Filling the 'smilies'?

I have noticed MANY RV's with the HS all smooth, and showing no signs of rivets. I must attribute this to the fact that the HS is the starting point that Van's recommends, and as new rivet-setters, I am sure many of us (including myself) are prone to the occasional OOOOOPS! As a first time builder, even though I have set thousands of rivets in my time (helping my grandfather years ago), I was a little bit rusty at first.

With this being said, what is THE filler of choice? Surely it can't be as simple as Bondo, or a similar product? I was speaking with the gentleman up at Jay Pratt's RV Central that helps with his prep and 'glass work (Troy, I believe), and he mentioned something special other than Bondo...For the life of me, I can't recall. Until I can get back over there and ask again, I thought I would throw the question out to the RV forum?

In my situation, I am not talking about completely filling anything. I just need to fill the occasional slip of the rivet set. Nothing major.

Any thoughts and/or suggestions?


Thanks in advance for any tips and/or advice!

Nobody????????????

I just wanted to 'revive' the post in case some people didn't see it the first time. Thanks!

I saw it but didn't respond becaue I have no interest in hiding the fact I'm building an airplane with rivets. I think it's cool. I have no interest in making my metal airplane look like a composite.

_I_ built my plane and along the way I made mistakes and learned a lot and I'm happy to show anyone where I made the mistakes and tell them what I learned. To me, it's all part of the experience of building.

Every rivet tells a story. So does every smilie.

Gary-

I was just at Arlington this weekend noticed what you have. It's surprising the number of RV's that have smoothed the horizontal stabilizers but no other rivets on the entire airplane. I would atribute this to one of two things: 1. they had the same difficulty with setting those HS nose rib rivets that a lot of people had and are trying to cover them up; or 2. They really just wanted a smooth finish, started to create one on the emp. and then just realized it wasn't worth the time on the rest of plane. I don't really care what there reason is, but agree with Bob that if you don't want rivets to show, build a composite plane. In fact, now every time I see any rivets that are filled over, I "wonder" what its "story" is.

On a related note, I've often stressed about any imperfections I've built into my plane. After going to the first airshow as a "discriminating" builder, however, I no longer have those fears. Some of the RVs there were of such a high quality I will never be able to match. On the other hand, some were old RV4s or 6s that had hundreds of hours on them that looked really beat up. Some were newer constructions that looked very "average." A couple of 9s had really wavy or bowed trailing edges and many had rivets that were not entirely flush. Even Van's RV-7A has rivets on the top leading edge of the wing that are not entirely flush. It definitley made me feel good to know that these planes don't have to be built perfectly to fly well. I still strive to build as best I can, but now stress out a little less about every rivet that doesn't sit perfectly flush. It makes me pretty certain that I can at least build a good "average-quality" RV.

Keep working... are you doing your elevator trailing edges yet?

Reading Comprehension

The guy's not asking about hiding the rivets, he's asking about fixing dings and smilies. There are several fillers available at Spruce for this, but I think in the end they're mostly just high quality lightweight bondo. Nothing wrong with smoothing out the mistakes.

Steve Zicree
RV4

Yes, my mistake. Sorry. I wish I were smarter and could read better but this damned old brain injury...

fixing smiles

If the guy was a fiberglass guy....He might have suggested Mirco or Flox..
Micro is epoxy with micro ballons mixed in to make a very light weight sandable filler
Flox is epory with Flocked cotton fibers added and is usually a structual filler that is not as easly sanded.
I can't comment on how well these products would bond to the alum in the small area around a rivet head or a smile......where a bondo type product made for metal work might be better.
just my .02 cents of info.
Bob Martin

Sorry, Gary, didn't mean to "hijack" your thread. Just focused on the first part of your thread because I know NOTHING about the second part. I'm sure I'll have one or two mistakes that I'll choose to "hide" too--most will just remain though to give my plane unique character and personality --so I would like to know what people recommend using.

So, back to Gary's original post, what ARE people using.

Don't use flox. It's very difficult to sand and not the right use of the material. Simply sand your smiles with some 240 grit sandpaper and cover the smiley with a mixture of microballons and epoxy. You should strive to make the micro as dry as possible.

Don't use Bondo or similiar polyester fillers. Most of the time it works okay, but it has a bad habit of cracking or separating from the aluminum. This usually happens in the most visible location, while that smiley fill on the bottom of the wing looks perfect 10 years later.

Thanks guys. The latest posts are correct: I am NOT wanting to hide the rivets; as a matter of fact, I think they add character to the plane, especially being flush (versus some of the production planes which use raised rivets). I don't want to hide that, especially after drilling, deburring, and dimpling every single one of them!

I was ONLY talking about filling in the occasional slip of the rivet set, nothing more. In my opinion, I am not building a plane to win awards, although I am highly particular about my workmanship. With that being said, if there is a 'smilie' a 1/2" from a rivet that could easily be filled, I see no reason not to fill it (easily done) rather than sticking out like a sore thumb. It's all just a matter of preference, at the end of the day. I was just wondering about the best method/material to fill one or two little areas.

Thanks for the replies.

I'm a fan of microbaloons and epoxy for filler. It seems to work well, and sticks to the aluminum good, too. We'll see how it looks in 10 years, but for now it's great, and other people say it will last just fine.

You can look at this page on my site and see some good pics of how it goes on there.. http://www.sadecki.net/rv/050612/ In the first pic, you can see how I prep the aluminum, by sanding the area that the micro will go on. In that pic the blind rivets already had 1 coat of micro applied and sanded off, and the low spots were getting a second. And in the last pic you can see the elevator counterbalance arm that had been filled an sanded 3 or 4 times by then. All the low spots and blind rivets were filled and it'll look perfect once painted.

I don't know how much more of this kind of work I'll do on the plane, but I had some spare time before my wing kit arrived, so I made it look nice. I'll definitely fill in all the blind rivets and little crevaces where the fiberglass parts attach, though. I think rivet lines look pretty cool on a plane, but blind rivets aren't so nice looking in my opinion, so their holes get filled with micro I've haven't had any nasty rivet gun accidents yet, but the micro would fill those nicely, too.

Filling dings

I asked a career body man and local EAA member what he recommended and he said they have a new two part filler for repairing dings on car bumpers. It bonded better then bondo, is flexible, and sands easily. FWIW

Bob MO

Super Fil

Spruce sells some stuff called Super Fil which is meant not to shrink. It comes in pink & blue tubs - I think it is epoxy based rather than polyester. I think is easier to use this stuff than mixing some micro - the balloons always seem to go everywhere. If you are filling dings the key is to rough up the surface well (120 or 80 grit might be suitable), and then alodine the surface as you've probably rubbed off the cladding - I find a "Touch'n'prep" stick really useful.

Pete

Super-Fil is made by Poly Fiber Inc. and is epoxy based. Make sure you mix it up well in the tub first because you can see the epoxy settle in bottom of the tubs. Some of us have used it, but on the long term, I can't say for sure.


You can get it from multiple sources, not just Spruce.

http://polyfiber.com/epoxy/

As far as hiding the rivets, I understand that some judges like to downgrade your score if the rivets are not visible. After all, an aluminum airplane should show rivet lines. I don't plan on having mine judged for the same reasons mentioned by Alpinelakespilot2000.