Canopy

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Canopy

This page chronicles installation of the canopy - the most dreaded task of building a RV-8.

First, the canopy slider and canopy frame must be fitted.

	The slider is taped in position in prep for drilling the mounting holes. Right is a closeup of the canopy slider where it drops into the fuselage
	Left is the slider installed with the frame in place. Right shows plans detail of canopy side rail

	I got some hoses to uses as spacers on the canopy frame as I Sika Flex it to the canopy.
	Above is the Sikaflex adhesive, primer and cleaner. Above right are the hose spacers used to hold the canopy away from the frame to get the proper thickness of adhesive. Lower photos show the spacers in place.

Trimmed the top front skin where the canopy meets it. Had to trim both sides to slide the canopy full forward. Cut more hose pieces for the canopy gluing. Got started on cutting the canopy excess but my diamond Dremel cutter is wearing out and I had to stop - I'll buy a new one tomorrow. The diamond cutter works very good for cutting the canopy - although it is very expensive.

I placed the uncut canopy on the fuselage to get an idea of where I was heading. I should have marked a centerline before starting the trimming.

Finished cutting the canopy and made the second trim cut on it.

	After the first cut the canopy is still riding high
	It is resting on the front and rear ends of the canopy. Some say that it is better to trim the front to fit and then the aft end. However, that advice is coming from tall guys. I believe I will trim them simultaneously so as to get a more aerodynamic profile. The rear canopy frame still has to be bent down until it is within 5/8" to 3/4" of the slider.

Made a second cut on the canopy which allowed it to sit a little lower. It appears that the Van's markings are reasonably close to being correct. I'm still going to inch my way to them. Went to Harbor Freight today and got small clamps to hold the canopy in place for gluing and found some cheap diamond cutters to use on the canopy.

Trimming the canopy 1/4" at a time. But. it's coming into shape. It's almost trimmed enough to rest on the roll bar. The diamond cutters used in a Dremel-type tool works good for cutting the plexi. I use a shop vac while making the cut to keep the dust and debris to a minimum.

Okay. Lesson learned. Never lift your canopy alone.

I made the final fitting cut and was lifting the canopy onto the fuselage for the final fitting before quitting for the night. I know I should never do anything critical late at night when I'm tired. Anyway, I put too much pressure on the side and POP! - it broke!!

My heart sank. After hours of trimming and fitting and now this.

I've already sent an email to Todd Silver of Todd's Canopies to see how much it will cost for a new one.

Damn!

Opened the Todd's canopy box to discover it is longer than the original canopy and the windscreen is more sloped. It is also darker than I expected. On the phone, Todd told me that someone convinced him several years ago to make the windscreen 2.5 inches longer than Van's. Personally I'd prefer an exact duplicate of Van's canopy, but I can work with this one.

Began trimming the new canopy, but something just didn't seem right. A little investigation discovered that about 4 years ago I mounted the canopy slider 0.10 inches off center to the right. That doesn't sound like much, but it is just enough to make fitting the canopy more difficult than it needs to be. We could make it work, but I'm just not happy with it. Nelson suggested that we could remove and remount the slider by riveting in new metal for those slider mounting screws that needed to be moved. That is what we're going to do. I cannot figure out why I mounted the slider a tenth of an inch too far to the right. Once corrected, I will resume the canopy trimming and fitting.

Worked on trimming the canopy and fitting the oil door. The canopy takes many iterations of trimming and fitting. After about five trimmings today, I think one more will do it and we can drill some holes to fix the canopy location. That will make it easier to get the canopy back in the same spot each time. We will also cut the windscreen away from the canopy then. Tomorrow I'll make a carrier for the canopy frame to make handling it easier.

We used the canopy shipping box to hold it inverted while trimming the edge.

More canopy trimming. The fit seems to be different each time we trim and fit. After a full day of trimming, we finally reached a point where we're ready to drill alignment holes to fix the canopy location. Now I'm contemplating using a number of screws with a grommet or rubber washer between the plexi and the bow/frame in addition to the Sikaflex adhesive.

