Conference vmszoo::rc

< 1. Will my plane end up much heavier this way compared to using painted super
     coverite? 

No provided the Balsa used is not the bleached white (very soft balsa). This 
type of Balsa soaks up too much resin and adds weight.

< 2. Is Epoxy paint the way to go?  Does it spray as easily as the dope?  I
     normally thin the dope almost 50-50, does the Epoxy paint need to be 
     thinned similarly? 

Hard to beat the finish of epoxy paint: however it is expensive and I am 
suspect of its toxic effect during spraying. I cannot prove this but would be 
interested in any comments. We have a two pot mix automotive paint (Acran)that 
is a great finish but requires a re-breather when used.

< 3. What should I use for sanding sealer and primer?  I want something that
     will stick to the fiberglass WELL. 

Normal Acrylic Automotive paint sticks like Sti!!! to a blanket. No worries.

< 4. What can be used for filler UNDER the polyester resin? From what I read you
     can't put spackle under it. 

Resin and micro balloon mixed to a paste for large holes. For small holes grain
etc a very heavy coat of primer sanded off completely leaving primer only in the
holes before giving a light coat of primer keeps the weight down and fills all
holes. 

< 5. I've heard of using a toilet paper tube on a shaft and "rolling" off the
     excess instead of squeegeeing, anyone got experience either way? 

No the technique is to use a full roll of toilet paper and roll it over the 
wetted area, any excess resin is absorbed into the paper and the wetted  paper 
is discarded. (its too hard to use for the intended purpose soaked in resin.)

John.

    There are easier methods. 
    
    							Tom

    Re .1 - thanks for the suggestions AND humor, I got a good laugh
    from the toilet paper comment.  I have done some more experiments
    with filler (DAP & Microfill) and to my surprise found that the
    resin hardened fine over both.  I really recommend the Microfill,
    it sands at the same rate as balsa and is EXTREMELY lightweight.
    I usually end up with several large dings to repair before I'm done
    sanding, so a good filler is essential.  The heavy primer coat almost
    completely sanded off sounds like the way to go to get rid of grain,
    although it seems that the glass cloth would do that anyhow.
    One thing I noticed with my little experiment is that the resin
    does NOT harden very well over CA.                    
    
    Re .2 - Glad to hear it, wish I knew what they were!!
    
    				Thanks, keep the comments coming!
    							Bill
    

    
    Got some of that .6 oz cloth from Dan Parsons Products.  Dan swears
    by thinned epoxy, not polyester resin, for the binder on the glass
    cloth.  He recommends Enviro-Tex epoxy, available in many hardware
    stores and such.  It's normally used to put those thick "plastic"
    coatings on tables, bars, etc.  He thins with an equal amount of
    isopropyl alcohol.  I'm thinking about giving it a shot, any
    comments, experiences, or recommendations out there???

    							Bill

    The subject...  Overlaps...  again...
    
    (For related notes, see "Let Us Spray" around 288.281...)
    
    In Let Us Spray, we talked about getting glass to wrap around the edges
    and short radius curves...  
    
    This weekend, I covered by Goldberg floats with Dan Parson's glass and
    K&B resin.  It went very well, except for the overlaps...
    
    What I did was I used 1 piece of glass for the entire bottom, and
    wrapped the edges up around the sides...  I was able to get good
    corners.  However, I used resin all the way to the edge of the glass,
    which caused the edges to fray and the brush to load up with glass
    fibers...  OK, a little sanding and it is smooth again, but a bit
    of a hassle.
    
    Then I covered the rest of the floats with another piece of glass. 
    Again, it went on really well.  This time though, I used masking tape 
    on the edges of the glass.  Then, I wrapped the glass around the bottom
    edges and onto the bottom, but not all the way to the tape.  Again, the
    edges came out well.  
    
    After curing, I trimmed off the excess.  However, I am now left with
    a fiarly sizable edge.  Now, my questions...
    
    - If I sand down the edge now, I risk cutting into the edge and/or the
    bottom glass.  So, do I go ahead and sand as best I can, or do I do
    my second coat of resin (to seal the glass) and sand it after that??
    
    - Does anyone have any suggestions on how to better handle the
    overlap??  I have read (and re-read) the notes, the flyer that came
    with Dan's glass, and Jeff Troy's book on finishing.  I get the feeling
    that I almost have this down, but not quite!
    
    Thanks!
    jeff
    
    

    Jeff,
    
    Sand the overlap only lightly at this point.  Apply the second coat of
    resin and sand some more but take care not to cut into the bottom layer
    of cloth.  The overlap may still exist to some extent at this stage but
    not to worry.  Apply K&B primer with a brush, doubling up in the
    overlap area if necessary, then sand it almost all off.  Repeat as
    required (1-or-2 more coats should suffice), spraying if you can as
    this makes sanding easier.  By the end of this process, the overlap(s)
    should be completely invisible.
    
