Making a Canopy

[Guy B]

I have a glider, a canopy frame, and a new plastic canopy, and now my problem is making them all come together into a functioning unit. I've searched this site, and found a bit of info, but still really need some detailed instruction on fastening the plastic to the frame.
I know the frame has to be fitted to the glider first, and the plastic cut, fitted, and glued to the frame, while in place on the glider. I understand that screws aren't necessary, and may in fact cause trouble.
I think I need a fine tooth circular saw, and grinder, some way of clamping, a specific adhesive and info on how to use it. I can't do any of this, but will be working with an experienced aircraft engineer, who is willing to give it a try.

Any help from this community would be appreciated. Or pointers to some place or person who can assist.

Thanks,
Guy
Kestrel 19 CF-FGR

[[email protected]]

On Tuesday, January 21, 2014 3:21:41 PM UTC-5, Guy B wrote:
> I have a glider, a canopy frame, and a new plastic canopy, and now my problem is making them all come together into a functioning unit. I've searched this site, and found a bit of info, but still really need some detailed instruction on fastening the plastic to the frame. I know the frame has to be fitted to the glider first, and the plastic cut, fitted, and glued to the frame, while in place on the glider. I understand that screws aren't necessary, and may in fact cause trouble. I think I need a fine tooth circular saw, and grinder, some way of clamping, a specific adhesive and info on how to use it. I can't do any of this, but will be working with an experienced aircraft engineer, who is willing to give it a try. Any help from this community would be appreciated. Or pointers to some place or person who can assist. Thanks, Guy Kestrel 19 CF-FGR

If you can get the direct assistance of someone that has done this properly before, you would be well advised to do so.
I trim canopies with a disc sander and would NEVER use a saw due to the liklihood of starting cracks.
I use screws with large washers on the perimeter to hold the canopy flush when gluing. No holes are drilled in the plastic.
Most all canopies on glass ships are bonded with epoxy like that used for repairs.
Good Luck
UH

[[email protected]]

On Tuesday, January 21, 2014 3:21:41 PM UTC-5, Guy B wrote:
> I have a glider, a canopy frame, and a new plastic canopy, and now my problem is making them all come together into a functioning unit. I've searched this site, and found a bit of info, but still really need some detailed instruction on fastening the plastic to the frame.
>
> I know the frame has to be fitted to the glider first, and the plastic cut, fitted, and glued to the frame, while in place on the glider. I understand that screws aren't necessary, and may in fact cause trouble.
>
> I think I need a fine tooth circular saw, and grinder, some way of clamping, a specific adhesive and info on how to use it. I can't do any of this, but will be working with an experienced aircraft engineer, who is willing to give it a try.
>
>
>
> Any help from this community would be appreciated. Or pointers to some place or person who can assist.
>
>
>
> Thanks,
>
> Guy
>
> Kestrel 19 CF-FGR

http://www.toddscanopies.com/

Todd's Canopies, Inc.
1445 NE 33rd St., Ft Lauderdale, FL 33334

Phone # : 954-579-0874

Although I havent had a canopy made yet, on the phone Todd sounded very professional and fair with prices. He makes canopies from scratch as well for custom designs. Maybe he would be willing to provide advice to get you started.

Hunter

[Dan Marotta]

It's been 25+ years, but, while building a Quickie Q-2, I seem to recall
peeling back the protective coating on the plexi about an inch or so and
roughing it up with sand paper to promote adhesion. after applying flox (a
mix of epoxy and flocked cotton) around the perimeter of the frame, the
canopy was applied and held in place with duct tape run perpendicular to the
frame.

After setting up, I removed the duct tape, roughed up the outside of the
canopy about 1/2 - 2/3 inch up from the edge, filled with flox and glass
cloth. I'm sure there are better ways these days, but that's how I did it
in the 80s.

