Help With Leak Test Results

Yup, one of my goals in life is to be able to afford to call 'em and have
them ship me 6 of everything . . .

Seriously, placing an order with them is a problem, 'cause there's always
something you should have included in the order but forgot.

When you order the pinch clamps, don't forget to get a roll of UHMW
polyethylene tape. Great for anti-chafe etc. Their number is 76445A12 for
the 1" wide X .0065" X 18 yds.

bumper
"Papa3" wrote in message
oups.com...
http://www.mcmaster.com

Page 233 for pinch clamps

I think one day I will just buy all of the bits needed to build my own
glider from these guys - it's pretty much the default source for
anything that I can imagine needing.

P3

bumper wrote:
Yup, one of my goals in life is to be able to afford to call 'em and have
them ship me 6 of everything . . .

Seriously, placing an order with them is a problem, 'cause there's always
something you should have included in the order but forgot.

When you order the pinch clamps, don't forget to get a roll of UHMW
polyethylene tape. Great for anti-chafe etc. Their number is 76445A12 for
the 1" wide X .0065" X 18 yds.

bumper
"Papa3" wrote in message
oups.com...

http://www.mcmaster.com

I also recommend getting some of their silicone tubing to connect your
instruments. I started using it when some came with my Cambridge vario a
few years ago. It is softer and more flexible the typical clear (but
often colored) plastic tubing and remains that way instead of hardening
over the years. That makes it easy to put it on the instrument, easy to
remove (just pull - no cutting required), and it doesn't need clamps to
prevent leaks.

Because the glider is plumbed in the usual clear tubing, you need to
transition from that to the silicone with a barbed fitting (straight,
tee, or cross, depending on how many things you want to connect to the
particular line). You could use a clamp on the original plastic line
tubing, but because it is never removed, I haven't had any problems with
leaks there.

It costs a bit more, but you can buy it from McMaster-Carr in short
lengths, so the price is not an issue.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

www.motorglider.org

In message , Eric Greenwell
writes

I also recommend getting some of their silicone tubing to connect your
instruments. I started using it when some came with my Cambridge vario
a few years ago. It is softer and more flexible the typical clear (but
often colored) plastic tubing and remains that way instead of hardening
over the years. That makes it easy to put it on the instrument, easy to
remove (just pull - no cutting required), and it doesn't need clamps to
prevent leaks.

Because the glider is plumbed in the usual clear tubing, you need to
transition from that to the silicone with a barbed fitting (straight,
tee, or cross, depending on how many things you want to connect to the
particular line). You could use a clamp on the original plastic line
tubing, but because it is never removed, I haven't had any problems
with leaks there.

It costs a bit more, but you can buy it from McMaster-Carr in short
lengths, so the price is not an issue.


I would also recommend putting springs over the silicone pipe if there
is any chance of a sharp bend coming up as it can collapse and
effectively seal the tube.

Robin

--
Robin Birch

Robin Birch wrote:
In message , Eric Greenwell
writes


I also recommend getting some of their silicone tubing to connect your
instruments. I started using it when some came with my Cambridge vario
a few years ago. It is softer and more flexible the typical clear (but
often colored) plastic tubing and remains that way instead of
hardening over the years. That makes it easy to put it on the
instrument, easy to remove (just pull - no cutting required), and it
doesn't need clamps to prevent leaks.

Because the glider is plumbed in the usual clear tubing, you need to
transition from that to the silicone with a barbed fitting (straight,
tee, or cross, depending on how many things you want to connect to the
particular line). You could use a clamp on the original plastic line
tubing, but because it is never removed, I haven't had any problems
with leaks there.

It costs a bit more, but you can buy it from McMaster-Carr in short
lengths, so the price is not an issue.


I would also recommend putting springs over the silicone pipe if there
is any chance of a sharp bend coming up as it can collapse and
effectively seal the tube.

That doesn't seem necessary with the tubing I have, unless it is quite
sharp; for example, bending the tubing in a "U" that is 1.5" (measured
at the center of the tubing) across doesn't cause a problem. It has a
maximum temperature rating of 500 F, so cockpit temperatures won't be a
problem! The McMaster-Carr label on the bag it came in is says

Vanguard Products
Size: 3/16" (ID) x 5/16" (OD)
Material: translucent, 50 Duro silicone


Other types might be more prone to collapse, but this one seems quite
resistant.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

www.motorglider.org

In message , Eric Greenwell
writes
Robin Birch wrote:


I would also recommend putting springs over the silicone pipe if
there is any chance of a sharp bend coming up as it can collapse and
effectively seal the tube.