Started out trimming the canopy again. We have it resting on the roll bar and we looked at using only Sikaflex to attach it, but I believe it will be easier to set the canopy location by drilling some alignment holes. Also, I'd like to mechanically attach the plexi by using a few screws along with the Sikaflex. So, I ordered some small grommets to fit between the plexi and the metal tube. We'll follow up with Sikaflex to secure it all. But, we can't progress on the canopy until the grommets arrive.


The canopy frame is clumsy to handle and it will become even more so once the plexi and skirt are added, so I copied an idea from another guy's web site to make a canopy carrier.	Made it from 2x2 lumber and two 1/2" carriage bolts. The aft end of the frame simply rests on the vertical support. I could drill a hole for it to rest in, but I think I'll let that wait until after painting the frame.	The carrier provides a storage spot for the skirt until it's attached. Here the frame is taped with vinyl tape and ready for painting the interior color. When the tape is removed the original sanded powder coat is exposed for the Sikaflex to adhere to.

It's the day before Christmas - and we made the BIG CUT. Everything was ready and no reason to wait, so we positioned the canopy for the last time, drilled a few alignment holes, clecoed on the canopy and cut the slider portion away from the windscreen. I'm glad that's done. Next we'll start fitting the skirt and prepping for the Sikaflex canopy adhesion. I'm going to use some screws in the windscreen to attach it to the roll bar, but most of the canopy will be attached using only adhesive.


We got the frame painted leaving the strips where the Sikaflex will adhere as sanded powdercoat and put the frame back on the plane.	We put the canopy in place and drilled alignment holes and clecoed on the canopy. We used the plexi drill bits to cut through the canopy and then used #40 to cut into the roll bar. That fixed the canopy position.	We lifted the canopy frame up tight against the canopy and used spring clamps to hold it. Notice the clamps are angled upward so as to drill the mounting holes for the canopy rollers. Be sure to measure and drill a pilot hole before putting the frame on the fuselage so drilling the roller holes is easier. We neglected that step. Once the frame is up as high as it would go, we drilled some alignment holes in the remainder of the canopy.

We removed the canopy and, using Van's recommendation, fit a thick piece of cardboard between the roll bar and the frame - the Todd's canopy box worked great for that. But, before we put the frame on, we drilled out the roller mounting holes to #12 bit and temporarily installed the #10 structural screws.	Then the canopy went back on the plane.	We removed the self adhesive thick plastic from the old Van's canopy and put it on for some protection.
Then, we made the BIG CUT. It was actually anti-climatic after all the preparation was done. I used a Dremel-type tool with a thin diamond blade and it sliced through the canopy like butter. Next we'll need to sand and polish the edges and then on to the Sikaflex.


We drilled all the windscreen holes and tapped part of them. It looks like the 3/16" grommets will work good for attaching the windscreen and allowing space for the Sikaflex adhesive to fill in.	We drilled holes for a handle in the roll bar and installed it.

I decided to make my own wooden mold to make a fiberglass glare shield on. The others I've seen were a bit too high for me and the center section wasn't wide enough. Plus they didn't allow enough room under them to hide the GPS antennae, so I'm making my own. When it's finished we'll tape it, add mold release, and layup a fiberglass glare shield. By designing my own, I can accommodate the LED flood lights and avoid hiding any cockpit displays. I could also mount warning lights, switches, AOA or other things there, but for now, I don't plan to have anything mounted in the edge of the glare shield.


After gluing the middle flat portion, I made side pieces to fit and glued them on with Gorilla Glue.	After removal from the airplane it was still a bit rough, but sturdy.	I had to do some sanding to make both sides symmetrical and to even out the edges. Also had to trim the leading edge to fit behind the windscreen. I have to trim it some more then we'll tape it off and lay glass over it.


I gradually sanded and filed the wood mold into the desired shape. I wanted room under the glare shield for two GPS antennae and the MRX antenna. Plus it will shield the panel LED flood lights.	I had to cut down the forward edges some more and do mare sanding, but it is finally getting close to the final shape. The center aft edge is split and drilled to clamp to the top fuselage skin.	We draped fiberglass over the glare shield and cut it to shape. We cut three layers.

