HS / Elevator End Rib Fill Process

Hey Guys,
I've got about a months down time before my next kit arrives. While at OSH this past week, I noticed that several of you guys went above and beyond with glassing the tail (filling the HS / Elevator end ribs). I love the look! I'm wondering if someone would mind sharing their process, materials etc. If its not too time consuming, I may follow suite while I'm finishing up the tail glass work etc. this week.

I'm assuming its pretty simple process with a foam rib filler and 9oz glass over top & micro fill. How many plys, pics etc. would be awesome info. I'd like to get it right if I do go this route.

Thanks guys.

I'm not sayin' don't do it.....but please, you need to be very sure of the physical security of whatever you add in those end ribs. There is potential for a control jam.

Thanks Dan. That is one of those things that I was concerned about also... The way the way the counter weight bolts run on the newer -7s scares the poop out me. If those ever come loose, you're dead.

Daniel S. said:

Thanks Dan. That is one of those things that I was concerned about also... The way the way the counter weight bolts run on the newer -7s scares the poop out me. If those ever come loose, you're dead.

Click to expand...

They're safety-wired on my Air Tractor. For peace of mind, you can used drilled bolts and safety-wire them.

Best,

Hey Dan S.....I spoke with an OSH judge years ago, when that end rib filling was a bit of a trend at the time. He was absolutely adamant that he would never judge a sheet metal plane highly if that was done. Hey gave lots of personal thoughts about how a riveted sheet metal airplane should look, along with words like "elegant lines of rivets", etc. Also said: "if you like the look of a Glasair, then build a Glasair." It's been a while since that discussion, of course.

Doing it on the root end of the elevators introduces some balancing issues, although the bulk of any foam, balsa, and resin will be closer to the hinge line.

But, probably the biggest protest against the idea came from Van's themselves....they mentioned weight, but also water incursion and trapping. And that doesn't just mean exposure to a rain storm, it could mean the accumulation of condensation over a period of time, with nowhere for it to go since the relief holes in the rib corners are sealed.

Don't want to preach, but maybe ask yourself what you're trying to achieve, given the unknowns you'd be introducing.

FWIW, mileages, other usual dislaimers.

judge's agenda

Brad_in_Indy said:

Hey Dan S.....I spoke with an OSH judge years ago, when that end rib filling was a bit of a trend at the time. He was absolutely adamant that he would never judge a sheet metal plane highly if that was done. Hey gave lots of personal thoughts about how a riveted sheet metal airplane should look, along with words like "elegant lines of rivets", etc. Also said: "if you like the look of a Glasair, then build a Glasair." It's been a while since that discussion, of course.

Click to expand...

I know I am in the minority and not interested in having my plane "judged", mostly because of the closed minds of some judges. I would like to know how he would judge the RV-1. The wings have the rivets filled. The statement attributed to the judge - "if you want a Glasair, then build a Glasair", shows he can not be a fair judge. His opinion of what should be built by who is not part of the judges job.

I have helped build a Glasair and it was beautiful. I didn't want a Glasair. I am building a 9a, and I like the look of the rivets - all in a row looking clean. What I don't like is seeing the small indentions when light flows across the flat surface. I have seen some very beautiful RV's with excellent workmanship, and there are still indentations. I am making the wings, VS, HS, and rudder, smooth by filling them with either epoxy or lightweight filler. It does not take much. I used just over 1-3oz tube of glazing to fill the rudder, VS, and HS. It took several hours and lots of hand sanding, but I think it looks great - and I am the one who will judge my plane. I have taken extensive pictures of the rivets on all the surfaces in case I decided to sell the plane - the new owner would be assured I wasn't covering poor rivet quality.

I totally agree with Dan's concern of the plugs in the tips coming loose. Make VERY sure those have no chance of coming out with glue, epoxy, and mechanical methods. I am using an aluminum skin, riveted and epoxied in place.

I don't have any aspirations to have my plane judged. Judges with their own agenda, it wouldn't be worth it anyway. I also am not saying anyone else should fill over the rivets unless they want to. If the written rules for judging an RV say - rivets must be visible, great and the judge is right. I like the look of the rivets, but I like the look of a glass smooth wing better. The limited weight from the filler will easily be offset by less primer and paint buildup.

Build the plane you want - not the one some judge wants.

Only plug those pockets if you want to go fast

No one sees the unfilled rib pockets on a properly built horizontal stabilizer and elevator as an eyesore. Adding anything without a function or performance objective is not a good idea.

I filled mine for drag reduction and in the interface at the elevator counterbalance the difference in speed is significant. I believe I know why but the bottom line is I tested it and the difference on our RV-6A at 6,000 ft dalt is on the order of 3 kts which is much higher than I usually get from a mod. This is not an effective drag reducer on the wing locations (tips, flaps and ailerons) and after testing them I removed them.

Bob Axsom