wing core foam source?

[bob branch]

Could someone tell me where I can order the 1 pound foam folks are using for wing cores?

Thanks,
bob

[Leester]

Go to the vendors corner The Control Line Guy  Crist Rigotti makes foam wings.

[Bill Little]

Could someone tell me where I can order the 1 pound foam folks are using for wing cores?

Thanks,
bob

Hi Bob,

I don't know a source for the foam, but I believe Crist can tell you where he gets his. (I think the others guys must have thought you wanted wings!  )

[L0U CRANE]

Bob,

If I'm not mistaken, most (much?) of the common, insulation type white styrofoam available from serious lumber yard type sources is 1 lb/cu ft. You can recognize it easily, as it tears out popcorn-like chunks when you try to sand it two ways... From what I've seen, this stuff is available from 3/4" to over 2" thick. ...should serve most purposes...

This stuff has NO inherent strength of itself, but makes a good 'form' for holding surface sheeting to shape and for occasional surface spars and reinforced 'clips' (Bob Hunt's term for "ribs" for such things as wing-mounted landing gear hardwood carriers), center sections and tip attachments.

Cuts nicely with a hot wire, and sands well  with fairly coarse paper - in one direction! - to get the shape. Finer grade paper, down to say 150 grit - in one direction - refines it to be ready for surface sheeting. Vacuum the crumbs out before attaching sheeting, whether with a THIN wipe of slow epoxy, or contact cement, or 2-sided tape, Gorilla, or whatever.

[Dwayne]

This is why I love this forum 
Thanks Bob
Dwayne
 
    

[Keith Spriggs]

Hi guys:

 If you do the math (and I'm not inclined to...) that adds up to quite a few holes drilled into the mold at 1 inch squares. Later - Bob Hunt

If they are 1/2 inch from the ends I get 35,232 holes.  Very interesting information. Thanks for passing it on.

[phil c]

Just an addendum to Bob's thorough disscussion of foam.
Almost all of the foam we use(1 lb. bead board) is produced for building EIFS(External Insulation Foam System) siding on high end houses.  All the fancy stucco effects you see are done this way.  The official spec is very stringent as to solid bonding of the beads to each other , the density, the aging, and the cutting of sheets.  It also allows a range of .9-1.0 on the density, so naturally almost all the foam comes at .9-.91 to save the foam producer 10% on materials costs.  The age of the foam is very important.  It takes 6-8 weeks to stabilize after molding.  If you try and cut a wing from really fresh material, which they aren't supposed to sell as EIFS, it will bend, warp, melt funny, and cause all sorts of problems.

[Ron Merrill]

WOW, would you look at Bob's shop, you can eat off the building surfaces. I have to wear a dust mask to go into mine. Thanks for the info. Ron 

[Paul Smith]

Back when I was in Wichita, there was a local "foam farm" where they grew 8-foot cubes of generic white foam.   They have a 10-foot square cast iron cutter frame with holes on 1" increments.

For a modest fee, they would slice & dice a cube any way you want it.

I expect you should be able to find similar ops in most major cities.

[L0U CRANE]

Thanks, Bob!

Almost more than we really wanted to know, but it turns out we want and need it...

Merry Christmas and Happy New Year!