That doesn't seem necessary with the tubing I have, unless it is quite
sharp; for example, bending the tubing in a "U" that is 1.5" (measured
at the center of the tubing) across doesn't cause a problem. It has a
maximum temperature rating of 500 F, so cockpit temperatures won't be a
problem! The McMaster-Carr label on the bag it came in is says

Vanguard Products
Size: 3/16" (ID) x 5/16" (OD)
Material: translucent, 50 Duro silicone


Other types might be more prone to collapse, but this one seems quite
resistant.

Well I know to my cost that the standard silicon tubing you can get in
the UK suffers from this problem. Especially if you don't secure the
pipes in the shapes that you want them to follow.

I've also known them to temporarily compress if something moves behind
the panel in severe turbulence.

Robin

--
Robin Birch

bumper wrote:
Yup, one of my goals in life is to be able to afford to call 'em and have
them ship me 6 of everything . . .

Seriously, placing an order with them is a problem, 'cause there's always
something you should have included in the order but forgot.

When you order the pinch clamps, don't forget to get a roll of UHMW
polyethylene tape. Great for anti-chafe etc. Their number is 76445A12 for
the 1" wide X .0065" X 18 yds.

bumper

My office happens to be about 30 minutes away from their East Coast
warehouse, so I've driven down there on occasion. Talk about a kid in
a candy store - yikes. My wife sees about 2 packages a month from
there between glider fiddling and household projects . She was
beginning to wonder if I'd developed some substance abuse problem, but
all I had to do was mention the glider, and she just shook her head
knowingly.

P3

I'm trying to pin this whole issue down a bit better. Using this web
site ( http://www.mcmaster.com/ ) I found that Eric's translucent, 50
Duro silicone tubing with 3/16" ID and a 5/16" OD is McMaster-Carr P/N
51135K23. It is $0.74 per foot for 10, 20, 50 and 100 foot lengths.

I think O-rings would work better than Bumper's caulking tube clamps,
because I think O-rings will have better quality control. McMaster-Carr
has a mind numbing selection, but specifying 70 Duro silicone rubber
O-rings with a 5/16" ID and a 3/32" width gives McMaster-Carr P/N
9396K74. They are $9.93 for a pack of 100.

What I'm not sure of is the optimal ID and wall thickness. I picked
5/16" OD so they would easily roll over the tubing above, and 3/32"
width because it would be slightly stronger than 1/16" while still not
much more expensive. However, a 1/4" OD with a 1/16" width would surely
hold tighter - but might it distort the tubing to the point of leaking?
I don't know - opinions?

-John

jcarlyle wrote:

What I'm not sure of is the optimal ID and wall thickness. I picked
5/16" OD so they would easily roll over the tubing above, and 3/32"
width because it would be slightly stronger than 1/16" while still not
much more expensive. However, a 1/4" OD with a 1/16" width would surely
hold tighter - but might it distort the tubing to the point of leaking?
I don't know - opinions?

-John

I'm a big believer in the experimental method :-)) You can pick up a
variety pack of o-rings at most hardware stores (even the so-called
"tools section" at Walmart). I'd try a couple first before buying in
volume. My guess is that 5/16" ID with a thicker wall (ie. width)
would work fine; the barbs on the fitting tend to increase the
effective OD of the tubing, but not so much to cause a problem.

If you're in the US of A, try your local ACE Hardware if you have one.
If it's anything like mine, they actually have a good-ole-fashioned
"hardware" section with bins of O-Rings. I feel kind of sheepish (no
pun intended based on earlier tone of this thread) walking up to the
register with 3 o-rings totalling 15 cents, but hey...

P3

Whoa- normal "O" rings? CAUTION! The rubber compounds used in many so-called O rings is not up to the task, UV, Temperature and standard gaseos compounds will break them down in just a few weeks.
If you cant do a test on the ring, like leave it on the cockpit seat for a month or two, stick with a proven thing!

This would be the case for "normal" Buna-N O-rings. It would not apply to
Viton, EPDM "normal" O-rings (g).

If you go into a hardware store and ask for an O-ring, you'll likely get
handed a Buna-N. They do petroleum oils well, but not weather and ozone.
EPDM does DOT brake fluids and resists weather/ozone etc.

bumper

bumper

"bagmaker" wrote in message
...

Whoa- normal "O" rings? CAUTION! The rubber compounds used in many
so-called O rings is not up to the task, UV, Temperature and standard
gaseos compounds will break them down in just a few weeks.
If you cant do a test on the ring, like leave it on the cockpit seat
for a month or two, stick with a proven thing!


--
bagmaker