Cost to install a canopy?

Tim has provided a pretty good summary of the process. Some notes on
canopy transparencies in no particular order:

* As Tim pointed out, mounting canopies takes time and experience to do
right. As with most things, the best results are had the second or
third time you do it. Your best bet is to find a shop that's done it
before so you don't end up paying for the shop's education.

* Though the work is fussy, takes rather a lot of time to do properly,
and requires a good eye and somewhat delicate touch, it can be done in
the home workshop environment. If you've done good-looking bodywork
with Bondo and paint, you can probably mount a canopy. At very least,
you can probably do some of the prep work. But consult with your A&P
before starting. If you've done owner-assisted annuals (the best kind,
I think) and have a good relationship with the A&P, they might be OK
with it. Or, they might not. Ask first to avoid surprises.

* Usually the preferred bonding techniques and materials are shown in
the maintenance manual. You can also pick up some general hints by
looking at the tech notes for different gliders. The DG tech notes in
particular show a neat trick for using foam tape for controlling
squeeze-out of the bonding resin.

* Bonding the transparency onto the frame without having the frame on
the fuselage is very risky, and I've seen it result in an
embarassing-looking assembly that barely fit onto the glider at all. I
definitely don't recommend it. Canopy frames tend to be fairly
lightweight parts, and a lot of the strength and stiffness of the
canopy assembly comes from the transparency. Also, the frame is often
painted black so it sometimes gets hot and takes on a warp that only
shows up when it is separated from the transparency. All the big
companies have tooling that emulates the cockpit rail that they clamp
the frame to when bonding in the transparency.

* Acrylics are much more crack-prone when they're cold. If you feel
tempted to work acrylics such as Plexiglas, don't do any cutting,
drilling, or filing operations unless the plexi itself (and not just
the room it's in) is warmed up to at least 70 degrees F and preferably
in the 80s F.

* If the preferred bonding resin isn't shown in the tech notes and you
have to choose your own, I suggest _not_ using an epoxy thinned with
butyl glycidal ether (as are most laminating resins) - it crazes the
acrylic. George Applebay has recommended Epon 828 kicked 2:1 with
Versamid 140. I haven't tried it myself, but I will.

* Last time I checked, the manufacturers were paying 500 to 1200 Euro
for transparencies of various sizes in lots of ten or so. Contrary to
popular belief, Mecaplex quite often has the best prices in Europe for
the raw transparencies. The big markups start when it leaves Mecaplex
or wherever, and the glider manufactuer and all the middlemen and the
shippers and insurers get their cut. That's just the way commerce
works.

* Right now acrylics sheet prices are spiking to follow oil prices, so
be prepared for some degree of sticker shock.

* Anybody who wants is welcome to develop their own tooling and place
an order for ten or so and become part of the game themselves. But I
don't think that you can contact Mecaplex directly and order Discus or
ASW-27 canopies. Usually, the glider company develops the canopy
tooling and then hands it off to the transparency company with the
agreement that they will only make transparencies on that tool for that
glider company.

* Anybody who ever thinks of making their own canopy transparencies
should count on not getting usable results until somewhere between the
third and sixth attempt. It's a tricky business, and the major players
guard their trade secrets jealously. Way more often than not, the most
cost-effective way of getting a good transparency is to buy it from a
reputable firm such as the sailplane manufacturer.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com/hp-24

I just finished putting a new canopy on my Phoebus and it took about 60
hours to do. I know it can be done quicker by a more experienced
technician, but it is labor intensive. A lot depends upon how difficult
it is to remove the old canopy and any required prep work to repair the
frame when the old canopy is removed.

Mike

Hi Roger,

I have recently installed a new canopy on my Phoebus C and it took
about 60 hours. Im sure if I did a second it would require less time.
Im aware that 40 hours is about standard for an installation if the old
canopy has been removed.

If you are thinking of a new canopy due to cracks, you may be
interested that there are ways to repair cracks that removes the crack
and the repaired area is much less apparent.

Good luck,

Mike

Here is an article I found on how to make the canopy blank yourself:

http://www.sportaviation.org/magazin...mer/canopy.pdf

Still, it is a fair amount of effort for one canopy.

Tom

Roger,

Tons of good posts here. FWIW, I've done a couple of canopy repair jobs
(not complete replacements), and everything mentioned elsewhere holds
true:

- It's doable if you are average to above-average handy with tools and
finishing work.
- Figure out how long you think it will take. Then triple that
estimate.
- It can be very satisfying.
- The downside risk is pretty high.

I'm probably in the "above average" category in terms of experience
working with filler,epoxy, and finish sanding, and I've managed to get
results ranging from decent to spectacularly poor. If the canopy is
already in pretty bad shape, then attempting a home-grown repair or
refurbish may not be such a bad thing. You might learn something, and
the worst that happens is you have to get the new canopy after all.

