To verify that sealants will cure when closed cell foam is used as a backing material we’ve applied two types of sealant to the foam in the proper orientation.

We formed a sealant channel, lined either side with silicon release liner, to which the sides of the sealant joint would contact.

After curing for seven days we opened the joint and pulled of the liner.

We cut through the joint and observed that the sealant was fully cured.

We also noted that the sealant did not adhear to the Polyethylene foam.  When we compressed the sealant, the foam released from the sealant.

This illustrates that BackrTape will provide a fully functional sealant bead with proper 2 sided adhesion.