Stelmax 1961 Gap Filler & Sealant is an easily applied RAL 7016 PVC resin, pigment, plasticiser and solvent mix, that will gap fill and bond readily to form maintenance free joints of exceptional strength when used to bond and fill rigid and plasticised PVC. Good adhesion can also be achieved when used with many porous substrates. 1961 is extensively used within the window industry for the installation of frames and attachments. It has a higher solid content than 1965 and can therefore be used for larger gaps than 1965. 300g cartridge.