nippaero

nippaero

Well Known Member
I have a question on how to fill the rivets on the exterior of the airplane for a smooth glassy look. I have noticed several RV's over the years that have all the rivets filled and painted over. Some builders fill the tail while I have seen other planes where you can hardly spot a rivet on the whole plane. They almost look like a composite airplane. What is the process to fill in the rivets? Someone mentioned that you could use a filler/primer. What products are used? Does anyone have a good write up with some pictures? How much weight would it add to the airplane?
 
Mike, there might be a few small places where rivets or seams get covered (i.e. empennage tips), but overall - don't do it! You'll add weight and time. You're building an aluminum airplane, be proud of every rivet you set! :)

PS - Great avatar!
 
Just my 2 cents...I like the smooth look a little better. Yes, I'm still proud of the rivets I set, but I'll have the logs, pictures and data plate to say that I built it.

I would think that a smoother surface would allow for a slicker airplane. I wonder if that would be sufficient to overcome the weight penalty of the filler/primer.
 
If you fill just the rivet you'll still have a slight depression in the area around it. I'd say the depression is maybe an inch or so across and very shallow. To fill all of these to the point that the plane looks like a composite would add quite a bit of weight. I've seen em like that, and they do look slick, but I wonder about weight and longevity.
 
My concern would be, what happens if a rivet starts smokin? Seems to me that might cause the filler material to crack or pop.
 
I agree about the additional weight. I tend to fall into the build it light and simple philosophy. I am more interested in the how it is done vs. the weight/performance debate. The planes that I have seen had pretty elaborate paint jobs so maybe the paint shop did all the work willing and prepping the skins. There was a really nice guy up at Arlington this year. His plane was green with the card decks... The rivets were filled and it looked amazing.
 
Filling rivets

I have been thinking about this myself. Low airplane weight is my goal. I want to shoot one thin coat of primer, and then one coat of top paint. I was thinking of slightly thickening some PPG DPLF primer with flox or micro and then squeegee it on the rivets. Wipe the excess off with a rag and solvent. My goal is not to hide the rivets or make the indentation disappear. I only want to fill the circle (gap) around the rivet. I have read previous posts where people have applied multiple coats of primer and or topcoat to accomplish the same thing. With my method you wouldn?t see much, if any primer or filler around the rivets prior to the single primer coat. Only the gap around the rivet would have the material in it. I don?t think it would take that long to pre-fill all the rivet gaps.

Thoughts on this idea?

Sincerely,

Brian Vickers, RV4 finishing
Bainbridge Island, WA
 
Brian,
The problem with this method is that every rivet would be different. This would not be appealing. Either fill them completely or leave them alone.
If you fill them completely you will add much time and weight. I've done it. I would never do it again.
 
If you're dead set on doing it, what about some lightweight body filler, like Evercoat Rage Gold?
 
Aprox weight...

Met a guy at this years Arlington airshow. Green RV-8 with a gambling themed paint job, playing cards on the wing and some very nice airbrush work. He had everthing filled, very smooth, looked like a composite aircraft. Very beautiful job. For the life of me I can't remember his name, maybe someone here knows. Anyway, he mentioned that the paint job added 30lbs to the aircraft.
 
I like the smooth look myself especially with the composite top on the -10. I am leaning that way on my -10. If I do, I'll use a high fill primer on the rivet lines to conceal that then standard primer to finish. I have used high fill primers on boat hulls that are worked in terms of flexing much worse than aircraft and have not seen cracks etc. It is a risk though on any surface that can flex.

I have had good luck with Rage Metal Glaze. It should work better than the Rage gold for this application.

http://www.evercoat.com/productCategory.aspx?cat=1
 
I think good rivet lines are beautiful! Whenever I see a sheet metal airplane with all of the rivet lines filled, I always wonder if the builder did all of that filling to hide poor workmanship...

Just a thought.

Guy
 
one method is to take your filler-- Evercoat MetalGlaze or JB weld or ??? and mix up about a quarter-sized amount.

Quickly take a new razor and swipe a small amount across the rivet and then get the material just right on the razor blade and make another swipe from the opposite direction.

Then quickly clean your blade and then quickly clean up around the rivet so as to leave the least amount of extra material to orbital sand off later on.

that's one method. hope that helps. I know a couple more methods.

check out my photo dump InBox gallery for picts.
 
Guy Prevost said:
I think good rivet lines are beautiful! Whenever I see a sheet metal airplane with all of the rivet lines filled, I always wonder if the builder did all of that filling to hide poor workmanship...

Just a thought.

Guy
Click to expand...

That's one reason I have for keeping them...I have just a few "imperfections" other than that it looks pretty sweet. Maybe that's why we so many "filled" verticle stabs??
 
Regarding the green -8 with the playing cards, I saw it at OSH in 06 (it had just been painted). The first thing I thought of was, "how in the world is he ever going to fix a tank leak?".

He had filled in over the tank screws so they're no longer removable. That's going to be a bear when (not if) he gets a tank leak.

Also, if you're going to fill it, throw away the main wing skins you get from Van's and make yourself single pieces to eliminate the lap joint mid-span of the wing. Otherwise you're going to have a nasty 'hump' there.

Here are some pictures I took then:
2006-07-24.1630.jpeg
2006-07-24.1631.jpeg


To each his own on the filler thing. If I were going to build a smooth airplane, I would just build a glass one. I'm proud of my plane, rivets, screw-ups and all. Do whatever you need to do to be proud of yours.

