Cost to install a canopy?

On Thursday, December 8, 2005 at 9:40:42 AM UTC-5, Roger Worden wrote:
Our club is looking into a new canopy for a Grob 103 Twin Astir. We received
an estimate from a well-known repair shop: $2,000 for the canopy and 50
hours of labor to install. I'm new to this field - I fly 'em, I don't fix
'em. But I'm having a hard time imagining what steps must be involved to
consume 50 hours. Hinge, latches... what am I missing?

after removing the old canopy, which includes lots of chipping t the frame with a chisel, you have to prep the frame with a grinding disc. basically you are making space for new glue. then you have to trim the canopy to size. (a slow, careful process requiring lots of concentration.) there are many test fits you have to do. then once the frame is prepped and the canopy is cut to size, you scuff the inside of the class where it will contact the frame. you have to apply a seal strip to the frame perimeter to keep glue from overflowing into the cockpit side of the canopy frame. after the canopy is glued, you have to sand the perimeter of the frame, if not stripping it completely. sometimes there is some fitting work required with bondo, then there is priming (if done in urethane) you have to sand that primer. and spraying of paint or gelcoat. then you sand that. if you sand through the paint/gelcoat, which often happens on the first attempt, you have to do touch up spraying, then sand that. by the way, sanding in this case involves working through several grits from 320 to 1500. then you can polish it. after that you clean up the edges, and generally the glider it self needs to be cleaned up as well. its definitely 50 hours of work. that's probably even a little generous.

$6000. $3000 for canopy and $3000 labor. Three canopies over five years different club and private ships. Fitting is the art. Wheaton

On Wednesday, November 15, 2017 at 1:46:06 PM UTC-5, Wheaton wrote:
$6000. $3000 for canopy and $3000 labor. Three canopies over five years different club and private ships. Fitting is the art. Wheaton

The PIK-20 group has just done a group order and they came out to just over $1800 for a tinted canopy, no labor included.

On Wednesday, November 15, 2017 at 11:46:06 AM UTC-7, Wheaton wrote:
$6000. $3000 for canopy and $3000 labor. Three canopies over five years different club and private ships. Fitting is the art. Wheaton

I'm not sure there is much art to the fitting.

Look at the description of Don Hammer earlier in this post:
"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... Removed canopy and put a bead of
resin on the frame."

There is no fine fitting here. I'm removing my old canopy in prep for a replacement and find that the edge is uneven by millimeters, which fillers compensate for. Good adhesives have several thousand psi strength in tension and shear, so the adhesive takes the canopy load, not canopy to frame-lip contact.

The PIK-20 group has just done a group order and they came out to just over $1800 for a tinted canopy, no labor included.

We're having them made now in CA. $1510 per canopy tinted with window, plus $150 to $300 shipping.

On Tuesday, November 28, 2017 at 5:02:04 PM UTC-5, Bret Hess wrote:
On Wednesday, November 15, 2017 at 11:46:06 AM UTC-7, Wheaton wrote:
$6000. $3000 for canopy and $3000 labor. Three canopies over five years different club and private ships. Fitting is the art. Wheaton

I'm not sure there is much art to the fitting.

Look at the description of Don Hammer earlier in this post:
"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... Removed canopy and put a bead of
resin on the frame."

There is no fine fitting here. I'm removing my old canopy in prep for a replacement and find that the edge is uneven by millimeters, which fillers compensate for. Good adhesives have several thousand psi strength in tension and shear, so the adhesive takes the canopy load, not canopy to frame-lip contact.

Do it yourself brain surgery isn't a big deal either. Just get out the drill and go for it.
I've done about 20 canopies and all require some degree of "fine fitting". Some not much. Some as much as 12 hours just fitting. If the canopy is not properly fitted it won't match the contours of the glider and will look like junk.
UH

There is no fine fitting here...

Yeah, I've seen lots of gliders like that.

I have fitted a couple of canopies, and I can say that the more effort and attention you put into it, the better it turns out. The fit of the canopy transparency to the frame, and the assembly to the fuselage, is the first and last thing you see when you get in and out of a glider, so it's nice when it it all looks good.

