All,
     I'm wondering how the use of Microballons and glue would strengthen a repair? I've glued the main cpieces together of a crash and have some gaps that I would like to fill to smooth out the repair. Would microballons and expoxy add some strength to the join of the pieces?

My feeling is yes - But I don't really know.

       

Microballons are a fairing material. They are not structural. They do not provide a structural glue joint, they in fact weaken it considerably. Cabosil, microfibers, wood powder (yup, like balsa dust or any other wood), and West Sytem Structural fillet material are all structural addatives that will add strength to a joint. They will have different sanding and handling properties. One of the best things out on epoxy modifyers is prublished by System Three Epoxy in Washington. Its called "The Epoxy Book". Its really more of a small shop manual on epoxies and fillers. Not just an advertising piece for their products but a how to on epoxy materials and handling. Its in most boat builders shops regardless of what system they use. Your can find it on their online catalog. Also They still I think put together an inexpensive kit of small amounts of different modifiers, I think with sample of one of their glues for a nominal price. Probably 4 to 6 oz of 4 or 5 kinds of fillers in it. Will give you good experience and is enough to use for many models for fillets and stuff. Very well worth the nominal costs, both of these.

bob branch

All,
     Thanks for the responses. 

Now knowing your opinions and past experiences with Microballoons. I will use it as a simple fill (possibly) and then I will epoxy a "patch" of fiberglas and carbon fiber over the repairs. 

I'm lucky (in a way) that this was not a pretty plane to begin with and the reason for the repair is that the plane was an overall good flier and still could be.

I just didn't want the outboard wing sheering off in the first manouver