Re: Hollow body swirl
I was wondering....... why not fill the body with sanding sealer, let it soak for a bit, then drain and let dry. You'd probably need some type of rotisserie for drying to keep the wet sealer from pooling.
also, instead of putting sand in the balloons, why not just use water?? It's obviously has the same density as the water your dipping in. If you have large enough balloons, they may seal the f-holes when full.