> wrote in message
...
On Tuesday, January 21, 2014 3:21:41 PM UTC-5, Guy B wrote:
> I have a glider, a canopy frame, and a new plastic canopy, and now my
> problem is making them all come together into a functioning unit. I've
> searched this site, and found a bit of info, but still really need some
> detailed instruction on fastening the plastic to the frame.
>
> I know the frame has to be fitted to the glider first, and the plastic
> cut, fitted, and glued to the frame, while in place on the glider. I
> understand that screws aren't necessary, and may in fact cause trouble.
>
> I think I need a fine tooth circular saw, and grinder, some way of
> clamping, a specific adhesive and info on how to use it. I can't do any of
> this, but will be working with an experienced aircraft engineer, who is
> willing to give it a try.
>
>
>
> Any help from this community would be appreciated. Or pointers to some
> place or person who can assist.
>
>
>
> Thanks,
>
> Guy
>
> Kestrel 19 CF-FGR

http://www.toddscanopies.com/

Todd's Canopies, Inc.
1445 NE 33rd St., Ft Lauderdale, FL 33334

Phone # : 954-579-0874

Although I havent had a canopy made yet, on the phone Todd sounded very
professional and fair with prices. He makes canopies from scratch as well
for custom designs. Maybe he would be willing to provide advice to get you
started.

Hunter

[[email protected][_1_]]

This is not a trivial exercise, a lot of work, a great deal of risk (Canopy = $$$) and a really suboptimal place to start learning composite work.

I have about 5 pages of really minor but very important details on this process that I consult ever time I mount a canopy and this is not my first rodeo.

Cut canopies with abrasive cutoff wheels and disc sanders, never with toothed devices.

Some installers use countersunk metal screws in addition to bonding (epoxy + cotton flox + fumed silica. Screws are mostly to hold alignment and position while the epoxy cures.

Rubber bands made from bike inner tubes are very handy for holding the plexi on the frame while it cures.

I cannot think of a more difficult, detail-critical installation than this.

How far are you from Dave Nelson in MI or M&H in NY?

[Bob Kuykendall]

Some few general points I have to add:

* Don't even look at the transparency cross-eyed unless it and the frame are above 70 degrees F. Don't drill it, don't cut it, unless it is toasty warm.

* Consult the manufacturer about what to bond the canopy on with. In general, avoid using epoxies that are thinned for laminating. If it's thin enough to saturate cloth, chances are good that it might be thinned with something that will attack and craze the acrylic. I use Epon 828/Versamid 140, the same resin/hardener combo that I also use to join large fuselage and wing skins to each other.

Thanks, and good luck!

Bob K.
HP-24 Kit Sailplane Project
https://www.facebook.com/pages/HP-24-Sailplane-Project/200931354951

[Jim Crawford]

Ibelieve that DG now bond their transparencies to the frame and have a
specific procedure and adhesive to achieve this. Could be worth contacting
them or their agent to get details.

Jim


At 20:21 21 January 2014, Guy B wrote:
>I have a glider, a canopy frame, and a new plastic canopy, and now my
>probl=
>em is making them all come together into a functioning unit. I've
>searched=
> this site, and found a bit of info, but still really need some detailed
>in=
>struction on fastening the plastic to the frame.=20
>I know the frame has to be fitted to the glider first, and the plastic
>cut,=
> fitted, and glued to the frame, while in place on the glider. I
>understand=
> that screws aren't necessary, and may in fact cause trouble.=20
>I think I need a fine tooth circular saw, and grinder, some way of
>clamping=
>, a specific adhesive and info on how to use it. I can't do any of this,
>bu=
>t will be working with an experienced aircraft engineer, who is willing
to
>=
>give it a try.=20
>
>Any help from this community would be appreciated. Or pointers to some
>plac=
>e or person who can assist.
>
>Thanks,=20
>Guy=20
>Kestrel 19 CF-FGR
>

[Dave Martin[_3_]]

I have repaired maby canopies, but never been brave enough to
attempt a replacement of a bubble.

A friend has just replaced the bubble on her glass glider.

Canopies are moulded specifically for the frame they are to fit.

On glass gliders screw are normally used. but the canopy is
bonded to the frame using a high quality, one-component
polyurethane adhesive-sealant.

My friend used a product called CARBOND.

An internet search shows Carbond 940FC product details and data
sheets.

I would add that my friend had the help and advice of an
experienced inspector/engineer not only to ensure success but also
to ensure she had the signatures when the job was complete to
ensure the glider was airworthy.