    I've never paid an excess of attention to the overlaps as they just
    seem to take care of themselves in the process of priming/sanding.  Let
    us know how you fare.  (And, ain't that Parsons cloth some sweet
    stuff?!)
						 __
				|      |        / |\	   	       
      	         \|/		|______|__(o/--/  | \	   	       
      | |        00	       <|  ~~~  ____ 04 ---- | --------------------
    |_|_|        (O>o		|\)____/___|\_____|_/	   Adios amigos, Al
      |     \__(O_\_	        |	  |___/	 o	   (The Desert Rat)

    Al sure was right!  The overlaps just disappeared while sanding off the
    second coat of resin.  The overlap is now slightly visible and barely
    noticable to the touch..  Should be perfect after the primer!
    
    Thanks!
    jeff
    

Speaking of fiberglassing the leading edges of wings.
Well actually Bob Collins and I were just saying that in mail...

I would like to apply some (not much - keep it light) fiberglass
to the leading edge of my Chup - but I don't dare use Dan Parsons
cloth as I would like to put down one piece that would be about 1/2" 
wide by 60" long - try that and not unravel it!

So does anybody know where I could get some nice narrow fiberglass tape
so that I would not have an issue with edges?

Maybe I'm just not doing things right and I could somehow cut and maintain
a thin strip of Parson's cloth.

I just need to strengthen up the leading edge.  Seems like I must have patched
up and painted it a half dozen times now.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Small strips of fiberglass used to be sold as control line hinge
    material. Sterling used to provide a strip just like what you're
    looking for with their models. This is old (12 years or more ago) info
    but you might be able to find some if you look in the hinge areas of 
    the catalogues and hobby stores.

    (Kay, Jim, I moved your notes here with the other fiberglass notes..)
    
    Kay, I believe you have 2 alternatives...  
    
    1 - Goldberg and Dubro sell nylon or fiberglass "tape".  Goldberg
    list's their tape on page 246 of the Towers catalog.  Widths are
    3/4", 2�", 4" and 6".  Tape is applied with glue or epoxy...  Obvious
    problem here is thickness and resulting weight...  But at least the 
    edges are "finished".
    
    2 - Use the parsons cloth...  Lay out the cloth on a table.  Run 2
    parallel pieces of masking tape, with enough space in between for the
    desired width of the cloth.  Cut the cloth down the *middle* of the
    tape.  The tape will keep the edges from fraying...  A straight at this
    point is not important, just stay on the tape..
    
    Leave the tape on as you apply the glass, using resin right up to the
    tape.  (After you get it layed up, use additional tape and tape the
    tape/glass down to the wing.  This will prevent it from lifting..)
    
    Once cured, cut off the tape/glass with a sharp knife..  Knock off
    the frayed edges (sound familiar Al?).  Apply a second coat as needed, 
    or simply cover with film...
    
    I basically used this method on my floats and they really came out
    pretty well...
    
    cheers,
    jeff
    

    Kay,
    You might try that tape that comes in 1", 1 1/2, & 2" widths, all
    60" long. Naturally I can't think of the mfg. even though I use
    it on almost every plane for trailing edge stiffner. It has red
    and black lettering on the package and is about $2.50. It's about
    a medium weight and cuts without fraying a little better than the
    big sheets of glass cloth. You might be able to epoxy on a 1" strip
    with all the excess hanging off the bottom, then razor blade off
    the excess when the 'poxy is not quite set up hard. Then a light
    final sanding to fair in the lower edge.
    On my latest foam stabs, I tried the pine dowel for the leading
    edge trick. This works so slick that I'll never go back to the old
    sand & shape l.e. It cuts 50% off the build time and gives you a
    dent proof l.e. Now getting ready to use it on a new blue foam and
    birch, 120" wing.
    
    Terry
    

    Re: .8, Kay, 
    
    Jim, Jeff and Terry have pretty much said it all except for the fact
    that, after going to all the trouble of applying lightweight glass
    cloth (like Parsons' .6-oz stuff), I'm afraid you'll be disappointed in
    that the amount of strength/dent resistance gained will be so slight as
    to be virtually negligible.
    
    Conversely, if you go to a cloth-weight substantial enough to achieve
    yer' objective, yer' gonna' add considerable weight to the model.  My
    advice is to quit running into things ;b^) and use Terry's dowel
    leading edge idea on subsequent models.
    
    BTW, Jim..., I don't think the material provided for hinges by Sterling
    and myriad other kit manufacturers was fiberglass.  Rather, I'm certain
    it was some sort of nylon or other wonder fabric.  Glass would make an
    especially poor hinge as it becomes extremely brittle when glue, resin,
    etc. hardens on it...a few flexes of the control surface and the hinge
    would break.
						 __
				|      |        / |\	   	       
      	         \|/		|______|__(o/--/  | \	   	       
      | |        00	       <|  ~~~  ____ 04 ---- | --------------------
    |_|_|        (O>o		|\)____/___|\_____|_/	   Adios amigos, Al
      |     \__(O_\_	        |	  |___/	 o	   (The Desert Rat)

>    2 - Use the parsons cloth...  Lay out the cloth on a table.  Run 2
>    parallel pieces of masking tape, with enough space in between for the
>    desired width of the cloth.  Cut the cloth down the *middle* of the
>    tape.  The tape will keep the edges from fraying...  A straight at this
>    point is not important, just stay on the tape..
>    
>    Leave the tape on as you apply the glass, using resin right up to the
>    tape.  (After you get it layed up, use additional tape and tape the
>    tape/glass down to the wing.  This will prevent it from lifting..)
>    
>    Once cured, cut off the tape/glass with a sharp knife..  Knock off
>    the frayed edges (sound familiar Al?).  Apply a second coat as needed, 
>    or simply cover with film...
    
