Okay, here's a question that I started to address in another post. Do you strip the covering from the center of the wing and glass the joint using fiberglass cloth or tape?
Is this an archaic practice that does not need to be done anymore, or is it still a viable practice that should be adhered to?
Do you new guys even know what I'm referring to?
C'mon give me some feedback here...
Thanks,
Bill

I'm ,(for the most part)a kit builder but I've assembled
several ARF's for myself and others.

I've never,nor ever seen anyone pull back the covering
to glass the wing joint. There might be several reasons
for this but I suspect for the most part it because :

1. it's not needed
or
2. it's too much like work which is why an ARF was
purchased in the first place.


Regards
Roby

I guess I am differant because I have never built an ARF OR kit without glassing the center section. I have also never had a wing fail either. I guess it is a matter of what makes you comfortable.

I also feel that it depends on how you learned your skills at ARF'ing or kit building and what manufacturer's kit you learned on. I built only Carl Goldberg when I started in RC in 1987 and all those kits have steps to glass the center section.

I guess old habits die hard.

CJ

Balsa Bandit,

Welcom to the "Dark Side" (Just kidding you, as I wrote on you previous ARf Comments)!

Yes, I always fiberglass my center sections, espeically if it's a model with the gear mounted in the wing!.

To the gentleman who said, that this defeats the purpose of an ARF, I disagree. I build ARF's because I have neither the time nor the time to build kits anymore (Kids, wife, dogs, grad school). ARF's for me are like a work in progress, they just need to be refined and tweaked. Do what you want, there are many ARF's out there without fiberglass center sections. You'll will also find there were a few ARF's on the makket, that experienced wing failures, which was solved when fiberglassed was applied.

Welcome to the Dark Side!

For what it's worth, here is my view on this subject...

I guess everyone has their own take on this as a result of individual experiences. I have had a wing failure - most likely due to my lack of flying skills at the time, however; ever since then, I not only glass the center section (on most but not all planes), I also replace the ply joiner with a solid piece of maple. It probably also depends on the plane and type of flying you are going to do. High wing loading and/or extreme types of flying should make you want to glass the center section. If you are not going to "wring it out" or if you are just into lazy scale flying then you may not want to go through the trouble.

Steve

I glass the joint if it is a kit, but not for an ARF. I had a GP Super Sportster .60 that was not designed to use a joiner on the spars, and relied on the wide (4 -6" wide?) 6 ounce glass joint for all its strength. It worked great. Other kits use relatively small wing joiners glued to front and back of spars, then add a 1" wide glass tape over the joint. Most ARFs are designed knowing that the majority of assemblers are NOT going to peel back the covering and glass the joint, so they are designed with long and strong joiners (OK, the good ones are, anyway!). Keep in mind that it takes a bit of work to fill and sand the area after glassing for a smooth surface to re-cover, and lots of ARF builders don't have covering tools.

Bandit, If it makes you feel more secure- do it. The worst that could happen is you add a little bit of weight to your plane.

I don't glass the center section of ARF wings. The most common argument for doing so is wing failures. Most ARF wings are pretty strong. A common cause of ARF wing failures is a lack of glue on the plywood joiner(s) and root ribs. Doing practice assemblies before actually gluing (so you know it will go together right), using a slow setting epoxy (30 minutes or more so it has a chance to soak into the wood and to give enough working time), and slathering plenty of epoxy on the root ribs, on the joiner, and in the joiner holes, will ensure that the center section is not going to fail.

The rule of thumb I follow is simple - If the instructions say to fiberglass, then I fiberglass. If they don't, I don't

The reason for this is that whoever designed it, engineered it to either need it, or not need it.

MinnFlyer - You hit it! I will f/g any single panel wing over 60", out to the saddle, unless it's designed with a tube. One less worry for 15 minutes work. And if the designer says use f/g, you otter.

Minn Flyer,

I can see your point! Like it was said before, it's a personal preference! However, I realize there is some "ENGINEERING" done, when you see that most of the newer ARF's are utilizing laser technology, therefore i'm assuming that there's a autocad program being utilize. Not wanting to get into a physics lessons, but I wonder if they manufaturers actually do any sort of structural analysis.