Pretty much anyone can learn to do it, but when you learn by doing the lessons are too often too late for the learning.

Some points from our experience:

* If you fit the canopy so that the edge is proud of the contour, you can always add a bit of filler to the fuselage and make it look just fine. But if you fit the canopy so that the edge is below flush of contour, it is much harder to deal with.

* Canopy frames often have built-in stresses and preloads that spring them out of shape when the transparency is removed. So it is usually best to fit the canopy while the frame is mounted to the fuselage and maybe has a few spring clamps to hold it into place on the fuselage.

* Canopy transparencies are often not very consistent in thickness around the perimeter; this is a side effect of the stretch forming operation. So don't expect to create an inset the exact canopy thickness and have it come out perfect. The thickness varies, and you also need room for the bonding paste.

* It might be an old wives tale, but I've been told that the BGE diluents in laminating epoxies can attack and craze acrylics. In my shop we use an undiluted bonding resin for canopy transparencies, just in case.

* Squeezeout happens. Use lots of masking tape, and wax the fuselage and everything else you don't want stuck together. The DG guys actually use a narrow strip of weatherstripping along the upper edge of the canopy frame to keep the squeezeout from coming up and into the cockpit. I've not tried that, but it sounds like a good idea.

* Do not attempt to cut, drill, sand, or file the transparency unless it is above about 70 degrees F. Fresh acrylic plastic is actually quite easy stuff to work with when it's warm. But like glider pilots, the colder and older canopies get, the more disagreeable they become.

--Bob K.

On Tuesday, November 28, 2017 at 6:09:15 PM UTC-6, Bob Kuykendall wrote:
There is no fine fitting here...

Yeah, I've seen lots of gliders like that.

I have fitted a couple of canopies, and I can say that the more effort and attention you put into it, the better it turns out. The fit of the canopy transparency to the frame, and the assembly to the fuselage, is the first and last thing you see when you get in and out of a glider, so it's nice when it it all looks good.

Pretty much anyone can learn to do it, but when you learn by doing the lessons are too often too late for the learning.

Some points from our experience:

* If you fit the canopy so that the edge is proud of the contour, you can always add a bit of filler to the fuselage and make it look just fine. But if you fit the canopy so that the edge is below flush of contour, it is much harder to deal with.

* Canopy frames often have built-in stresses and preloads that spring them out of shape when the transparency is removed. So it is usually best to fit the canopy while the frame is mounted to the fuselage and maybe has a few spring clamps to hold it into place on the fuselage.

* Canopy transparencies are often not very consistent in thickness around the perimeter; this is a side effect of the stretch forming operation. So don't expect to create an inset the exact canopy thickness and have it come out perfect. The thickness varies, and you also need room for the bonding paste.

* It might be an old wives tale, but I've been told that the BGE diluents in laminating epoxies can attack and craze acrylics. In my shop we use an undiluted bonding resin for canopy transparencies, just in case.

* Squeezeout happens. Use lots of masking tape, and wax the fuselage and everything else you don't want stuck together. The DG guys actually use a narrow strip of weatherstripping along the upper edge of the canopy frame to keep the squeezeout from coming up and into the cockpit. I've not tried that, but it sounds like a good idea.

* Do not attempt to cut, drill, sand, or file the transparency unless it is above about 70 degrees F. Fresh acrylic plastic is actually quite easy stuff to work with when it's warm. But like glider pilots, the colder and older canopies get, the more disagreeable they become.

--Bob K.

On Tuesday, November 28, 2017 at 2:02:04 PM UTC-8, Bret Hess wrote:

I'm not sure there is much art to the fitting.


That opinion may change after the canopy cracks due to stress in extreme temperatures.
Jim

On Tuesday, November 28, 2017 at 2:02:04 PM UTC-8, Bret Hess wrote:

I'm not sure there is much art to the fitting.

That is one of the more assuming thing I've read on r.a.s. Please post photos of your transparency installation progress.