I have experimented in my shop to find out how
well various caulks and tapes stick to different
types of paper. Some of the 12-inch-square paper
samples I used were fresh out of the box, others
approximated the damp or dusty condition of a job
site. I applied three beads of sealant: a 3/8-inch
bead right out of the tube; a 3/8-inch bead which I
tooled to flatten it; and another flattened bead
used to adhere a second piece of paper. I allowed
the samples to dry for about 48 hours, then
submerged them in water for 72 hours. This level of
exposure to water is severe, but I felt that it was
justified because I have worked on jobs where caulk
was exposed to heavy rain and runoff for 24 hours
or more.
After taking the samples out of the water, I
pulled and tugged the beads to see how well they
had adhered. The results, which are shown in the
chart below, aren't scientific, but are based on
careful observations from which I was able to form
an opinion about which caulks worked best relative
to the others.
|
In general, the tooled caulk adhered better than
the straight 3/8-inch bead, probably because of the
increased surface area. Most of the caulks didn't
stick well to Tyvek Stuccowrap, possibly because of
its ridged surface. Two of the caulks -- VIP's
Elastomeric Ter-Polymer and Polyseamseal --
softened significantly and all but lost their
adhesion.
Clearly, the Quad caulk performed best with all
membranes. Three other caulks -- Rainbuster No.
900, Pro Choice Neoprene, and Dynatrol I-XL -- were
close seconds. I also experimented with EZ Seal, a
tape manufactured by Fortifiber consisting of
hot-melt glue on paper, and with Tyvek Tape. While
most contractors will not be applying saturated
tape, both of these products performed well,
although it was difficult to peel away the EZ
Seal's backing paper to expose the adhesive, even
after the tape had dried in the sun. -- R.W.
|