Yes there is. I have used it in conjunction with an epoxy similar to West
to finish the wings and it works great. The Ultra-300 cost about 1/2 of
the West System and chemically is the same. Easy to sand and all that
stuff. The pin holes are covered with the same epoxy and some cabosil
added.

Below is the label (copy) of the product.
- - - - - - - - - - - - - - - - - - - - - - - -
-- Aircraft Lightweight Fairing Blend #5. --
DESCRIPTION:
Fairing Blend is a mixture of Microballoons, a reddish
brown hollow sphere of phenolic resin, and Microspheres
HGS - 14, a lightweight hollow glass aluminosilicates.

This tested Blend is used in Ultra - 300 LV resins to
make superior light weight fairing compounds and fiber
glass surface filling and finishing. Easily sanded with
outstanding feather edge qualities not found in other
products.

ALUMINOSILICATES
CAS # 1327-36-2

CAUTIONS:
The Microballoons portion could ignite spontaneously
if stored in warm areas without adequate ventilation.
A respirator or proper dust mask should be used when
working with microballoons mixtures such as this "Blend".
Dust can cause irritation of the respiratory system.
Contains trace amounts of free formaldehyde (less than.
1%), which has been identified as a potential carcinogen.
This is a nonstructural product. Dry powders can build
static electrical charges when subjected to friction by
pouring, conveying or mixing. Proper safety precautions
including electrical grounding, inert atmosphere, etc.
should be taken when handling near flammable liquids.
- - - - - - - - - - - - - - - - - - - - - - - -

Gary Hall, FXE
http://www.uslan.com/hinge-kit.html

Subject: [LML] cabosil/micro balloons

From: "Dan Schaefer" <dfs155@earthlink.net>

Date: Tue, 02 Sep 2003 09:23:27 -0400