[[email protected]]

On Tuesday, January 21, 2014 2:21:41 PM UTC-6, Guy B wrote:
> I have a glider, a canopy frame, and a new plastic canopy, and now my problem is making them all come together into a functioning unit. I've searched this site, and found a bit of info, but still really need some detailed instruction on fastening the plastic to the frame.
>
> I know the frame has to be fitted to the glider first, and the plastic cut, fitted, and glued to the frame, while in place on the glider. I understand that screws aren't necessary, and may in fact cause trouble.
>
> I think I need a fine tooth circular saw, and grinder, some way of clamping, a specific adhesive and info on how to use it. I can't do any of this, but will be working with an experienced aircraft engineer, who is willing to give it a try.
>
>
>
> Any help from this community would be appreciated. Or pointers to some place or person who can assist.
>
>
>
> Thanks,
>
> Guy
>
> Kestrel 19 CF-FGR

First off, I would seek professional assistance. This is a major undertaking, even for someone who has experience.

Here are some suggestions that hopefully will help steer you in the right direction.

1. You can start by protecting the canopy from scratches and scuffing by using Spraylat. This is a water based compound that can be painted or sprayed on the canopy that leaves a thin rubber coating. You can peel back the coating on your mating surfaces for bonding and peel off the rest upon completion of the project.

2. Turn the heat up and only work on the project when the canopy and environment are above 70 degrees, 80 works even better.

3. When you trim the canopy only use high speed cut off wheels or a drum sander. Using any type of a saw will cause chipping and stress fractures.

4. Fit the canopy frame to the glider for a good fit to start with. When you bond the canopy to the frame, do so when the frame and canopy are in place on the sailplane. If you bond it to the frame off of the sailplane you will end up with a twist and poor fit. I used 3M Panel Bond that is a two part adhesive. When it hardens it will still be somewhat pliable which is what you want for the environmental thermal expansion/contraction.

5. Don't drill any holes thru the canopy as this may introduce stress cracks at a future date. I used bicycle inner tubes stretched over the structure for bonding with localized wood blocks between the tubes and canopy around the frame for a tight fit.

6. My last suggestion is to cut the canopy 1/8" short around the perimeter and fill in the gap with micro. This suggestion if for impact resistance. The micro will take the hit instead of the Plexiglas. If the Plexiglas takes the hit it may propagate a stress crack.

Chris

[Dan Marotta]

....Or Applebay (Fidel) in NM?


> wrote in message
...
> This is not a trivial exercise, a lot of work, a great deal of risk
> (Canopy = $$$) and a really suboptimal place to start learning composite
> work.
>
> I have about 5 pages of really minor but very important details on this
> process that I consult ever time I mount a canopy and this is not my first
> rodeo.
>
> Cut canopies with abrasive cutoff wheels and disc sanders, never with
> toothed devices.
>
> Some installers use countersunk metal screws in addition to bonding (epoxy
> + cotton flox + fumed silica. Screws are mostly to hold alignment and
> position while the epoxy cures.
>
> Rubber bands made from bike inner tubes are very handy for holding the
> plexi on the frame while it cures.
>
> I cannot think of a more difficult, detail-critical installation than
> this.
>
> How far are you from Dave Nelson in MI or M&H in NY?
>

[Andrew Brayer]

On Tuesday, January 21, 2014 3:21:41 PM UTC-5, Guy B wrote:
> I have a glider, a canopy frame, and a new plastic canopy, and now my problem is making them all come together into a functioning unit. I've searched this site, and found a bit of info, but still really need some detailed instruction on fastening the plastic to the frame.
>
> I know the frame has to be fitted to the glider first, and the plastic cut, fitted, and glued to the frame, while in place on the glider. I understand that screws aren't necessary, and may in fact cause trouble.
>
> I think I need a fine tooth circular saw, and grinder, some way of clamping, a specific adhesive and info on how to use it. I can't do any of this, but will be working with an experienced aircraft engineer, who is willing to give it a try.
>
>
>
> Any help from this community would be appreciated. Or pointers to some place or person who can assist.
>
>
>
> Thanks,
>
> Guy
>
> Kestrel 19 CF-FGR



PLEASE PLEASE PLEASE get help from a professional, or send it to a professional. this is a detail oriented process and they can go horribly wrong. a canopy is too expensive to risk it. you have to think about fitting it properly, not having glue overflow, not accidentally gluing the frame to the glider, painting it so that it doesn't look awful et. cetera... the list of potential problems goes on an on.

