Wing Ribs & Covering
 

My wings are open bay. I've only done the bottoms, I used an iron on the perimeter (solid wood areas) and a heat gun to draw the open areas between the ribs tight.. Everything is drum-like tight , should I go back with the iron and tack to the ribs?

RE: Wing Ribs & Covering
 

I do - adds strength and reduces twist.

RE: Wing Ribs & Covering
 

I know that's what is important, but does it make them show.. I have it really tight, at least I think so? Like I said drum-like

RE: Wing Ribs & Covering
 

Failure to seal all solid surfaces to include ribs and any and all sheeting will cause the wrinkle sydrome and make your airplane look just like a prune everytime you are in the sun for a few hours and or whether conditions (humidity) changes.

Yes the rib or sheeting will show thats its job or part of it.

It has been more than once I have seen some fellows new ship (and not just new flyers either but older ones who should have known better too) Suddenly and catastrofically peel entire sheets of covering from a wing in flight. This is among other things one of the causes of this.

The ones I enjoy are when the wing blows up like a balloon changing the airfoil on one side only.

If you do not beleve me go ahead and finish your wing (you can always compete the sealing later. and twist comparing the same airplane of you buddy which is properly sealed. This factor is even more important with trainers and oldtimers (airplanes that is) Than with our newer aerobatic types and airplane with a much more robust wing.

Ok so you will know what will happen with an airplane that has inadaquate torsional stiffness you can actually experiance an aileron reversal. Now that will get your interest. This is something that a few very large glass full scale gliders have demonstrated and it makes for a rather strange handling glider.

This lack of torsional stiffness with your trainer that has not been properly sealed can cause you to suffer the same problem if you get into flight.

John

RE: Wing Ribs & Covering
 

I never do but it doesn't hurt to do it. When I pull the old covering to re-cover a plane it looks like the heat from the gun when shrinking tightens the covering onto the ribs because I have to peel it of the ribs too. To date I have never had the covering wrinkle up or act like a balloon. Whatever floats your boat.

RE: Wing Ribs & Covering
 

I generally like to cover both the top and bottom of a wing before doing any significant shrinking of the covering to avoid warping the less torizonal resistant stuctures. But I find that the weaker structures do stiffen up when the covering is ironed down completely to the underlying structure.

RE: Wing Ribs & Covering
 

I didn't mention it but I use Ultra as my base covering for all my planes and with the lower temp required that may be why my covering sticks to the ribs with just shrinking? During my years using mono I don't recall ever going over the ribs with an iron though.

RE: Wing Ribs & Covering
 

Before you do it do check for wing twist. If you plane calls for washout then make sure it's there or if not make sure it's flat. The shrinking job can pull significant twist into a wing if it's fairly flimsy to start with, and at this point you can still fix it fairly easily.

RE: Wing Ribs & Covering
 

Just for the record here was I said is its important to "seal all solid surfaces" It does not matter what method is used an iron or hot air. This is important with a lite trainer wing and even more important with the types that have no wing sheeting that forms a basic D tube such as a Senior Kadet, Seniorita and others. On these all torsional stiffness by design relies entirely on the covering skin. If one only seals the covering skin at the leading, trailing, tip and root edges then you have compromised the design intent of the structure.

John

RE: Wing Ribs & Covering
 

What John Buckner said.

RE: Wing Ribs & Covering
 

Got it now John, I iron down everything that is solid like the LE and TE sheeting, only thing I don't iron down is the ribs. Because I cover the wing and stab plus the ailerons and elevators in one sheet I have to iron down the complete TE sheeting or I couldn't do it. I also cure the covering in the hot sun before I add the trim but this time of year that doesn't work, Burrrrrrrrr, bring back summer!!!!

RE: Wing Ribs & Covering
 

If I read you right you shrunk before you covered both sides. [X(]  That can lead to your wings warping very badly.  Don't put any more heat on the covering until you get the tops on.
And I always seal the ribs before tightening.

RE: Wing Ribs & Covering
 

Yep... I was following these videos from right here on RCU... @ 6:40 of the 3 video he " Breaks out the heat gun" to shrink up a section that he has covered..?

www.rcuniverse.com/magazine/article_display.cfm
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RE: Wing Ribs & Covering
 

Mike Buzzeo definitely knew how to cover a plane, and the wing he was working on was not a flimsy frame. Even if you cover both sides first, you can not heat both sides at once when you shrink it, thus you have to progress around the wing in an orderly manner, which Mike does by starting with the panels closes to the wing root first. The possibility of warping exists no matter how you proceed if you shrink one area too tightly before the entire wing has been shrunk to some degree.