Because sometimes you need to seal up a joint, and the materials that can do the job don’t play well with adhesives. When working with Delrin, you’re thankful for the excellent machinability, less so for how much of a struggle it is to get anything to stick to it. Could be worse, right? Could be PTFE (Teflon).
Even this silicone sealant is a “sort-of” solution, and it sticks to everything. Always threatens to make a real mess of things. But it’s reliable for waterproofing and can take a variety of abuses from heat to chemicals. And it comes on a “job-size package.”
Having just gone through about a dozen of these things on a single job, we may take some issue with that descriptor. And the rather optimistic 10-20 minutes to being tack-free. But it’s still impressive and effective stuff.
And compared to some other goop around here, doesn’t stink to high heaven.