[[email protected]]

On Wednesday, January 22, 2014 1:14:01 PM UTC-5, Andrew Brayer wrote:
> On Tuesday, January 21, 2014 3:21:41 PM UTC-5, Guy B wrote: > I have a glider, a canopy frame, and a new plastic canopy, and now my problem is making them all come together into a functioning unit. I've searched this site, and found a bit of info, but still really need some detailed instruction on fastening the plastic to the frame. > > I know the frame has to be fitted to the glider first, and the plastic cut, fitted, and glued to the frame, while in place on the glider. I understand that screws aren't necessary, and may in fact cause trouble. > > I think I need a fine tooth circular saw, and grinder, some way of clamping, a specific adhesive and info on how to use it. I can't do any of this, but will be working with an experienced aircraft engineer, who is willing to give it a try. > > > > Any help from this community would be appreciated. Or pointers to some place or person who can assist. > > > > Thanks, > > Guy > > Kestrel 19 CF-FGR PLEASE PLEASE PLEASE get help from a professional, or send it to a professional. this is a detail oriented process and they can go horribly wrong. a canopy is too expensive to risk it. you have to think about fitting it properly, not having glue overflow, not accidentally gluing the frame to the glider, painting it so that it doesn't look awful et. cetera... the list of potential problems goes on an on.

My friend JJ used to call stuff like this "do it yourself brain surgery".
UH

[Dave Nadler]

Please make a video; we are all looking forward to
seeing the demolition on YouTube...

[Craig Funston[_2_]]

On Wednesday, January 22, 2014 1:00:27 PM UTC-8, Dave Nadler wrote:
> Please make a video; we are all looking forward to
>
> seeing the demolition on YouTube...

Just be glad you're not doing a Libelle or something where you can't lay the canopy blank over the cockpit to mark something close to the net shape. The biggest problem with canopy work is the high cost of failure. The advice to work with warm materials, use an abrasive cut-off wheel and have the frame locked down on the fuselage when mounting the plastic is critical. Beyond that it's just a myriad of details.

Hope all goes well,
Craig

[John Firth[_4_]]

gluing the canopy.
About 35 years ago, I was using ( and still do)silcone RTV for a wide
variety of jobs needing a gap filling glue.
I repaired an extensively damaged Kestrel, with a smashed canopy.
I dislike screws for holding plexi. After doing test samples,
the canopy was glued with clear silicone RTV (type I)
using a commercial primer on both surfaces .
this method avoids localised stress and was OK for ten years.
I recently saw this gl;ider for sale with a canopy which
looked like the blue tinted canopy I installed.
PS yes, cut the plexi using a cutoff flexi disc. I melts and
aneals the cut surface.
JMF


At 02:42 22 January 2014, wrote:
>This is not a trivial exercise, a lot of work, a great deal of risk
(Canopy
>= $$$) and a really suboptimal place to start learning composite work.
>
>I have about 5 pages of really minor but very important details on this
>process that I consult ever time I mount a canopy and this is not my
first
>rodeo.
>
>Cut canopies with abrasive cutoff wheels and disc sanders, never with
>toothed devices.
>
>Some installers use countersunk metal screws in addition to bonding
(epoxy
>+ cotton flox + fumed silica. Screws are mostly to hold alignment and
>position while the epoxy cures.
>
>Rubber bands made from bike inner tubes are very handy for holding the
>plexi on the frame while it cures.
>
>I cannot think of a more difficult, detail-critical installation than
this.
>
>How far are you from Dave Nelson in MI or M&H in NY?
>
>

[Guy B]

What a great response! I was away for a while and just signed on again. The words of wisdom and caution are greatly appreciated. I'll show all comments to the aircraft engineer that thinks he might be able to do it. I expect we'll be looking for that special someone who has some good experience. Thanks again.
Guy
Living in Alberta and Nevada

[JJ Sinclair[_2_]]

On Sunday, January 26, 2014 1:49:10 PM UTC-8, Guy B wrote:
> What a great response! I was away for a while and just signed on again. The words of wisdom and caution are greatly appreciated. I'll show all comments to the aircraft engineer that thinks he might be able to do it. I expect we'll be looking for that special someone who has some good experience. Thanks again.
>
> Guy
>
> Living in Alberta and Nevada

Guy,
I see you live in Nevada some of the time. If you fly Minden, I would be glad to cover the do's and don'ts of cutting, drilling, gluing and painting a replacement canopy. Look for a bat looking sailplane with JJ on the fin and introduce yourself.
JJ