Erik Mann (P3)

I manufacture Transparencies for a living.
Mostly windshields for sports cars. There are so
many places to screw up that it can be a truly
humbling experience. What puzzles me is that
most folks give little atention to the canopy as
it ages. You can double the life of a canopy
by keeping it squeaky clean and polishing the
surfaces at least annually. Proper polishing
doesn't remove material from the plastic, it removes crap
from the plastic. Micromesh is NOT a polishing system
it is much too agressive, it is for repair work. Even
with normal care, the exterior (interior also) will eventually
degrade and start to produce chalk like deposits as the
monomers in the plastic sublimate. Once it gets to this
state, you basically are on life support. If you have
a canopy that is so old it just won't polish well,
Micromesh probably won't help as the sublimation is
in most cases deeper than the max grind depth of the system.
When you get to this place, toss the book aside, and get a bit creative.
The object of the game is now to stop sublimation and seal the canopy
surface with something you can see thru. Believe it or not, the
green can TURTLE WAX will make things a lot better. It
will fill the small scratches and surface pores and get you back
to a usable canopy surface. The downside is that it stops the canopys
ability to breathe and adjust to humidity changes which will cause
a higher internal hoop stress load to exist and make the canopy less
forgiving to bumps and racking. DON'T do this to a canopy with
life left in it, but when the choice is this or a replacement, I like doing
this first.
I've got some vintage race cars going on 5 or 6 years doing this. They
are one step from the grave as far as repairability, but they still work ok
enough to use. As far as day to day maintenance, a couple thoughts.
First, Plexiglass (PMMA) isn't really a solid. It is an incredibly viscous
liquid and is pourous. This means that the stuff it is made of can
"evaporate"
(sublimate) over time. It also means that stuff you put on it can "go into
suspension" inside the plastic. This is why I cringe so bad when I see
Lemon Pledge used on a canopy. Not only is the propellant, usually
isobutane, (a great solvent I might add) trapped inside the canopy by the
wax
so it can disolve the internal structure of the plastic, but the free
breathing of
the plastic and its ability to adjust its relative humidity are compromised.
Dust can do the same thing, it will plug the plastic pores and in most cases
it is acidic and will react adversely to the plastic. So what to do.
Keep a piece of dry flannel on the canopy when you aren't using it. Only
use good quality plastic cleaners designed for the plastic you have. Always
start a canopy cleaning with clear water to get the dust off the canopy
before you start smushing it into the plastic with your cleaning rag.
Only use soft cotton to clean the canopy, old diapers are the gold
standard. I hope this helps, and no, I'm not looking for canopy work....

Scott.

pbc76049 (removethis) wrote:
I manufacture Transparencies for a living...

Spectr Scott, I been trying to get ahold of you. Drop me an email when
you can.

Thanks, Bob K.

I've replaced a couple of Grob canopies, but it has been over 10 years
ago. Each went like this -

Tools -
Air powered die grinder with sanding disks and cutoff wheel
Screwdriver
Foil tape
Plastic drill and countersink
Small paint gun


Day one -
With the frame in place on the glider I used the grinder with sanding
disk and removed the gel where it contacts the frame. Cut off the
remaining canopy next to the frame with a cutoff wheel. (I once saw a
Grob mech beat one off with a hammer.) Chiseled and ground off all
plastic and the resin used to bond it to the frame. Grob uses small
screws to hold it place while the resin cures. Ground those off also.
(Approx 4 hours)

Day two-
The canopy comes oversize. Placed it on the still in place frame and
adjusted its position while overlapped and taped in place with clear
tape. Ran the cutoff wheel around and used the frame edge as a guide
removing all excess. Taped again in place. Drilled and countersinked
holes for small brass screws using a drill modified for plastic
(careful here or you'll break it). Removed canopy and put a bead of
resin on the frame. Pealed back the protective plastic around the
edge. Put it back on and lightly (real lightly) screwed it down.
(Approx 4 hours)

Day three-
Masked off at the level of the frame with metal foil tape. Hand
sanded the canopy edge to roughen and remove the resin squeeze-out.
Filled the gaps and screw heads with white Bondo and block sanded
level. Shot on gel coat with a touchup gun. After it cured, sanded
and polished the gel. Removed all the tape and protective plastic.
Cleaned and waxed it. Signed off the work in the log. (Approx 6
hours)

The moral(s) of the story is that it's not a huge task, break it and
you'll buy another, and these are hand built aircraft. The frame from
one probably won't fit another. Leave the frame in place while you
change the glass and it will fit like the original. Most of all, this
is how I did it. What you do is at your own risk. ;-)

Hello Roger, i have a gas station where i want to get canopy installed
If u can email me at

I believe you want an awning type thing, we are talking about clear/tinted plastic over the cockpit of an aircraft.

Try another Google search.

;-)