But that's just my 2 cents.
 
cln1owner said:
Met a guy at this years Arlington airshow. Green RV-8 with a gambling themed paint job, playing cards on the wing and some very nice airbrush work. He had everthing filled, very smooth, looked like a composite aircraft. Very beautiful job. For the life of me I can't remember his name, maybe someone here knows. Anyway, he mentioned that the paint job added 30lbs to the aircraft.
Click to expand...

I don't recall his name either, but I did drool next to his plane for a while. He had some neat stuff going on. I think he said the paint took 18 months!

NWEAA07007.jpg


NWEAA07008.jpg
 
A buddy at my airport is an auto body and paint man and I got his opinion on preping and priming my fiberglass parts. One thing led to another, and he spent several days with me getting it done. He used the Evercoat metal glaze to fix the smaller imperfections on these parts as well as on the fiberglass around the windscreen. This product is NOT suitable for filling anything very large or deep - you would need a Bondo equivalent first for those - but it works great on small imperfections and rivets. In the course of doing the area around the windscreen we noted that a few rivets had been covered over and debated about whether to fill any more. Finally decided to do them all on the forward top skin, to make a nice match with the cowling.

This guy was an artist with the putty and a squeegy. It would be a lot of work to do it on the whole plane, but man, it sure looks nice where it is done on mine. Mine is primed now and it looks a perfectly molded piece of plastic. I finally have something to show off.

erich
 
I wouldn't bother - it's supposed to look that way!

There is an old story - probably apocryphal - about the need to increase production of Spitfires during WW2. It was noted that installing flush rivets slowed down production but that they certiainly improved the performance of the aeroplane, but by how much and where were they effective, and where not? The Air Ministry devised an experiment where they glued dried split peas to the rivet heads of a flush riveted Spitfire and measured it's speed. They then started knocking of the peas in rows starting at the front of the plane and noting the change in top speed as each row was removed. They then determined how far back along the fuselage they had to go before removing the peas had no effect on speed - presumably because the airflow along the fuselage became turbulent at that point. From then on Spitfires had mushroom head rivets installed beyond that point on the fuselage, thus enabling more to be produced - and the free world to be saved.

The point being "form follows function" especially when applied to Spitfires - or RVs:)

Jim Sharkey
 
hydroguy2 said:
I don't recall his name either,
Click to expand...

Michael Quatacker of Porterville, CA. Took second place at Copperstate in '06.

I think it was certainly the talk of the RV corral at Oshkosh in '06 but he didn't get an award in the competition, although he did get a plaque for "outstanding workmanship."

He did get custom built champion at Arlington this year, though.

Still, I remember thinking... all that time, all that money... and all that work. And no award at Oshkosh? That's clear a "show plane," and it had to be a disappointment not to get "the big one."

It's all I can do to get my plane built to be airworthy, let alone to impress anyone. I'm such a rube.
 
To Each His Own,

But an Outstanding Workmanship Award means much more to me than a Grand Champion Award.
 
jsharkey said:
There is an old story - probably apocryphal - about the need to increase production of Spitfires during WW2. It was noted that installing flush rivets slowed down production but that they certiainly improved the performance of the aeroplane, but by how much and where were they effective, and where not? The Air Ministry devised an experiment where they glued dried split peas to the rivet heads of a flush riveted Spitfire and measured it's speed. They then started knocking of the peas in rows starting at the front of the plane and noting the change in top speed as each row was removed. They then determined how far back along the fuselage they had to go before removing the peas had no effect on speed - presumably because the airflow along the fuselage became turbulent at that point. From then on Spitfires had mushroom head rivets installed beyond that point on the fuselage, thus enabling more to be produced - and the free world to be saved.
Click to expand...

That's a cool story...I wonder if it's true. If so, I'd love to see the data they collected from the experiment.
 
Just a thought............What if, by chance you have a "fender-bender" while taxing or whatever????? Drilling out the rivets neatly to salvage any understructure and to do your own repair, may be very difficult.
 
Mel said:
But an Outstanding Workmanship Award means much more to me than a Grand Champion Award.
Click to expand...

True, I suppose (I haven't thought that much about them since the moment I set my first rivet). It's just that there's a bunch of outstanding workmanship award, but only one in a competitive category. I don't see how you spent that much time on that goregeous plane without thinking about the big award at Oshkosh. But, like I said, I wouldn't know.
 
While I can see the reasons to do it and the reasons not to do it, I opted
to do it on my empennage and tops of the wings, flaps, ailerons and all pop rivets.

Here's the process I learned from the guy doing my paint prep
on my plane now.

Sand rivet line with 120 grit using just one or two fingers width paying
more attention to the rivet heads than the spaces in between.

Clean sanded area with comet and water until water no longer beads up
and then dry.

Spot dab each rivet with a semi-wet mixture of epoxy and microballons
using a small 1/2 inch flexible applicator.

Let dry.

Sand rivet line by hand until most of the epoxy/microballoon mixture is gone.

Clean surface.

Fill rivet line with a smooth line of your favorite green bondo, let dry,
and sand smooth with 220 grit.

At this point you should only see a light film of epoxy/bondo around the
edges of the rivets and low spots.

Clean surface and spray a self-etching primer over rivet line with 1/2 inch
overspray on each side.

Sand rivet line with 220 using hand sander until you see aluminum and just
a bit of the primer/bondy/primer around the rivet heads and low spots.

Clean entire surface of wing again and spray same primer over entire
surface.

Sand with 300 grit prior to painting.

You can't see the rivet lines after this. It's pretty time consuming, and
the looks is beautiful.

Many ways of doing this I'm sure. This is simply how we're doing it.
Hopefully I didn't leave any steps out.
 
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