire roll
and it has all deteriorated to the point of unusability. The roll has been stored
in a closed box for the past 14 yrs, so it never has seen UV exposure. It
breaks up in a zillion shards when flexed and so it all ended up going into
the waste can. Mine was bought from US Plastics but I would assume that all UHMW
used in thin sections may have similar characteristics with age.
Since the flap use application on the plane is fairly stable, I think it may still
be okay if left undisturbed. But if it ever gets to flaking off, I would assume
that it could potentially jam the mechanism upon retraction, since the clearance
to the wing skin is tight and the sharp edge it presents could catch
in the break. I would encourage you all to be aware of this possibility and act
accordingly.
If it ever starts coming off in pieces, I'll do the tedious complete removal process
from both flaps and go back to the old tried and true Stainless Steel tape,
since it doesn't degrade like this. Either that or I'll place another longer
lasting strip material on the underside of the top skin where the flap curved
edge wipes.
YMMV
Message 11
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: UHMW Tape - possible source of concern |
I replaced the UHMW flap tape on my airplane a month or so ago. The
wear layer had become brittle and had begun to delaminate from the other
(2?) layers. Removing the wear layer was easy, but the other two layers
were a bear until I checked with my friends at a local auto paint store.
They pointed me towards a vinyl striping removal wheel like this:
http://www.amazon.com/gp/product/B0020HQRQC/ref=pd_lpo_k2_dp_sr_2?pf_rd
_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t 1&pf_rd_i=B00063V
T0G&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0SHHTFTYBF2GY0RN4ZXH
Basically a 3" diameter eraser that uses friction to heat, then shear
off the remaining layers of the tape. One wheel was just enough to do
the job (the wheel wears down during the process).
With this tool, it took 30 minutes to clean off each flap. I used one
of the clear films (like for rock protection on cars) as a replacement
for the UHMW. It applied easily, but it'll be a few years before I can
report on how well it holds up.
Kyle Boatright
2001 RV-6
----- Original Message -----
From: vanremog@aol.com
To: rv-list@matronics.com
Sent: Friday, October 21, 2011 8:21 Subject: RV-List: UHMW Tape -
possible source of concern
As one of the earlier adopters of the 3" wide UHMW tape as a
protective strip (as opposed to the older Stainless Steel tape) when
placed on the curved leading edge of the flaps, I wanted to share a
possible cause of concern with all of you. Today I was working on my car
and needed a wide piece of tape for an application. I immediately
thought of the roll of UHMW left from my building days back in the late
'90s. In the process of unreeling a length of this tape for use, I found
that it broke on the liner like glass. I went thru the entire roll and
it has all deteriorated to the point of unusability. The roll has been
stored in a closed box for the past 14 yrs, so it never has seen UV
exposure. It breaks up in a zillion shards when flexed and so it all
ended up going into the waste can. Mine was bought from US Plastics but
I would assume that all UHMW used in thin sections may have similar
characteristics with age.
Since the flap use application on the plane is fairly stable, I think
it may still be okay if left undisturbed. But if it ever gets to flaking
off, I would assume that it could potentially jam the mechanism upon
retraction, since the clearance to the wing skin is tight and the sharp
edge it presents could catch in the break. I would encourage you all to
be aware of this possibility and act accordingly.
If it ever starts coming off in pieces, I'll do the tedious complete
removal process from both flaps and go back to the old tried and true
Stainless Steel tape, since it doesn't degrade like this. Either that or
I'll place another longer lasting strip material on the underside of the
top skin where the flap curved edge wipes.
YMMV
-GV RV-6A flying 985hrs
Message 12
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Rehab RV - Engine mount and Nose gear |
The previously mentioned acetone with ATF works better in penetrating
and freeing parts than any commercial product, almost by a factor of 2.
On 10/21/2011 12:20 PM, Greg Young wrote:
>
> Since you have the mount off try using your rivet gun with a flush set
> to tap on the end of the gear leg. It doesnt have to be real strong
> about the same as for AN3 rivets. It works like magic to install and
> remove the close tolerance spar bolts where brute force fails. Its a
> good idea to prep it with penetrating oil like Kroil. Its excellent
> but hard to find.
>
> Greg Young
>
> *From:*owner-rv-list-server@matronics.com
> [mailto:owner-rv-list-server@matronics.com] *On Behalf Of *Charlie England
> *Sent:* Friday, October 21, 2011 12:54 PM
> *To:* rv-list@matronics.com
> *Subject:* Re: RV-List: Rehab RV - Engine mount and Nose gear
>
> On 10/21/2011 06:38 AM, cliff dominey wrote:
>
> I am trying to restore a damaged RV8A. Nose gear leg is stuck in the
> engine mount, and I am thinking about heat application while it is in
> the hydraulic press.
>
> From my quick research online, the steel strength should not be
> affected so long as it is not heated beyond 40% of the melting point,
> or about 1000 deg F. If I keep an IR thermometer on it during the
> attempt, and keep the temp below 800, I figure I am probably ok. But
> for the purpose of heat expansion, maybe about 500 would be enough.