Along the aft edges we allowed enough glass to wrap up under the edges.	We completely taped the wooden mold and the fuselage so the resin won't adhere. Here the 3 layers of glass are finished and we added peal ply to absorb excess resin, create a smoother finish, and hold the glass under the aft edges. We taped the peal ply underneath to hold the glass until it cures.	The forward edges weren't perfect, but they should be fine with a little work. Later I'll add about four screws with standoffs to hold the shield in place.

We must be getting better at fiberglass work because both the intake glass and the glare shield glass have turned out well. Getting the glare shield glass off the airplane took a few minutes, but with determination it finally came off.


Here is the fiberglass glare shield just after we took it off the plane.	It needs some trimming, but overall, it turned out very nice.	I had drilled two alignment holes on centerline and inserted #40 screws to pull the wood mold tight to the fuselage knowing that we could use them for final attachment to the fuselage. Here we have awls through the holes. This is after the initial trimming. For some reason, I didn't take a shot after the final trimming.

We've installed the nutplates for the mounting screws using pop rivets and the GPS antennae are mounted. The MRX antenna is next and all will be hidden by the glare shield.	To keep the fiberglass from pulling down when the mounting screws are inserted, we needed standoffs to take the pressure. One was 0.62 in. long and the other was 0.60. They're made from aluminum tubing and are attached with Goop.	The only shot after the final trimming. It shows another view of the standoffs and where slurry was added inside where the screws holding the wooden mold in place had left their mark. We'll sand them back down and they will disappear. We trimmed the glare shield until it would fit with the windscreen in place so it will be removable in the future.

Got a bit more done on the glare shield. Added the MRX antenna and sanded down the glare shield. Ordered a MRX antenna extender.


Here are all of the planned antennae as they will be mounted. The GPS antennae are for the EFIS One and EFIS Lite and the little "finger" antenna is for the Zaon MRX.	Here it is with the glare shield in place. The MRX antenna has to protrude through the glare shield and I've centered it on the glare shield.	Here is an overview of the glare shield. Hopefully the MRX antenna won't be too bothersome. There will be multiple LED flood lights under the glare shield to light up the panel when needed.

Also added some slurry under the glare shield to support the sides of the shield and will drill it and the upper skin in assembly and add a nutplate to the skin. That way the glare shield will have four attachment points.

We got the windscreen permanently mounted on the airplane using a combination of screws and Sikaflex adhesive.


First we taped the outside of the canopy so we could match the tape on the inside.	We scuffed up the roll bar and fuselage.	We taped of the inside of the windscreen and scuffed it also - with scotchbrite.

Then we taped inside and outside where the windscreen will rest on the fuselage. A mistake we made was to not tape enough. We should have taped off EVERYTHING. We could have taped paper of the antennae and completely covered the roll bar. We got adhesive on the roll bar so now we have additional work later.	After scuffing the exposed areas, we used Sikaflex Cleaner to prep the attachment areas and waited 10 minutes. Next was the black primer.	The primer goes on easy and dries quickly. After the primer you wait 30 minutes before starting the adhesive.

We inserted all the screws just barely enough to slip into the grommets. The grommets create a 3/16" gap between the windscreen and the roll bar which is required for proper adhesion.	The adhesive was applied using a standard caulk gun. A good recommendation that I didn't follow would be to warm the Sikaflex cartridges before applying to make it flow easier. Or use a pneumatic caulk gun. This photo was taken after the tape was all removed.	It not a perfect job by any stretch, but it should be strong and we'll do some cleanup and touchup to make it look better.

I decided that if I'm going to make the "hat shelf" for the canopy that I need to get after it and get it done so we can move on to other things. So, today I jumped on it and made a mold and we laid fiberglass. That will be set tomorrow and we can move on with gluing on the sliding canopy.


