Glass micro balloons         Hollow glass bubbles of an irregular interlocking shape and when mixed with resin/hardener the irregular shapes provide advantages both as a lightweight filler and reinforcement. The finished resin is non water permeable, the balloons can be added to resin up to 30% by weight. The composite density at this ratio is approximately 0.52 g/cc     UKR19: 0.1 kg Glass micro balloons £6.20 Qty UKR20: 0.25 kg Glass micro balloons £10.70 Qty UKR21: 0.5 kg Glass micro balloons £18.30 Qty UKR22: 1.0 kg Glass micro balloons £30.35 Qty