[Bullseye]

Good morning, everyone.

After getting the rudder assembled and matchdrilled on Sunday, I got everything taken apart last night, and then started questioning when to install the fiberglass tips. I am planning on attaching most, if not all, of the fiberglass fairings with screws and nutplates, which will require dimpling/countersinking of the components.

Here?s the catch. Take the rudder bottom tip attach strips. If I disassemble, deburr, scuff, clean, prime, and rivet them back to the skin/bottom rib, I?ll be drilling through primed parts when I go to install the bottom fairing (and nutplates) later. Do people re-prime these parts (mainly the holes) after they are riveted to the already riveted rudder?

I?m thinking that maybe I should re-assemble everything, layout the spacing for the fastener attach points now, drill, and then go ahead and do the normal disassemble, debur, scuff, clean, prime, and rivet dance. I can get the holes drilled in the rudder bottom tip and attach strips now, isntead of after I prime.

What have other people done here?

 

[Mel]

Do not fit or drill the rudder bottom until you have it on the airplane. You may have to "raise" the lower fiberglass tip to clear the tailspring.

 

[Bullseye]

Ahh, now I see.

I read that step in the directions, and thought it would be a modification of the bottom forward part of the tip (and therefore, because I was attaching it with screws, would be no problem to attach now).

I now see that the whole thing will need to be, how do you say, re-inclined, to clear the spring.

I shall wait.

But that brings me back to to the re-priming question. What do builders to when they have to drill into a primed part. Deburr, (dimple, countersink if necessary) and spot prime?

 

[Rick6a]

.....What have other people done here?

Using screws and nutplates to make all the components removable, I completed all fiberglass work as I went. Later during final assembly, I did not experience any conflicting problems with fit including the tailspring.

 

[RV7ator]

Rivets swell up to fill the hole and thus exclude air/moisture that cause corrosion. It's exactly the same concept as crimp terminations. Priming is not necessary. If you don't buy that, what are you going to do about those thousands of unprimed/unpainted rivets?

Rick, I've got a question for you as I've considered making the rudder bottom cap removable on my 4th project. Can you remove/install the cap without the tail spring and fuse skins preventing extraction? It's well captured by these features, particularly since it would have to drop about 1 1/2 inches to clear the rudder yoke, and the tail spring clearly is in the way.

John Siebold

 

[noelf]

Hi Andrew...

...I see that you are working towards a 7 and not the 7A. On the -A's there is a great probability that the rudder bottom fiberglass tip will hit the Vertical Stab in the area where the lower attach bolts are located. This becomes a chore to deal with if the bottom tip is riveted in place.

As Mel has suggested, deal with this item once the vertical stab is on the airframe and you can see what needs to be "adjusted" to fit.

 

[Rick6a]

.......Can you remove/install the cap without the tail spring and fuse skins preventing extraction? It's well captured by these features, particularly since it would have to drop about 1 1/2 inches to clear the rudder yoke, and the tail spring clearly is in the way.....

John,

To answer your question, I really don't know. I have not had to remove the rudder bottom since final assembly. Worst case, I would think partial disconnection of the rudder assembly from the vertical stab should make short work of removing the rudder bottom.

 

[flion]

But that brings me back to to the re-priming question. What do builders to when they have to drill into a primed part. Deburr, (dimple, countersink if necessary) and spot prime?

Depends. Your exposure is small, and so are the risks. Since you will be installing nutplates, the screw holes themselves will get scuffed free of primer as you install/uninstall the fairing but you would not expect to get a lot of corrosion from such little exposure. As pointed out above, the rivets tend to fill the hole so no exposure to oxygen there (either airborne or waterborne). However, the truly anal (and I don't mean that in a bad way) will spot prime. I've heard of people using a Q-tip or toothpick to get primer into a drilled hole. Then there's the whole primer wars battlefield #1, do you need to prime at all? My -6 was completely primed (I expected to return to San Jose or vicinity when I started building) but my RV-10 will not have any alclad primed, so you can see that I'm impartial (yeah, right; well, at least I'm willing to weigh the pros and cons) when it comes to priming. I would say you hurt nothing by going either way; it's whatever makes you comfortable.

 

[Mel]

WHY?

I guess my big question is why do you feel that you need to make the rudder bottom removable?
I've had mine on for over 17 years and have never seen a need to remove it.

 

[L.Adamson]

I guess my big question is why do you feel that you need to make the rudder bottom removable?
I've had mine on for over 17 years and have never seen a need to remove it.

Mine is permanent too. The tail light is removeable by pulling the screws out. The nuts are fiberglassed in place. There is some slack in the light wire, which allows it to be unplugged.