In the Lowe's aviation department, I bought some 1/8" plywood (actually door veneer) and a particle board shelf. I took measurements and knew that I needed to bring the hat shelf forward of the cross tube on which the canopy slider is mounted by 0.9 inches. Also, the shelf needed to be 0.7 inches thick at the leading edge. The goal of this "shelf" is to block the reverse airflow that bothers rear seat riders and is common to RV-8s.	This photo is after the clamps in the left photo were removed, but you can see how the particle board was cut and the veneer rough cut to size. After the glue set I trimmed the excess wood and filed and sanded the piece smooth.	This is the mold after final sanding and shaping. My plan is to mold the fiberglass under the leading edge and use that lip to attach weatherstrip to stop the down-the-neck air on the RCP passenger. During cold weather or high altitude flight, the cold air coming in is uncomfortable and it is difficult to get enough warm air to the RCP for comfort.

Whenever I'm laying fiberglass I tape off everything I don't want the glass to stick to. In this case, I don't want it to stick to anything, so everything is taped with clear packing tape.	Even though formed and clamped, the mold did not want to sit down on the frame, so the tape was used to pull down the sides of the veneer.	An ugly shot, but it shows how the shelf will fit on the aft portion of the canopy frame.

We laid on four layers of S glass and E glass and topped it with peel ply. The peel ply is taped tight underneath to form the leading edge as desired.	We were running out of cloth so I had to piece some together on the second layer which left a long bump across the piece. I will sand it down smooth.	Another ugly shot, but it shows how the peal ply is taped to hold the cloth in place while curing. The sides and trailing edge don't need to be taped under because they will be cut away.

We removed the hat shelf from the canopy frame and trimmed it, refitted it to the canopy and poured in some slurry to create a "hold down" shape such that when the shelf is put into place, it will grab the canopy tube to hold itself in place.

	Right out of the mold, the shelf looked a little raggy, but it had formed well and looks suitable for use.
	Left I've trimmed it and refitted to the canopy frame after taping the frame. I built an aluminum dam and poured in some slurry. After curing, it will fit tight on the tubing to hold the shelf in place.

Pulled the shelf off the canopy frame and cleaned up both. Then added some more glass on the shelf so I can shape it the way I want. With the resin added to grab the tubing at the trailing edge, the shelf is heavier than I expected, so I ground off a lot of the resin to reduce weight. I next need to drill the attachment holes and figure out how to mount the weatherstripping. Then we're on to gluing on the slider canopy.

The original plan was to glue on the slider canopy today, but the temp didn't get as high as expected so we decided to postpone until tomorrow. Was just as well because the shelf needed more work and needed trimming. So added slurry and let it cure and sanded back down. Attached it to the frame using two #6 SS screws through the existing gussets.


We fully taped the frame with blue masking tape but not up to the adhesive line. Then we added white vinyl tape to the adhesive line. The idea is that the blue tape will keep the frame clean and the vinyl tape can be pulled off as soon as the adhesive skins over.	The canopy carrier is very handy to work on and move the canopy on.	Next we did the same taping on the plexiglas.

I forgot to take a photo, but we applied the Sika Cleaner and Sika Primer before mating the canopy to the frame. We clecoed and clamped it together with 3/16" rubber spacer in between. The rubber spacers are small and will remain imbedded in the adhesive.	It's easy to see the black primer painted on inside the canopy.	Then I crawled inside and applied the adhesive with a caulk gun. FYI, a pneumatic caulk gun does not work with the Sikaflex caulk tube. I bought one just for this job, but there is not sufficient seal for it to work.
	Left, after applying the adhesive to the top and bottom of the frame tubes, we made a fillet using a finger. The fillet is mostly smooth. To right is diagram from the plans. Notice the C-670 bushing that fits into the spacer and it all goes inside the roller. Well, don't make the mistake I did and leave out the bushing. It works, but is sloppy and we wondered for a long time why it was so sloppy. Today we discovered the error and unfortunately, it slightly affected our measurements and how the canopy fit - by about 1/16 inch.


And another little problem - with the skirt on and the canopy slid back, the skirt hits the empennage fairing ...	before the canopy reaches the aft end of the side rails and before the nylon block on the center slider reaches the aft end. Thus, once the skirt is on, the canopy cannot be put on or off without removing the empennage fairing - and maybe not even then.	It's easy to see that the canopy is not full aft - yet the skirt is stopped at the vertical stab. Hmmm. I'll send a note out on the internet to see what others have to say.

