Conference vmszoo::rc

    Mike,
    
    I can go into detail, if yo like, on the older "silk `n dope"  
    methods but, unless that's what yer' lookin' fer', there're far
    easier and, to my mind, better methods available today.
          
    One of the easiest/best is the use of either silkspun or super 
    Coverite.  Coose whichever best suits yer' application:  the silk-
    spun is a paper-like material composed of some sort of synthetic
    fibers, is lightweight, self adhesive (with heat) and tougher'n
    a boot;  super Coverite is a woven fabric (like silk, silron, etc.)
    which is even stronger but is also heavier.
    
    Whichever you opt to use, the application is essentially the same,
    i.e. iron it on (similar to the film-type coverings) and shrink.
    As with the films, applying it over a coat of Balsa-rite enhances
    the adhesion and promotes a better, more permanent job.
    
    Once in place, simply apply K&B (or similar) primer, sprayed, if
    possible, to minimize the sanding task (brushing works OK too) over
    the entire structure, even open wing structure.  As with glass,
    sand virtually all the primer off, taking care not to sand through
    the covering, especially in the open structure areas.  A max of
    two primer coats should do it.  You may kind it helpful to brush
    primer over the overlaps so these can be feathered into the sur-
    rounding areas.
    
    From here on out, merely undercoat and paint as you would for any
    other method.  One caution:  I'm not sure about the silk-spun, but
    with super Coverite, the shrinkage under heat is almost unlimited
    so seams/overlaps should be sealed with a bead of CYA to prevent
    the covering from shrinking clear away from a joint/overlap.  Other
    than this, the stuff is pretty straightforward to use and a good
    job should be readily achievable, even on the first use of it.
    
    If yer' wondering "where did we use the clear dope?" We didn't...
    it's not necessary (it tautens with heat) and, as a matter of fact,
    dopes generally don't work well with Coverite anyway, so just proceed
    straight to primer after the material ia applied.
    
    I'll be interested in variations on this method (or different methods
    entirely) but I've found this technique to be entirely satisfactory.
    
    Adios amigo,	Al

    
    	Al,
    
    		Thanx. How about using Super Coverite on wing tips ?
    	Should I do them as part of the wing top and bottom and overlap
    	on the underside of the wing, as I have done with plastic or
    	should I start with the wing tip as one piece and overlap the
    	top and bottom of the wing up to the tip?
    		I suspect the the first is the way to go, but it can't
    	hurt to get another opinion.
    
    				Mike
    

    Mike,
    	When I covered my SS-20 with Super Coverite, I did the wings
    with one piece top and bottom each side.  The Super Coverite shrinks
    like a B******!  It is easy to avoid wrinkles at the tips.  If you
    get the seams too hot, they will fray and the glue will get on the
    iron.  Wipe the iron off on a cloth if any adhesive gets on it.
    You can also wipe off any adhesive that comes through and gets on the
    top surface with thinner.  I had adhesion problems with dope over
    coverite.  Maybe the primer/epoxy paints will work better.
    Let me know how you make out with it.
    
    			Charlie
    

    Mike,
    
    As Charlie has said, Super Coverite can be made to conform to nearly
    any shape/curvature with proper application of heat and a little
    stretching/pulling.  As Charlie cautions, don't overheat the material
    and KEEP THE SOLE-PLATE OF YER' IRON **CLEAN**!  DO clean up any
    places where the adhesive has gotten on the surface as it glazes
    into a hard film that is difficult to cover/hide/feather-in when
    you prepare for finishing.
    
    As Charlie and I have both mentioned, dope doesn't seem to work
    very well directly over the coverite but applying color dope over
    K&B primer prepared Coverite works just fine.  In fact, once the
    finish base is established with K&B primer, you can use any type
    of paint you wish, i.e. dope, acrylic lacquer or enamel, epoxy,
    polyurethane (Formula-U, R.S. Perfect (Chevron), ad infinitum.
    As I've said in previous notes, I prefer Ditzler automotive acrylic
    lacquer with a plasticizer (from Southern R/C Products), but the
    choice is up to you...it'll all go over K&B primer just fine!
    
    Adios,	Al

I've been experimenting with a "new" material on this 1/2A wing
I'm doing.  Its a very silk-like material, called interfacing,
basically the dress lining material that you hear about once in a
while.  I understand that it is similar to Coverrite, but I've
never used the latter, so I don't know.

The lining material is a dream to use.  I have lots of experience
with paper, such as tissue and silkspan, and I've got to say,
this stuff beats them all for ease of handling.  I applied it
just like silkspan.  First the surface is given 2 coats of
nitrate dope, full strength.  Then the material is cut and laid
over the surface, and 50% dope is applied through the weave.
This is where the stuff is great; it soaks through almost
immediately, and sticks hard.  It is very easy to get a nice
looking wing, though I've had problems with a tiny wave-like
wrinkle appearing in one corner or the other of the trailing
edge.  A little application of the monokote iron at normal heat
takes it right out, and tightens the stuff beautifully.

The material trims with a sharp razor blade.  When you dope it,
slop a little on the material where you want to cut it.  This
stiffens it and makes it easier to cut.

I've just started doping it.  I gave it one coat of full-strength
nitrate to seal the weave.  It works great.  Next I will airbrush
a coat or two of 50% nitrate and a little silver Floquil (thanks,
Al).  The next two or so finishing coats will be 50% butyrate.

I believe this material is the equal of heavy silkspan in weight,
and is far stronger.  I plan to use it on larger planes, such as
when I recover my Eaglet.

The lining is about $2.98 a yard.  Wash it before using to take
out the sizing.   I also bought another material, one used to
make the lining of collars.  This backing stiffens the collar. It
looks like silkspan, in that it doesn't have a definite weave
like the lining material.  It was only .99 a yard.  I haven't
tried it yet, but would've used it on the 1/2A model except that
I wanted to try the lining.  

Well, I froze on final during my checkout and dumped the Eaglet
in from 10 or so feet.  (Actually, if the truth were known, I was
drawing a bead on another pilot when I froze, but that's another
story).  Sucker sure makes nice cartwheels.  The radio was
totally unresponsive, so I bagged it for the day and went home to
fix the damage.  The radio took about an hour to find a cold
solder joint in the IF amplifier; for this I'm very grateful,
that plane was flying with a time-bomb all this time. After I
fixed the cold joint I slammed the radio on the bench a few times
while monitoring the channel outputs on the scope; nary a glitch,
so that's OK. 

Anyway, on to the subject of this note.  I checked the plane over
for damage and found that the stabilizer had some cracked sticks,
also the monokote was on its last legs. I've tried to put it down
with CYA, but it keeps pulling free.  So I decided to recover the
whole surface.

I fixed the sticks, and found a broken hinge too; it pays to look
closely at the plane once in a while.

Went over to Phlyin' Phil's and got some Balsarite.  I used this
stuff to put down my dress lining material.  I gotta tell you,
that is some terrific stuff.  I gave the surface two coats.  Even
the slightly gas soaked leading edge of one side took the
Balsarite easily.  Then I put the material down using the heat
iron.  It stuck easily, and was easy to control.  The worst thing
I can say is that when I made a mistake and tried to pull it free
to reposition it, it took more force than I liked.  A couple of
quick passes with the iron tightened the cloth to perfection.  I
finished the job with two coats of butryate.

Now to spend the week screwing my head back around to fly like I
know I can.  Geez,  tests are no fun!