I am building a fiberglass (Rocketry Warehouse 38 special) for my son. He hates to build them but loves to fly them. He has his L1. I have ran out of colloidal silica. I bought some micro balloons a long time ago and have never used them. Could I use that in my West Systems 105 for the internal and external fillets? Or should I use some Aeropoxy ES6209. I have never used it. I have some I won in a volunteer raffle at AirFest a couple years ago.