Why would you use silicone? I don't. Butyl has been in use for nearly 90 years. Duct seal (at least Gardner benders version) was designed to be a less sticky alternative to butyl. Electricians want to keep drafts and bugs out of their conduit, but would whine like little girls about the butyl residue that was left behind when doing rework. I suspect that duct seal is a butyl composite, but I can't find specs as to what it really contains.
In my (worthless) opinion it is a disservice to the members to encourage them to spend extra money on a less effective and less proven butyl substitute when butyl tape is cheap, easy to find, and proven. That is all.
In my (worthless) opinion it is a disservice to the members to encourage them to spend extra money on a less effective and less proven butyl substitute when butyl tape is cheap, easy to find, and proven. That is all.
