Dipterocarpus grandiflorus oleoresin potency as coating on wood and zinc in Borneo coastal building

In East Borneo, villager who live on the coast, build houses on the sea. Houses on the sea or coast made of wood and zinc / aluminum roof. The wood of coastal housing is very easy to change its dimensions due to high coastal air humidity, while the zinc of the roof of the house is easily corroded due to corrosion of sea water containing salt. Therefore wood and zinc must be coated so that it is resistant to moisture in the air and sea water vapor. One of the coatings used traditionally is oleoresin from keruing (Dipterocarpus), but it has never been scientifically proven. The study aims to determine the stability of the dimensions of oleoresin keruing resistance as a wood coating and determine the corrosion resistance of zinc that has been coated with oleoresin. Dimensional stabilization measurements using meranti wood in longitudinal, radial and tangential directions. Measurement of zinc corrosion by means of galvanostatic polarization technique. Test results show that meranti wood coated with oleoresin keruing has more stable dimensions compared to uncoated. Whereas zinc coated with oleoresin keruing is more resistant to corrosion than zinc which is not coated.