We split the skirt down the trailing edge and worked with the left and right halves. That made the work much easier and we have a lot of glass work to do on the trailing edge anyway. We trimmed the skirt front edge to match the skin below the windscreen and trimmed the bottom edge to match with the edge of the overlapping skin along the fuselage side. We drilled all of the rivet holes in the skirt and frame below the canopy - we're not going to put any rivets through the canopy.

More fitting of the canopy skirt. It does not want to lie flat around the back. So, we used a heat gun and made good improvement on the fit. Also sanded the inside to make them sit more flush on the fuselage. Where the skirt parts were originally put together, there is an area much thicker and stiffer than other portions which make shaping the skirt tough. Sanded those down to make them as thin as the rest of the glass.


The skirt does not fit well. We split it in the back which makes handling the skirt much easier.	The normal open position will stop just short of the empennage fairing.	If the canopy is allowed to slide all the way back, the handle will hit the bulkhead behind the aft seat. So, we'll add a stop to avoid that problem.

Okay - the secret to fitting Van's canopy skirt is grinding - the inside of the skirt - not the outside. Forget about working on the outside of the skirt for awhile and, instead, work on the inside. There are multiple fiberglass lap joints in the skirt that are the result of the manufacturing process. You need to grind them down until the surface is flat. Don't be bashful about removing material. Then use a heat gun to shape the fiberglass to fit the way you need. Use pieces of lumber - any size (I used 2x2s) - and cut 1.5" - 2" slots in the end grain to slip over the edges of the fiberglass to apply pressure while heating the skirt. Take your time and gradually shape the skirts. Mine is beginning to fit.

We spent another hour or more using the heat gun to tweak the edges of the skirt until we thought we had reached a point of diminishing returns. So, we decided to lay fiberglass under the skirt to fill the remaining gap. Also I'd decided I wanted to make the skirt profile on my RV match that of Hale's of Tulsa which fills in the "cutout" area at the lower aft portion. So, we added in some glass for that and also connected the two skirts back into one by putting glass across the split at the trailing edge.


It's easy to see the gap around the edge of the skirt. It seemed the best way to fill that gap was to fill it with fiberglass.	So, we cut 3 strips 6" x 36" for each side to fill the gap and extend the fiberglass skirt lower. We also added 3 layers of S glass across the split in the rear to reconnect the skirt sides.	Of course the fuselage was taped to prevent epoxy from sticking to it. We laid the glass on the inside of each skirt and then clecoed them to the canopy frame. Then we added some more the the outside and topped it with peal ply.

We popped off the skirt, trimmed it, and it still didn't fit as snug as I wanted. So, I decided to add some micro slurry under the edge of the skirt. I suspect there are two reasons the skirt didn't lay as flat as I wanted - the thickness of the tape used to protect the fuselage and the tendency for the original skirt to seek its normal position despite being taped down.

We smeared some mold release on the fuselage and added slurry under the edge of the skirt. Later I'll add some weatherstrip to help seal the bottom edge of the skirt. Also, added some slurry to fill low spots on the outside of the skirt.


The skirt after adding the glass under the trailing edges. I drew a pencil line on the fuselage tape for the cut line and it transferred to the glass.	The skirt after trimming. Notice the skirt no longer has the typical Van's curve to wrap around the fuselage. I cut a V in the trailing edge for the empennage fairing and we'll make the fit nice later.	The gap along the lower aft edge was still too great, so we added micro slurry to fill the gap. I'll sand it as necessary and continue to add micro to the top surface until it is smooth.

Sanded the skirt to shape and we have to do one more round of filling and sanding before using Sikaflex and CS 4-4 rivets to secure the it to the canopy frame. We added the slurry tonight and we'll sand and prime tomorrow before gluing the skirt on.


	Upper left - you can clearly see where I added fiberglass and slurry to create a curve on the skirt instead of the normal Van's cutout. Above - slurry was added to fill the area around the slider and fiberglass across the top to close the gap. Upper right - overview of the work. Left - The first of many vinyl tape layers to do the windscreen fiberglass. Right- we moved the plane out in the sun to cure the resin more quickly.

