Flap aileron trailing edge blind rivet selection

[Gary Wallace]

Has anyone used flush stainless blind rivets on ail and flap trailing edges and if so where are they available. Also, has anyone used same flush rivets on aileron nose ribs into counter weight tube? Thanks again

[jaredyates]

I was wanting to use flush rivets on the control surface trailing edges but couldn't find a way to dimple the trailing edge. I suppose one could make a custom die, but after they were submerged by the fabric layers, the regular rivets are barely visible.

[Gary Wallace]

Oh ya...I did think of the dimpling issue a bit ago but totally forgot about that. Thanks for the tip. I guess use the same rivets for the aileron counter weight tube I was thinkingnofnusing flush pop rivets in nose ribs elsewhere if no one thinks that would be a waste of time and effort?

[Battson]

Yes, I used flush stainless steel rivets. It looks great to start with...
Be sure to put a marine grade anti-corrosion compound between any steel and aluminium parts which will be in permanent contact. This goes double for stainless steel. It's so easy to do when you're building, and will ensure a long corrosion-free life for those parts.

[Gary Wallace]

Flush stainless steel riveting have been trying to source them but not having any luck. Any idea where I would find them???

[S Lathrop]

This will work to dimple the trailing edge: http://www.aircraftspruce.com/catalo...ickkey=3954221

[Battson]

Flush stainless steel riveting have been trying to source them but not having any luck. Any idea where I would find them???

Local hardware store.

To the question about dimpling - you can relieve the holes with a countersink, it works and the join is still very strong. Just watch for the dissimilar metal contact (thus my previous post about corrosion). Lots of people have walked into mine headfirst - rivets still hold!

[Bcone1381]

Help me understand Blind Rivet Selection.

I would think an Aluminum blind rivet would be the rivet of choice for attaching two aluminum parts, and SS rivet for attaching things with dissimilar metals like the steel balance tube. In the Patrol Plans, Bob specifies "SS Pop Rivets" for the Balance Tube attachment, and merely "Pop Rivets" for the Aileron Pocket Skin.

Thanks Battson for the reminder about dissimilar metal corrosion, and ways to mitigate it. With that mind, is it prudent or negligent to use SS Pop Rivets throughout if we observe corrosion mitigation strategies? What is the "Best Standardize Practice" for us to employ?

[spiffymafied]

Setting aside corrosion concerns, stainless steel materials are roughly 3x more dense than aluminum. The resulting weight would need to be considered.

Also consider shear strength; taken from a pretty good article (http://machinedesign.com/materials/c...d-other-metals).

"Shear strength, the maximum stress a material endures before it fractures, comes into play when components see off-axis forces. Shear strengths are not typically quoted for stainless steels because they are too low to have engineering value. 4130 alloy steel has shear strength around 11 ksi, lower than those for the aluminum alloys."

Changing to stainless steel hardware alone doesn't provide any additional corrosion protection aside from the actual piece of hardware. It is more likely to cause additional corrosion in the contacting materials than regular alloy steel. Looking at a galvanic series chart shows the substantial differential between stainless and aluminum.

[marcusofcotton]

Setting aside corrosion concerns, stainless steel materials are roughly 3x more dense than aluminum. The resulting weight would need to be considered.

Also consider shear strength; taken from a pretty good article (http://machinedesign.com/materials/c...d-other-metals).

"Shear strength, the maximum stress a material endures before it fractures, comes into play when components see off-axis forces. Shear strengths are not typically quoted for stainless steels because they are too low to have engineering value. 4130 alloy steel has shear strength around 11 ksi, lower than those for the aluminum alloys."

Changing to stainless steel hardware alone doesn't provide any additional corrosion protection aside from the actual piece of hardware. It is more likely to cause additional corrosion in the contacting materials than regular alloy steel. Looking at a galvanic series chart shows the substantial differential between stainless and aluminum.

X2. Wicks has AAC-42 aluminum rivets for flush (found online but not in their paper catalog) aluminum, CCC-44 stainless for lead filled balancd tube. Spruce has AAPQ-42 aluminum for protruding head aluminum riveting at much better price than Wicks.

[Bcone1381]

Thanks for the gouge, Marcus. I took your AAC-42 wicks rivet, Googled it, found an AAC-42 equivalent (Pop AK42ABS) and found them on Amazon for a very reasonable price.

[Battson]

Help me understand Blind Rivet Selection.

I would think an Aluminum blind rivet would be the rivet of choice for attaching two aluminum parts, and SS rivet for attaching things with dissimilar metals like the steel balance tube. In the Patrol Plans, Bob specifies "SS Pop Rivets" for the Balance Tube attachment, and merely "Pop Rivets" for the Aileron Pocket Skin.

Thanks Battson for the reminder about dissimilar metal corrosion, and ways to mitigate it. With that mind, is it prudent or negligent to use SS Pop Rivets throughout if we observe corrosion mitigation strategies? What is the "Best Standardize Practice" for us to employ?

@spiffymafied has the point - it's strength of the stainless steel rivets which is the determining factor in rivet choice.
If you choose aluminium rivets, and you can, then you want to ensure use at least four (max six) rivets at every rib-trailing edge joint. There is room to do that.

[haribole]

How does one rivet the counter weight tubes with pull rivets since these are filled with lead and 3/4" in dia ?

[JimParker256]

How does one rivet the counter weight tubes with pull rivets since these are filled with lead and 3/4" in dia ?

Which begs the question: How would you rivet them with driven rivets? (Not being a smart a$$, seriously curious about the technique.)

[Chris In Milwaukee]

I presume one would drill the hole the size of the unused rivet, and then when it's pulled, it will expand and hold everything together. That's the first thing that pops into my head. If I had to choose another method, it would probably be drill all the way through, countersink/dimple the hole, and then put a flat-head screw all the way through with a nyloc nut on the other side. But match-dimpling the tube could be interesting if it's filled with lead. Perhaps it's soft enough that it would work?

[Bcone1381]

Good Question! In the Patrol, each aileron nose rib has a circular cut-out. The balance tube slides into place thru these holes. Maybe the Pop Rivets only serve to keep it from sliding laterally. Maybe the SS pop rivets are able to expand and mushroom into the lead better than aluminum pop rivets.

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