>
> Any metalurists on the list? Funny things happen during that cooling
> down period.
>
> C Dominey
>
> csdjbtexas@live.com <mailto:csdjbtexas@live.com>
>
> If it's rust that's causing your problem, try googling 'acetone and
> automatic transmission fluid'.
>
> Charlie
> (It works for me; I now keep a pump-oil can handy when working on old
> equipment.)
>
> * *
> * *
> *
>
>
> *
Message 13
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | UHMW Tape - possible source of concern |
A few years back, I used the tape that I had bought for the wear protection
on my flaps and put it on the top edge of the tailgate of my pickup to
protect the paint from being rubbed off by the bottom edge of the canopy
rear opening window. It actually wasn't very long before it became yellow
and brittle. I decided to use something else on the flaps. Unfortunately, I
never got far enough on my RV-8A to need to find a better tape.
Terry
From: owner-rv-list-server@matronics.com
[mailto:owner-rv-list-server@matronics.com] On Behalf Of vanremog@aol.com
Sent: Friday, October 21, 2011 5:21 PM
Subject: RV-List: UHMW Tape - possible source of concern
As one of the earlier adopters of the 3" wide UHMW tape as a protective
strip (as opposed to the older Stainless Steel tape) when placed on the
curved leading edge of the flaps, I wanted to share a possible cause of
concern with all of you. Today I was working on my car and needed a wide
piece of tape for an application. I immediately thought of the roll of UHMW
left from my building days back in the late '90s. In the process of
unreeling a length of this tape for use, I found that it broke on the liner
like glass. I went thru the entire roll and it has all deteriorated to the
point of unusability. The roll has been stored in a closed box for the past
14 yrs, so it never has seen UV exposure. It breaks up in a zillion shards
when flexed and so it all ended up going into the waste can. Mine was bought
from US Plastics but I would assume that all UHMW used in thin sections may
have similar characteristics with age.
Since the flap use application on the plane is fairly stable, I think it may
still be okay if left undisturbed. But if it ever gets to flaking off, I
would assume that it could potentially jam the mechanism upon retraction,
since the clearance to the wing skin is tight and the sharp edge it presents
could catch in the break. I would encourage you all to be aware of this
possibility and act accordingly.
If it ever starts coming off in pieces, I'll do the tedious complete removal
process from both flaps and go back to the old tried and true Stainless
Steel tape, since it doesn't degrade like this. Either that or I'll place
another longer lasting strip material on the underside of the top skin where
the flap curved edge wipes.
YMMV
-GV RV-6A flying 985hrs
Message 14
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | UHMW Tape - possible source of concern |
My UMHW tape was installed in late 2008/early 2009, probably was ordered
from Vans's no earlier than 2005. I was very disappointed in how poorly it
held up, it is doing exactly as you describe, extensively cracked and in
some places pieces have come off. So far I've just been keeping an eye on
it, although I really should strip it off and replace it with something
better. I'm not too concerned about it jamming the flaps, although it
certainly is a theoretical possibility. For one thing, it's so broken up
that no individual piece would be more than an inch or two wide. I think it
would be more likely to catch the edge of the upper wing skin and just pop
off. Definitely near the top of my squawk list though.
Anyone know of a better brand of UMHW, or another alternative? I did see
mention of stainless steel tape in one response.
Al in Hangtown CA
RV-7A, 175 hrs
From: owner-rv-list-server@matronics.com
[mailto:owner-rv-list-server@matronics.com] On Behalf Of vanremog@aol.com
Sent: Friday, October 21, 2011 5:21 PM
Subject: RV-List: UHMW Tape - possible source of concern
As one of the earlier adopters of the 3" wide UHMW tape as a protective
strip (as opposed to the older Stainless Steel tape) when placed on the
curved leading edge of the flaps, I wanted to share a possible cause of
concern with all of you. Today I was working on my car and needed a wide
piece of tape for an application. I immediately thought of the roll of UHMW
left from my building days back in the late '90s. In the process of
unreeling a length of this tape for use, I found that it broke on the liner
like glass. I went thru the entire roll and it has all deteriorated to the
point of unusability. The roll has been stored in a closed box for the past
14 yrs, so it never has seen UV exposure. It breaks up in a zillion shards
when flexed and so it all ended up going into the waste can. Mine was bought
from US Plastics but I would assume that all UHMW used in thin sections may
have similar characteristics with age.
Since the flap use application on the plane is fairly stable, I think it may
still be okay if left undisturbed. But if it ever gets to flaking off, I
would assume that it could potentially jam the mechanism upon retraction,
since the clearance to the wing skin is tight and the sharp edge it presents
could catch in the break. I would encourage you all to be aware of this
possibility and act accordingly.
If it ever starts coming off in pieces, I'll do the tedious complete removal
process from both flaps and go back to the old tried and true Stainless
Steel tape, since it doesn't degrade like this. Either that or I'll place
another longer lasting strip material on the underside of the top skin where
the flap curved edge wipes.
YMMV
-GV RV-6A flying 985hrs
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|