We resanded the skirt - put on more fiberglass - sanded some more - filled pinholes - sanded some more - primed - filled pinholes - sanded - and then, finally, glued the skirt to the canopy.

	Right - We had to add some glass to the left side of the skirt to make both sides symmetrical.

We added lots of slurry to fill pinholes.	We put vinyl tape along the canopy and the skirt where the Sikaflex adhesive was to go. That way we could make a small fillet, remove the tape and have a clean job.	You can't tell in this photo, but the gluing is done and the tape removed. We'll see how well we did tomorrow. We're going to rivet the lower skirt to the frame.

I decided to do the windscreen frame layup and then remove it, do the finish work, and reinstall it. The main advantage to that approach is not having to worry about scratching the canopy while sanding the glass. Normally, the major disadvantage would be a potential loss of strength. In my case, loss of strength is not an issue since the windscreen is already secured with both Sikaflex and screws.

	Left - Clecos are holding the skirt in place and initial taping is started. Right - All CS4-4 rivets are holding the skirt in place. Three shots below - taping is complete for laying the windscreen fiberglass. I used vinyl electrical tape to define the fiberglass edges.


Above - clear packing tape was used to keep resin out of the openings Below - Nelson and I are applying peel ply.	Above - across the top of the canopy I used three layers of two inch wide fiberglass tape along with two layers of carbon fiber. I should have cut the carbon on the bias because it tends to unravel more than fiberglass cloth. Below - peel ply was applied over all the glass.	Above - I added some black pigment to the resin mixture because several guys said they wished they had done that so the ugly inside of the fiberglass doesn't show. The peel ply will make a nicer finish and soak up excess resin. Below - we'll let it sit overnight and pop it off tomorrow.

The windscreen frame came loose easily and I trimmed it. Then I sanded down the high spots and added micro slurry to fill pinholes and other low spots.

I forgot to take a photo before trimming the frame, but got one after trimming and adding the slurry.

We sanded down the windscreen frame and put on more micro and then, late in the day, sanded it down again. We also sanded the canopy skirt.

Spent most of the day filling and sanding pinholes in the windscreen frame. It seemed like every time we filled some pinholes and sanded it flush, more pinholes appeared. We finally tackled all of them and attached the frame to the windscreen. We also filled and sanded the canopy skirt.

	Left - Fitted the frame several times in between filling and sanding. We drilled #40 holes (later opened to #30) and used clecos to hold the frame tight. Right - We removed the frame and primed the plexiglass and the inside of the frame. The plan was to adhere the frame to the canopy with Sikaflex and to the fuselage with fiberglass resin slurry and later add fiberglass to feather into the fuselage. The clecos allowed us to accurately reposition the frame each time and later we'll fill the holes with CS 4-4 pop rivets and glass over.

The windscreen frame was glued on using Sikaflex and fiberglass resin. The clecos worked well to hold the frame and the clamps across the top ensure no movement until everything cures.	A side view and ...	a front view with the frame installed.

We applied resin from the curve in the frame down to the bottom and Sikaflex above that.	The clecos were dipped in mold release before inserting them. The resin under the frame is easily seen and the Sikaflex oozed out along the top edge.	We'll do lots of finishing to make the frame look good.

We removed the clecos from the windscreen frame and sanded it down on the leading edges of the frame to almost flush so we could add fiberglass to blend into the fuselage. We pulled off the slider and taped it off for exterior primer. Then there will be more filling of pinholes and sanding.

After sanding the windscreen frame we riveted the cleco alignment holes and added two layers of glass to ease the abrupt leading edge of the frame and two more thin layers to cover it all. Tomorrow we'll sand it smooth and flush and start the pinhole filling. Hopefully the canopy will be essentially done by this time next week.

	The windscreen frame after yesterday's glue and resin attachment. The fit is very good and the adhesive edges are okay. We slid the canopy forward and it fit very good. Here we've added the rivets and put some resin on the frame and fuselage to prepare for the final layers of glass.
	The first two layers of glass were on the fuselage and butted up to the forward edge of the frame. They are to ease the step down from frame to fuselage. The next two layers were light cloth and covered from above the rivets down onto the fuselage so we can blend the transition.