model 4 aileron foam ribs

[foxkit3]

Hello, I was wondering what type of foam is used to for the ailerons foam ribs ?

Thanks

[mr bill]

I have a set of symetrical airfoil flaperons with balance weights that are surplus to my needs. They still have the plastic liner on them. Let me know if interested.

[HighWing]

I think the foam is urethane foam. One consideration on chosing the foam, it needs to be fuel proof as a spill at the filler neck most likely will find it's way into the slot on top of the flaperon. Another issue that resulted in the recommended lubricant, is that the wrong lubricant can affect the foam as well. My guess is that Home Depot foam is either Polystyrene or Styrofoam. In home construction, chemical resistance to their foams is not an essential requirement. another thought is the Depot foam starts at one inch thickness. ACS foam is available in fractional inch thicknesses.
I would suggest checking out Aircraft Spruce and see what they have. On each foam listing, they will have some physical characteristics that will help you choose what you want. I used it extensively on my current Model IV. All empennage ribs were foam core glass laminates.

http://www.aircraftspruce.com/categories/building_materials/bm/menus/cm/foam.html

Lowell

[Geowitz]

I was going to suggest the same... rigid urethane. I recall peaking into my flaperons and seeing a yellow rigid foam epoxied to the aluminum skin. I have aslo heard the same about the fuel and lubricant breakdown issues with using the incorrect foam.

[foxkit3]

Thanks guys for the info