Getting ready for the trailing edges...

[Av8torTom]

Finished everything on the empennage except the trailing edges. Anyone have any advice for a good result? I have Proseal and an aluminum angle to cleco onto each edge while the Proseal cures.

How long should I allow the Proseal to cure before I rivet?
Is back riveting the best technique?
Any thing else?

Thanks,

Tom

 

[larrynew]

How long should I allow the Proseal to cure before I rivet?

Definitely more than two days. I got in a hurry and had difficulty keeping it straight. If I do it again, at least a week.

 

[bruceh]

On my rudder trailing edge I let the Proseal set up for 3 days and it was fine. When you take the clecos out, hit the dimples on both sides lightly with a deburring tool to clean out any Proseal that will affect the fit of the rivet head in the holes.
Just work your way out from the center when you rivet and do every 5th rivet, then every 3rd and so on until there are no more holes left to fill.

 

[Av8torTom]

Back riveting?

Did you back rivet???

 

[cln1owner]

Did you back rivet???

Definately back rivet. It's been a while but IIRC the instructions describe a "half set" technique with the back rivet set, then a mushroom set to finish them up.

 

[PaulR]

Squeezer

I ground special sets to fit my squeezer and used them. The angle of the sets matched the elevator angle. I didn't have much confidence in shooting rivets back then and saw a thread with this suggetion.

Worked great for me.

 

[Greg Arehart]

Back riveting with a mushroom set is the way to go, unless you have some of the special ground squeezer sets. I alternated my rivet directions. If you are careful, this doesn't matter, but it is easy to overdrive the rivets and ultimately this may result in a curved trailing edge if all the rivets are (over)driven from the same side. I also started with every fifth rivet and then filled in. Hypothetically if you really overdrive every rivet while alternating sides, you would get a wavy trailing edge, but that is unlikely unless you're really beating up your trailing edge.

Bottom line is don't overdrive the rivets and you should be fine.

cheers,
greg

 

[N941WR]

Squeeze 'em

I detailed how I was able to squeeze all my trailing edges, which came out very straight.

Here's the link: http://www.repucci.com/bill/ailerons.html

 

[terrye]

squeezer and rivet gun

I used proseal, let cure for 2 days, then a standard pneumatic squeezer with standard dies. Squeezed about every fourth rivet so there was just clearance between the sqeezer die and the skin. Rivet was set far enough that it didn't fall out, then back riveted with a rivet gun. Trailing edge came out dead straight.

 

[lorne green]

Greg

Back riveting with a mushroom set is the way to go, unless you have some of the special ground squeezer sets. I alternated my rivet directions. If you are careful, this doesn't matter, but it is easy to overdrive the rivets and ultimately this may result in a curved trailing edge if all the rivets are (over)driven from the same side. I also started with every fifth rivet and then filled in. Hypothetically if you really overdrive every rivet while alternating sides, you would get a wavy trailing edge, but that is unlikely unless you're really beating up your trailing edge.

Bottom line is don't overdrive the rivets and you should be fine.

cheers,
greg

Spot on: This method worked well for me...months later the rudder fell off the bench. A little prang on the lower rudder trailing edge, but it worked worked out fine in the end.
Let's be carefull out there!!

 

[videobobk]

Bill R. has the right idea. Grind one rivet set so the the angle wedge will just fit and squeeze everything. Do mark that rivet set so that you can get it rotated perpendicular to the edge. If it is off by more than a few degrees it can dent the metal. And everyone is right; clean out the dimples, don't over drive, use proseal, and let it set longer than you think necessary. Not as hard as it seems!

Bob

 

[Pilottonny]

RTV

I did not want to order pro-seal from the USA just for doing the trailing edges, so I used a good quality RTV instead.

It is easier to use (one component and comes in a cartridge) and definately stronger, because pro-seal is not a glue it is just a sealer.

I over did some rivets but that did not do anything to the trailing edges, still dead straight.

Regards, Tonny.

 

[aerhed]

I hope the RTV doesn't "Richard" with you when you go to paint.

 

[N941WR]

I did not want to order pro-seal from the USA just for doing the trailing edges, so I used a good quality RTV instead.

It is easier to use (one component and comes in a cartridge) and definately stronger, because pro-seal is not a glue it is just a sealer.