L.Adamson -- RV6A

 

[Rick6a]

......why do you feel that you need to make the rudder bottom removable? I've had mine on for over 17 years and have never seen a need to remove it.

Mine is permanent too......

.......I've considered making the rudder bottom cap removable on my 4th project......

Why make things removable? I can't speak for others, but this choice, such as making all floors removable is a philosophy that traces its origins back to my production years. In that environment, I observed that no structure found on F-4s, F-15's, F/A18's, etc. is ever closed up permanently. Sooner or later, everything that can crack, break or corrode will see the light of day (or at least a flashlight) and blind rivets have no place in that design philosophy. Later, when I decided to build an airplane, that philosophy became part of my mindset, an expression of who I am as a builder. Thats all it is. Now as to practicality, well for me at least those choices have worked out very well and as anticipated. Item: A current thread describes a builder who wished he had a way to run wires underneath his floor, but the floors are already pop-riveted into place. For me the answer is plainly obvious. I too changed my mind during the course of the build and added or rerouted wires here and there on more than one occasion. Using a cordless screwdriver I have removed floors and reinstalled them in a lot less time than it would take to drill out and replace pop rivets some of which are sure to go back into oversized holes. Whether I choose to install a new wire run, install the latest whiz bang component, or even wipe up the remnants of a spilled Coke, I know I don't have to drill out a bunch of rivets.

As for making the fiberglass tips removable, one advantage is that it allowed me to fly my mostly polished RV around all I wanted until I calmed down long enough to remove and take home all the fiberglass parts for paint. I can report that during once such removable process, I discovered a sizable mud dauber home attached to the horizontal stab adjacent the forward tip. No way would that pile of mud been discovered if I chose to permanently pop rivet all that stuff on. And even if I did discover it....then what? Of course, good old pop rivets would have to be drilled out and the debris cleaned up. Screws are simply removed and reinstalled. If it happened to me, it is a virtual certainty mud daubers have found residence inside other RV's.

It all comes down to the personal choices we are free to make. I would no more have manual flaps as you would go electric. You would no more install screws and nutplates as I would use pop rivets. Seventeen years without removing things for a look/see is a very long time, still your personal experience validates your opinion. I get that. From my side of the street, I wanna know what has accumulated in there. I want to see essential structure from time to time with my own eyeballs, apparently other builders could care less. But I am really curious about John's response. John, now on your 4th project, you are now at least considering making the rudder bottom removable. May I ask why?

 

[L.Adamson]

I want to see that essential structure from time to time with my own eyeballs, apparently other builders could care less.

I could always pull out the tail light and look...

My wing tips are removable though. Same with the right seat floor pan.

L.Adamson --- RV6A

 

[RV7ator]

Good grief! This thread's still alive!

A reasonable question, Rick, since all others have been riveted in place.

The tail light/strobe requires a 20-some-odd inch service loop to pull it far enough from the cap to unplug/plug the connectors. Previously, I've bundled, tied, and secured the loop in the tail cone; I won't leave such a mess slopping around in the rudder or fuse. So the saddle fairing must therefore be removed for access.

I've had to pull the light fixture once. Then, painting after flying means taking the rudder off and also unplugging the connectors, then threading them back through the cap while holding the loose rudder, and then you reverse the process with a fishwire for reinstallation. Rather clumsy.

Since the fixed rudder cap is the root problem, I was thinking of making it removable rather than dragging some poor unsuspecting fairing into the fray.

John Siebold

 

[Bullseye]

I guess my big question is why do you feel that you need to make the rudder bottom removable?
I've had mine on for over 17 years and have never seen a need to remove it.

I think I fall somewhere closer to Rick's position here.

I've got the time, energy, and interest to make some if this stuff removable. Especially wingtips, some or all of the baggage floor pans, etc. For the rudder bottom tip, I figured that while pop-riveting the thing in place is feasible and very acceptable given the ability to pull wires through later, why close any metaphorical doors now? If I leave them removable, then I leave it open for easier inspection, repairs, replacement, etc. Unless one method is stronger, better, safer than the other, I'd rather have the flexibility.

For the priming thing, (don't want to start any further wars, here), I am somewhere in the middle of Flion's two methods. Anywhere where the alclad is untouched, I leave alone. I am priming ribs, stiffeners, anywhere I've fabricated something, and the mating surfaces on the skins. This way, I can't get too much grief from either extreme of the primer wars.

To John (RV7ator), I think I'm now comfortable with the "rivets swell up to fill the hole and thus exclude air/moisture that cause corrosion" explanation on the drilling after priming. (I would venture to guess, however, that my retentiveness will kick in in some places.) I will acknowledge the inconsistency between wanting to spot prime the drilled holes and leaving the unpainted/primed rivets alone.