Conference vmszoo::rc

    Try heating it with a gun or iron and then while applying heat stretch
    the covering over the wing tip.
    
    					Tom

    I tack the edges first and then apply heat to the gross wrinkles
    with a head gun.  They will come out!  I have built several wings
    with that wing tip design with good results.  It looks awful until
    you shrink it with the heat gun.  It takes a fairly high temperature
    to really shrink monocote properly.  Be careful not to melt it -
    keep the gun moving.  Also, I found that it really helps to vent
    all compartments including wing tips when you cover a wing with
    plastic films.  Punch a small hole with a drill bit in every rib
    and allow the wing to breath through the aileron servo hole.  Now
    when you heat the film, the hot expanding air has a way to escape
    and the wing will not blow up like a baloon.  This also helps keep
    the wing from blowing up in a hot car which stretches the film and
    causes wrinkles when it cools off again.  I failed to do this on
    my first wing and it puffed up like a baloon when I heated the second
    side covering.
    

    re .1  I have tried this, but I always seem to get ridges as I pull.
    Am I pulling too hard??  In which direction should I pull??  
    
    re .2 No, the wrinkles I am getting won't come out.  I can't seem
    to avoid having the wrinkles turn into folds...  Yes, the ribs are
    ventilated...
    
    Thanks!
    jeff
    

    Jeff,
    
    I'm definitely NOT an expert on plastic films but I think I know
    where yer' missing the boat.
    
    The object is NOT to pre-"shrink" the film but, rather, to use heat
    to "stretch" it over the compound surface, thereby removing the
    wrinkles...you should actually end up with MORE material than you
    started with.  You have to work a small area at a time, sometimes
    going back and lifting sections (with heat) you've already done `til
    you finally make it all around the tip. Naturally, you can only
    stretch ANY material just so far and you CAN tear it, so work slowly
    and carefully, playing the heat gun on the film while yer' pulling
    it out, then down over the tip...it ain't real easy but, with patience,
    you'll get a perfect job.  Lemme' know how ya' make out.
    
    Adios,	Al

    Are you sure that you are getting it hot enough?  Experiment on
    some scrap and take it to the melting point.  You should be able
    to get the folds and wrinkles out if you get it hot enough and pull.
    
    By the way, I am just about to cover my SS40 wing with Ultracote.
    I will let you know how I make out.  I have the fuse done already.
    The Ultracote seems to behave slightly different than monocote,
    so I am learning over again how to cover.  One good feature is it
    seems to be much less suceptable to bubbles when going over sheeted
    surfaces like the fuse sides.  The ads claim that the adhesive does
    not gas when heated.  I always thought that the problem with monocote
    was caused by air in the balsa being heated and expanding.  The
    results I got on the fuse suggest that their claim is valid.  No
    bubbles.  The other difference I have noticed is that the adhesive
    can be activated at a much lower temperature than when shrinkage
    begins.  This makes tacking the stuff to itself easier.  I am going
    to experiment with adding trim pieces over solid sections.
    
    I previously built and am still flying a SS20 with super coverite
    covering and Dope.  TOO MUCH WORK for a sport plane.  Repair of
    hanger rash and dings is a bitch.

    Jeff,
    
    I built the ss 40 two years ago, and am still flying it.  I can't
    imagine what the problem is with the covering but... when I covered
    the wings I first tacted down the entire leading edge end then stretched
    the covering across the wing and tacked it on the trailing edge.
    It should almost look as if it dosn't need any heat at all, that
    is across the wing itself.  Now tact the film in the center section
    and proceed to pull the film over the wing tip and tack it there as
    well. The tip may take aditional heating and stretching later, so
    DON'T cut off your handle(extra film).  Once again, at this stage
    the film should look pretty tight.  Now, with your iron, iron down
    all the sheeted sections.  If you come across a wrinkle, don't work
    it with the iron, its much easier to do so with the heat gun.  Now,
    use the gun to heat the open sections of the wing and if necessary,
    use your 'handles' to pull the covering extra tight.  When you are
    done, and the covering is to your satisfaction, trim the edges.
    
    Good luck jeff.  I have over 100 flights on me ss 40, and it still
    looks great.  Did you ever solve your engine problem??? I use the
    O.S. Max 45 ABC w/ a tuned pipe and a ten oz tank.  It's VERY hot
    and fast.  The ss has very little drag, and you will find it really
    moves along.  If you can get a good 40, I'd say thats plenty.  I
    couldn't get more then the ten oz tank in, and that gives me one
    pass over the stip after a nine minute flight!!!  I'd like to have
    a little more juice.
    Well, I'm sure you'll have fun w/yours... if it's your first or
    second ship, make SURE you get some help at the field.  If you build
    anthing like me, I'm sure you put many hours in at the bench,
    especially on the nose.
    
    Enjoy,
    
    Brian

    Yeah, the nose is a real bear on the SS-40...
    
    Well, it turns out that I was not using enough heat.  I started
    using gloves which helped a lot.  I also found an interesting thing..
    I have a Royal brand heat gun.  On a test piece of monokote, I could
    not melt the covering, No matter how long I held it there.  My monokote
    iron does get hot enough to melt it though...
    
    So, with gloves on and no fear of melting, I heated the covering
    much more and it went on like a champ.  
    
    Thanks all for your help!!
    
    jeff
    

    You found my technique, Jeff. If you're not burning your fingers,
    you're not getting it hot enough. I use a piece of cloth wrapped
    around my thumb so I can pull on it very close to where I'm heating
    with the gun. I also agree about leaving plenty of "handle", you
    need several inches. Pull slowly and hard while applying heat.
    
    Dave