I over did some rivets but that did not do anything to the trailing edges, still dead straight.

Regards, Tonny.

I hope the RTV doesn't "Richard" with you when you go to paint.

RTV has silicone in it and paint will not adhere to it, this it could very well bugger up your paint job. Buy the small tube of proseal and go that route.

 

[Pilottonny]

Who the #*(% is Richard?

I hope the RTV doesn't "Richard" with you when you go to paint.

Richard????

Anyway, no mine is painted and its perfect. It's not the silicone stuff...... never use that! I used the stuf that "seals and glues" and can be painted over ("Tec7" for example)

Regards, Tonny.

 

[KRviator]

Has anyone used T-88 adhesive for the trailing edges?

I'm sure I can remember some reference to it, but I've no idea where it was. Seems to me it might be a lot nicer than Prosealing things?

Annnndd...

"Richard" = d**k, so it's a polite way (albeit one I haven't heard of before) way of saying "I hope the RTV doesn't stuff you around"

 

[RVNineA]

Has anyone used T-88 adhesive for the trailing edges?

I'm sure I can remember some reference to it, but I've no idea where it was. Seems to me it might be a lot nicer than Prosealing things?

I used T-88, and it worked fine, but not on my first attempt.

My first attempt was just an experiment with some hardware store aluminum to see if that epoxy would work ok here. I made a sandwich out of two thin sheets and a 1/16" strip to simulate the actual trailing edge components. I drilled and countersunk a long row of holes so I could practice the riveting also. I lightly scuffed and cleaned the mating surfaces (Dawn and water, then acetone), applied the T-88, clecoed it, and waited a day or so. Soon after I started working with it, I managed to apply a slightly bending, or twisting to the assembly, and it split apart; the epoxy let go along a long stretch of the joint.

I tried again, except this time, I scuffed more heavily, then cleaned again. This time it held together very well. So I proceeded to use it on all of the tail components, using Van's method of backriveting, and had no trouble at all. All trailing edges came out very nicely.

(PS: this is ancient history, my memory may be a little fuzzy on some of the details)

(PS #2: I later built my flaps and ailerons without any adhesive in the trailing edge, and they also came out perfectly straight)

Happy Building!
John

 

[Av8torTom]

Prosealed everything

Prosealed all the trailing edges of the empennage and the trim tab ribs yesterday - man, that's messy stuff. Hopefully the angle aluminum used to hold everything straight won't be stuck to the skins when I pull the clecos in a few days.

Thanks all for your input...

 

[bruceh]

Just smear a thin coating of some vaseline on the angle. Proseal won't stick to petroleum jelly. Someone else here had that tip. Worked great for me.

 

[Av8torTom]

Worked very well...

I used a 3 or 4 inch no hole yoke to partially squeeze and set the rivets. Started in the middle, ends, then halved the distances. I flipped it over and squeezed in rivets from the other side same as first. Then I back riveted one side with a swivel mushroom head set, and repeated on other side. Went back and squeezed in additional rivets both sides and repeated back riveting until all was set. This way I didn't have to grind a special set of dies, and mess with rivet tape. Looks great!

 

[Sig600]

Off topic warning!

Anyone have any idea why Van's went from the one piece folded rudder skin, to the two piece that it is now?

 

[Av8torTom]

Not sure

but when the rudder was redesigned and enlarged they went to the two piece skin design. Sure makes back riveting those stiffeners a lot easier, and now that I've riveted the trailing edge that's a no brainer...

 

[Daver]

JB Weld

I used JB Weld on all my riveted trailing edges.

The turned out very good.

Dave
-9A flying

 

[dlomheim]

Split rudder trailing edge...

Off topic warning!

Anyone have any idea why Van's went from the one piece folded rudder skin, to the two piece that it is now?

Ten years ago I knew of a couple friends with RV-4's /6's that experienced cracks radiating out from rivets along the folded end; so when the "9A" came out I always assumed the change was an easy way to address that issue...

Doug Lomheim
90116

 

[Av8torTom]

Trailing edge update

Finished all the trailing edges. Pleased with the results that involved a combination of Proseal, squeezing rivets and back riveting flush with a swivel set. Hard to get a goodpic, but here are two of the rudder...

and one of the leading edge rolled and riveted: