F61 Heavy Duty Contact Adhesive. STYCCOBOND F61 is a solution of synthetic rubber and resin in flammable solvents. The adhesive should be applied by fibre spreader or brush and combines quick drying with a long open time. It is suitable for use over normal underfloor heating installations and will withstand normal wet cleaning techniques. The formation of an ‘instant’ bond makes it particularly suitable for use on stairs and steps. STYCCOBOND F61 can be used for securing PVC and rubber edgings, covings and nosings, floor and wall coverings with backings of PVC, rubber cork and most textiles.