Flaperon rivets missing

[Paul Z]

I've had this happen on my Kitfox SLSA it was on the right flaperon. It did start separating. I sanded re-epoxied and had to go with a rounded head rivit wher the rivit pulled out. I added two additional digits on doth sides of the rivit that pulled out. On preflight a, I now inspect between each of the rivets to check for delamination. When I was flying out to the 2015 Kitfox Factory Flyin I noticed it while unpacking in Abilene, Texas. I got socked in in Abilene with fog, I did a temp fix and when the weather cleared I flew home.

[HighWing]

I believe Kitfox uses the 9460 - should be in their parts catalog page 28

I hope this doesn't result in a debate, and I have no personal experience with the 9460, but do have experience with the "Structural adhesive" shipped for wing assembly in the early Kitfoxes. My opinion is that the 9460 is application specific - meaning with a thick consistency appropriate for building a fillet on the ribs as the wing is being assembled.

I have used the 9430 for many years - available at Aircraft Spruce. It has a honey like consistency and is excellent for bonding thin materials face to face. That would be my choice. It has no fillers that, also in my opinion, would tend to result in cracks in the adhesive. If it were my airplane, I would use the 9430 but with a thorough preparation of the mating surfaces - lots of careful going over with something like 300 grit sandpaper. rinsing with Acetone, then more sanding.

[Paul Z]

If the rivets keep popping out the results could be catastrophic. I ubmitted a safety write up to John.

[Northof49]

If the holes are sloppy , you can drill them up to a 1/8
And dimple the hole . Then put a Ad 426 -4 solid rivet back in.
.016 is to thin to counter sink it knife edges .
1/8 dimple dies at AC spruce $24.
Mike

[jmodguy]

While you are "out and about" a roll of gorilla tape can come in pretty handy...

[GMKman]

I definitely second the duct tape idea!!
It kept my last plane (Glastar td) in tact a few times in a pinch.
After doing much research and listening to the comments here, I'm thinking about using this stuff for the epoxy aspect of this repair.
Has anyone used this and if so, what's your thoughts?
From what I've read, the only two things that will withstand a nuclear blast is cockroaches and the two pieces of aluminum I bond together with this stuff.
Brad..

[jiott]

I would personally stick with the Hysol 9460. Don't think you can beat it, other than what Highwing says maybe the same stuff but different consistency.

[dholly]

A bit late to the party but IMHO... G-Flex would be appropriate for this purpose, and maybe more so than either Hysol due to it's modulus of elasticity properties. I used it for bonding dissimilar materials (Plexi to aluminum) and my testing showed very tenacious results. While there is no need for the ability to withstand expansion/contraction of dissimilar substrates in this instance, there is flexing of the flaperon skins in flight and perhaps some elasticity under both tensile and shear stress in this application would be a good thing.

From West Systems:

650-8 G/flex Toughened Epoxy

A toughened, versatile, liquid epoxy for permanent waterproof bonding of fiberglass, ceramics, metals, plastics, damp and difficult-to-bond woods. With a modulus of elasticity of 150,000 PSI, it is a bit more flexible than standard epoxies and polyester, but much stiffer than adhesive sealants. This gives G/flex 650 the ability to make structural bonds that can absorb the stress of expansion, contraction, shock, and vibration. It is ideal for bonding dissimilar materials. It can be modified with West System fillers and additives, and used to wet-out fiberglass tapes and fabrics. Mixed at a 1:1 ratio, G/flex 650 gives you 45 minutes of working time at 72°F. It reaches an initial cure in 7 to 10 hrs and full cure in 24 hrs. (8 fl. oz. / 236 mL)

[GMKman]

Thanks for the responses. I agree and think the gflex will be what I use as I can peel the existing epoxy off with just my fingernail.

[jrevens]

I agree that the G-Flex sounds like it might be a good choice for this issue. The fact that you can peel the old stuff off with your fingernail points to probable improper preparation of the mating surfaces before bonding.