A wooden raft has a mass of 83 kg. When empty it floats in water (density 1000 kg/m3) with 65% of its volume submerged

A wooden raft has a mass of 83 kg. When empty it floats in water (density 1000 kg/m3) with 65% of its volume submerged. What mass of sand can be put on the raft without it sinking?