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Tip-up Stiffener Retrofit?

dmat

Well Known Member
Advertiser
Hi gents,

I just acquired a RV6 tip-up but the canopy doesnt have stiffeners and it flops around more than I would like.

1) does anyone make a retrofit kit?
2) I know vans sells the stiffener but I would rather not have to drill and rivet as the paint is in good shape. Can I use structural grade adhesive to bond vans stiffeners to the canopy frame? Something like Hernon FusionBond.

Thanks,
D
 
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Before the metal stiffeners were developed, the tip-up canopy install instructions described/detailed stiffening the frame with the use of some bonded / shaped foam installed at the fwd most bow of the frame.

If you are willing to repaint on the inside, something like this could probably be done as a retrofit.
 
I chose the RV-7 stiffner kit. The RV-6 plans include a process and pics of using fiberglass to create a reinforcement. This, or similar approach, would seem the best route for a painted airplane
 
Thanks guys! , guess I will be ordering a 7 stiffener kit.

Dan
 
Thanks guys! , guess I will be ordering a 7 stiffener kit.

Dan

If you substituted NAS1097 rivets at the locations that would effect the outside finished paint, the manufactured heads are small and it would allow for very small machine countersinks in the skin.

I have a few of these on my own airplane where I added a ADHRS bracket in the tail cone after my airplane had been finish painted, and even with the rivet heads unpainted, they are hardly visible from 10 feet away.
 
Are the NAS1097 the shear-head pop rivets or solid?

Thanks,
D

They are solid rivets.
In simple terms they are the same as an AN426, but with a smaller head which allows for machine countersinking skins as thin as .025" thick.
 
Thanks! I need to call and place an order so I will ask for those as well. I assume I only need a hand full.
 
stiffners

Just purchased a RV6 last year. Curious what this stiffener looks like? Curious if we have one or not. Can somebody post a picture please. Thank you.
 
JMHO, if you don't know any better, a non-stiffened tip-up canopy is not all that bad. I was five years into ownership before I knew I had a 'flawed' (in another's words) canopy. I decided not to install the kit.
 
Hi gents,

I just acquired a RV6 tip-up but the canopy doesnt have stiffeners and it flops around more than I would like.

1) does anyone make a retrofit kit?
2) I know vans sells the stiffener but I would rather not have to drill and rivet as the paint is in good shape. Can I use structural grade adhesive to bond vans stiffeners to the canopy frame? Something like Hernon FusionBond.

Thanks,
D

One thing you could try is to install a weaker strut on the right side, and a firmer one on the left. If you do this, you must only open and close the canopy from the (left) firm side. A used strut works great on the right.

A side benefit is only needing to replace the left strut when it gets weak and move the weak one to the right side.

Never leave the canopy open unattended.
 
One good strut & one weaker one, not a good idea IMO.
Both struts will eventually wear, but not evenly going forward. When the stronger of the two finally gives out, the other one will be so degraded it wouldn't offer any resistance and the canopy will come down with a crash, bad results for plexi, fingers & possibly heads.
In the auto industry we were advised to never to sell one lift strut at a time.
 
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My 6a has Fiberglass stiffeners but the 6 I just purchased doesn’t have stiffeners at all and you can feel the difference and I can see cracks in places.

Do the stiffeners get riveted through the outside skin or just the dashboard/glare shield skin?

D
 
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One good strut & one weaker one, not a good idea IMO.
Both struts will eventually wear, but not evenly going forward. When the stronger of the two finally gives out, the other one will be so degraded it wouldn't offer any resistance and the canopy will come down with a crash, bad results for plexi, fingers & possibly heads.
In the auto industry we were advised to never to sell one lift strut at a time.

You should never run a strut to failure. Each time you lift the canopy, you are testing the strut. Each time you reach up and pull the canopy down, you are testing the strut. When the time comes that the canopy is not firmly held in place, you replace the left strut with new, and move the left to the right..... If you want new on the right, just buy a weaker one.

I have been doing extatically as I described in the above post for the last three strut replacements without any safety issues. The reason it works is because you are only pulling down from one side, and with a strong strut on the far side, the canopy will want to twist until you can overcome the holding power of the far strut....... This is not the same as closing the hatch on your SUV where you pull from the center and pay little attention to the condition of the struts until they finally give up. In that case, you should NEVER replace only one strut.
 
My 6a has Fiberglass stiffeners but the 6 I just purchased doesn’t have stiffeners at all and you can feel the difference and I can see cracks in places.

Do the stiffeners get riveted through the outside skin or just the dashboard/glare shield skin?

D

All are on the Tipper skin and many are outside of the windshield area, if I remember correctly. Some will also be under the fibergless transition work, though you can probably still get a lot of the benefits if those are left un-rivetted.

larry
 
Installing this stiffener in a completed aircraft would be a good contender for a quality adhesive.
 
JMHO, if you don't know any better, a non-stiffened tip-up canopy is not all that bad. I was five years into ownership before I knew I had a 'flawed' (in another's words) canopy. I decided not to install the kit.

FWIW, my non-stiffened tip-up was 18 years old when the (poorly) factory-welded brackets where the front rib section connects to the pivot arms failed on both sides. It seems pretty clear to me that the flexing over the years caused it, although the poor weld didn't help... It it had barely melted into the substrate, and essentially peeled apart. It wouldn't come apart in flight due to everything else around it, but you could see the gap at the front corners of the canopy while in the air.
 
Any suggestion on "quality adhesive"?

Some of the UV curing urethanes are quite strong. This is what your dentist uses to rebuild damaged teeth and they take A LOT of abuse. I used one to attach my targa strip. Also, the Gflex from West systems is supposedly pretty strong on aluminum adhesion, but suspect it may cure hard and I think this application may be better served by an adhesive with some flex to it.

Use caution, as many adhesives that work well on steel don't do nearly as well on aluminum; std west epoxy is a good example. Also, adhesive should go on within one hour of scuffing the aluminum, else the oxide layers degrades adhesion performance. I would use an aggressive grit and not just a scotch pad.

Some auto body panels are held on with structural adhesives and you will find some strong stuff from 3M and others in this area.

Larry
 
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Thanks! I will look into some different suppliers. I will also need to install a targa top on mine so I might be picking you brain on that one in the coming future.

D
 
FWIW, my non-stiffened tip-up was 18 years old when the (poorly) factory-welded brackets where the front rib section connects to the pivot arms failed on both sides. It seems pretty clear to me that the flexing over the years caused it, although the poor weld didn't help... It it had barely melted into the substrate, and essentially peeled apart. It wouldn't come apart in flight due to everything else around it, but you could see the gap at the front corners of the canopy while in the air.

Thanks for that insight, Rob. Looked over my welds today and they look pretty good. Except for the one that is missing. :( I'll put that check on my condition inspection checklist.
 
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