Minn, I'll also agree that most wing failures occour do to lack of glue. Does anyone remember a few years ago when H9 had there Edge 540 with all the wing failurs and there was some reported problems with the GP Lancair.

This is a good discussion, I'll probably continue to glass my wings, depending on the manufacture, their reputaiton and type of landing gear mounting if any and how I'm going fly the plane!

I put a little glass on top & bottom, both ARF & kit. Sometimes the ARF's show it, sometimes there's a belly pan that hides it. Here's why I do it.

A friend bought a stick type plane kitted in Illinois called the "Corvette." The kit was built, covered and flown by an experienced builder before he lost eyesight and sold all his stuff.

The friend proceeded to put about 150 flights on this plane, practicing pattern maneuvers & inverted flight, and learning to do rolling circles. One day he was doing rolling circles and a wing half fluttered away, leaving the plane to augur in. We found the parts and examined them on a picnic table at the field, and found no joiner. There was no spar element between the halves of the wing. The two halves had been butt-joined in the middle and 'glassed top & bottom. The wing held together all that time with nothing bracing it in the middle except that 2" strip of fiberglas, epoxied to the center.

I figure with a joiner, that plane would probably last longer than me!

Dave Olson

After ten years working at a hobby shop and seeing the wreckage, I do. But for every wrecked plane, I realize there are 20 others that are flying. I don't overdue it and don't add too much weight. I just try and bond the wing skins at the joint. Most of the forces in the wings we fly are actually in the wing sheeting for the most part. If the sheets are poorly bonded and come apart (the butt joint used commonly is not always the strongest), all of that force is funnelled into that little connector. I wouldn't trust that little connector with my life, or in this case my money. If the connector is made out of a strong material, the wing will break around the joiner. I saw a bunch of failures were the wing broke around the joint. I have also seen those ARTF trainers with the metal rod wing joiner having pulled through one of the panels. If a wing has a real strong reinforced joint, it will fail to the side of the joint. So you can over do it and add a lot of weight.

Is it always needed? No. Is a wing failure common? No. Could a certain plane benefit from it? Who knows until the wing has broken or the model is worn out and retired. Will I always glass my wings? Yes.

Are all joints designed to be strong? Yes. Are all designed never to fail under all circumstances? No, it would be far too expensive.

I just see every model an investment and take the extra time to reinforce it. But I think one should do as he feels. I do have to admit that I do have one plane without a glassed joint. It is a 30 size Cub with a Saito 30 on it.

My first low winger was an Andrews Trainermaster kit. I built it using silk and dope on the fuselage and the then new, to me, Super Monokote on the wing. On the thirteenth flight, I performed a Split-S at about 200' of altitude and watched my wing fold up alongside of the fuselage. A nearly brand new engine (OS.40-H), new Orbit 6-channel radio and new plane went into the ground at full speed. I was so shocked by the wing folding that I forgot to throttle back. I doubt if I had 125 flights on a multi-ship total under my belt at that time This was in 1970.

In one bad flight, I lost everything. Technically, I was out of R/C. Back then radios were extremely expensive. Getting up the money for a new rig set me back several months and that is when the wife and I were both earning good money working for Dupont.

Needless to say, after that I glassed every wing center section, regardless of the type of spars and joiners that were included. I also cursed Andrews for a long time afterwards.

Today, if the model (ARF) looks dubious as far as strength, I will either pass on it or I will modify it. After all of these years, I can pretty much tell what will hold up and what will not. I fly my models hard and I haven't had a wing failure since. ARF, kit or own design. Better safe than sorry.

I am coming to the conclusion that with all of the repair work and changes that have to be made to an ARF, I may as well design my own model and build it. If I was flying as hard and heavy as I used to, that is what I would do. Now, I will cherry-pick amongst the ARFs. I can usually find enough good ones to keep me flying. There are some good ones out there. What distresses me is that as soon as I give a particular model my seal of approval, they go out of production or they are changed by the manufacturer into not such a good model. I feel sorry for the young'uns that don't know what they are looking at.