The adhesive is produced for gypsum plaster which is the same material as the plaster mouldings to ensure the best possible fixing and colour match. Just mix with water to the required consistency. This should be the thinnest consistency necessary to work with. This adhesive sets very quickly. We advise you only mix the quantity required to fix one piece of plaster at a time. Damp the surface of the plaster with water before applying the adhesive to it. Please note you will need 5kg of adhesive for approx 7 lengths of average size coving (circa 90x90), on straight walls. If your walls are not straight or have many imperfections this will require more adhesive to get a perfect finish.