Removing Canopy

I am at the point where I need to remove the newly fiberglassed canopy from the forward airframe. Per the plans, I left the two canopy struts installed during the fiberglassing process (next time, I'll remove the struts before fiberglassing!).

My question is: Has anyone come up with a good way to remove the canopy with the struts installed? If I remove the two forward canopy pivot bolts first, I fear that the struts' pressure might force the aft edge of the canopy hard against the rear window edge damaging it. Alternatively, perhaps I can lift the canopy open just enough (without scratching the forward fuselage top panel with the unfinished fiberglass forward canopy arms) to remove the aft struts' bolts?

Any useful tips will be appreciated!

The struts will push the canopy forward.

canopy

Remove the forward strut bolt first if the canopy is down. I broke both my struts removing the aft bolts first when the canopy was in the down position.

??? ??? Don't understand the problem exactly. Plans page and step? Isn't the fiberglass released from the skin forward of the canopy? Why not just raise the canopy fully, then detach the rear bolts of the struts first with no compression in them. (Takes two people for security.) Can't imagine disconnecting either end of the strut if it is under compression! Scratching the skin? Are you going to paint it? You have to scuff every square inch you paint with a scotchbrite pad!

THWACK!! That was the sound of my hand slapping my forehead. Thinking further about it, I realize that the struts will force the canopy forward (thanks for the reminder Mitch48041), so potentially damaging the rear edge of the canopy is not an issue. The canopy removal process now seem much less of a concern. However, I remain somewhat concerned about the canopy suddenly shifting forward during the forward pivot bolts removal and posssibly damaging the adjacent aluminum sheet. I guess I'll just get two husky helpers to steady the canopy frame and raise it as I remove the two pivot bolts. Wheee!!! Many thanks for your input!

ps -- I am on Page 34-16 / Step 1 "Remove the canopy".

Bill, the problem at that stage is that you cannot tip up the canopy yet without damaging the newly fiberglass skirt. This is after raw fiberglassing and before trimming the skirt to allow for free travel of the canopy. He just wants to remove the thing after finishing the glass job.
I had the same head-scratching moment, then decided to remove the pivot bolts while the thing was closed. The struts then push the canopy forward, expatend and can be removed without too much hassle. If you're worried about the rear window, remove it. It shouldn't be installed at this point anyway as you will need access to the aft cabin a lot before you can finally put the window in for good, that is likely to be on the day the DAR is scheduled to arrive.

Ahhhhh Dave - -

I'm guessing NOTHING will happen when you take the pivot bolts out. Actually, it takes quite a bit to get it freed from the panel top. Get a flexible blade putty knife under it and work your way around.

John Bender
410.6 hours as of this morning

JBPILOT said:

I'm guessing NOTHING will happen when you take the pivot bolts out. Actually, it takes quite a bit to get it freed from the panel top. Get a flexible blade putty knife under it and work your way around.

John Bender
410.6 hours as of this morning

Click to expand...

That was my experience exactly.

If the canopy is stuck in place, then there will not be pressure on the pivot bolts and they will not be damaged when removed, a good thing.
Joe Gores

I am about to start this process. After reading the chain I am confused. Am I better off to remove the struts before I start?

If I could do it over I would remove the struts before making the skirt.

Try using your air compressor. Adjust regulated air as high as it will go then direct air stream under fiberglass to try and loosen it. Worked on my 7 and 12.

Hi Ben, I finished the canopy fibreglassing & removed the canopy last week. I left the struts in place. When it comes to removing the completed canopy, it is only the small part of the fibreglass skirt FORWARD of the pivot bolt which may foul the aluminium. I loosened the pivot bolts a couple of threads so the canopy arms could move sideways a little if needed & with a helper raised the canopy slowly, keeping an eye on those forward pieces. There was a little scuffing of the 2 layers of tape, but no damage to the underlying aluminium. With the canopy raised fully, (and thus the struts extended fully), remove the aft strut bolts, then the pivot bolts & lift the canopy off. I had carefully applied boot/saddle wax to the plastic tape before applying fibreglass & found little problem getting the canopy to 'unstick'. A popsickle stick sanded to a flat point helped. Cheers, DEAN.

Before you apply the pre-resinated (new word?) fiberglass cloth and resin, try to imagine where that free-flowing resin will want to go and harden. It may end up flowing into nooks and crannies that will eventually impede your ability to easily remove the canopy after the resin has cured. Use masking tape and/or plastic tape to seal off any potential nooks and crannies. And go easy on the resin. Follow Van's directions, use Van's pre-resinated cloth and minimal resin to get a thin yet strong canopy skirt that requires minimal finish sanding. Enjoy!