I choose option 2 - thanks Jeff.

I had heard of this before but having never done it I was in my workshop
puzzling over how to...

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
    

    Actually, there is a number 3...
    
    3 - spread thin CA glue on the surface and let it soak in...  I have
    found that CA really toughens up light balsa...  I also use CA on any
    threads that I make in any wood (servo rails, wing hold downs).
    
    cheers,
    jeff
    

    At our clubs "Show and Tell" last night, I saw a very interesting
    method of fiberglassing...  This guy used white glue thinned 50/50 with
    water.  He fiberglassed over a shaped piece of foam with 1 layer of
    thin cloth then sanded it..  It came out glass smooth (ALMOST as nice
    as my polyester resined floats :-)  Very light weight and he said it
    was easy to do...
    
    This was on a non-load bearing surface so that strength ws not a
    consideration...  It did seem to be a very hard surface though...
    
    He also built a very nice, one piece engine nacelle..  He formed the
    glass over a foam former then melted out the foam with acetone...
    
    I think I will try the white glue/glass on the nose of my C-45...
    
    Cheers,
    jeff
    

    Although this note is on fiberglass hints, I need your advise on the
    solution.
    
    I am still building on the Ford Trimotor and need a solution on "to
    fiberglass or not on the cowling.  I have completed the carving of the
    cowl out of solid balsa and covered the outside with 3 layers of
    fiberglass.  The inside of the cowl has not been carved out leaving
    about a 1/8th inch balsa inside.
    
    In fitting the cowl over the engine and to the firewall, the drive
    shaft of the engine was off center.  Since I can't move the engine off
    the center line, I cut off the round radial cowl and reglued it with CA
    thick to get it centered.
    
    Question:  Should I now add glass cloth to the outside or glass the
    inside of the cowling?
    
    Ollie
                                                    

    That's a tough question without being able to see/feel it....
    
    The cowling is non-structural.  Therefore, you only want to make it as
    strong as it has to be to stay put.   Anything more will just add
    weight.  Another consideration is to make it fuel proof.  Fiberglassing
    the inside would accomplish that, but so would painting it..
    
    Can you explain a bit more why the repositioning of the cowling is
    relevant to the decision of more fiberglass??  Is there now a contour
    that doesn't match?
    
    cheers,
    jeff
    

    Jeff, thanks for the reply.  
    
    The reason for the question is that the cowling is just thick CA glued
    to the cowl extension.  I'm don't know if this will hold the cowl on
    through continuous flights.
    
    It has taken me about a month to carve the cowl and extension out of
    solid balsa (about 4" x 4") and I don't want to have to repeat this
    part of the building again.
    
    Hopes this helps.
    
    Ollie
         

    If you think you need more strength in the attachment of the cowl,
    fiberglassing the seam from the inside would certainly fix that. 
    I would only fiberglass the outside seam if it makes sense in
    terms of how it looks.
    
    cheers,
    jeff
    

    in building my Long-ez I have to flass everything, this is mostly for
    structural strenght. The plans tell me to glass the wing "then" attach
    the winglets (rudders). As I fit the winglets to the wing there are
    gaps here and there. I would think that if I glassed the inside of the 
    winglet then epoxy the winglet to the wing it would be easier to fill
    in the gaps before covering with glass.
    Does anyone have any light on this or an easier way??
    
    Thanks
    Bruce  

    Bruce, in the building of the full Long EZ, the winglets are attached
    in the same manner in that the wing is glassed, then the winglets are
    attached.
    
    The winglets are attached by using "flox" (a mixture of epoxy ang
    ground cotten.  This mixture fills all the gaps between the end of the
    wing and the base of the winglet.  After attaching, glass cloth
    (several layers are used to provide strength in this area.  Note, both
    the inside and OUTSIDE of the winglet are glassed.  There was one
    builder who glassed only the inside of the winglets only to see both
    depart the wings on the first test flight and found it rather hard to
    land without rudder control.
    
    Hope this helps.
    
    Ollie

    
    So Ollie,
    Are you saying to glass the wing after the winglet is attached??
    I will flass the out side of the winglet it would just be easier to
    glass the inside before it gets attached.8^)
    
    Thanks
    again
    Bruce

    Bruce, the top and bottom of the wing is glassed leaving the end or tip
    of the wing with the foam showing.  To the tip, use "flox" to attached
    the bottom of the foam winglet to the tip of the foam wing.
    
    Once attached, glass the winglet by starting 2"or 3" on the top and
    bottom of the wing and running the glass cloth up the inside and
    outside of the winglet.  The number of layers f glass cloth you use
    determines the strength you feel you need to hold the winglet to the
    wing.
    
    Ollie