Foam Honey-Coming Weight savings

[David Lockhart]

With regard to the weight savings of the glue that has been mentioned by several people..............you can save the glue weight whether you honeycomb or not.

I've done wings both ways - to me, it is clearly not worth the fuss on thin airfoils (or stabs, or rudders/fins).  I use the same amount of glue either way, so even on the fatter wings, the weight savings is at most 1 oz per panel - and without a doubt, the wing becomes more prone to damage from hanger rash.

Dave

----- Original Message ----- 
  From: AtwoodDon at aol.com 
  To: discussion at nsrca.org 
  Sent: Wednesday, July 27, 2005 10:30 PM
  Subject: Re: Foam Honey-Coming Weight savings


  The amount of weight saved by honeycombing a wing is more than the foam weight.  It is a combination of the foam weight and the epoxy or adhesive you don't use in those areas.  Once the foam is honeycombed, take the template and very lightly mark the outline of the honeycomb on the inside of each wing skin.  Then only apply adhesive to the areas of the balsa skin that will contact the foam.  The combination of the foam weight reduction as well as the reduced adhesive will give you the greatest reduction.  Admittedly, the reduction is not large but when you consider reducing an ounce in a 11 or 12 oz wing panel, the percentage is respectable.

  Don Atwood

  you have the wing honeycombed, In a message dated 7/27/2005 7:22:37 P.M. Pacific Daylight Time, kerlock at comcast.net writes:
    Yup a little.

    Whether it's worth it or not totally depends on the amount of weight you're looking for. Actually cutting the honeycomb isn't too difficult or time consuming, but making the templates can be a little painstaking. However once you have them, you have them for a few planes.

    I am currently running a fairly thick tip section, and performed honeycombing on the outer half of the wing panel past the spars. It saved about an ounce per panel compared to the first set I made. So, you save a couple of ounces, and remove some mass from your wingtips. Does it help? I'm sure it doesn't hurt, and theoretically (being the operative word) it can help in dampening snaps and spins...but not a lot, unless your tips are really heavy to begin with. 

    If you're building an electric or a plane that historically comes out close to the limit, it could be worth the effort. I'm not sure it's worth it on a 10 lb or less plane.

    Just my 2 cents.
    -Mike
      ----- Original Message ----- 
      From: Jim_Woodward at beaerospace.com 
      To: discussion at nsrca.org 
      Sent: Wednesday, July 27, 2005 4:46 PM
      Subject: Foam Honey-Coming Weight savings



      Hi Guys, 

      Does anyone happen to have some experience in weight reductions from foam honey-combing?  Wing cores, stab cores, vertical fin and rudder cores?  Maybe a 25% weight reduction? 

      Thanks, 
      Jim W. 

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