Closed Cell Backer is a low density polyethylene foam backing rod. It is closed cell and is CFC free. It is available in a range of diameters up to 50mm. Excellent rebound recovery. Excellent chemical resistance to most commercial chemicals, solvents and acids as well as oil and compatible with all sealants.
Orange Backer Open Cell is a medium density, firm, open-celled foam for supporting sealants in movement joints. It can be stretched, squeezed or bent to conform with irregular surfaces. Because of its resilience and co-efficient of friction it will remain as placed.
Open cell polyurethane foam is to be compressed at a minimum of 25% and a maximum of 75% when placed in joints to be sealed. This one size of foam can be used in a much wider range of joint sizes than one size of closed cell polyethylene foam backer rod.