In not sure of the brand, think it's Thomas and Betts, but I use an uninsulated crimp sleeve, a ratcheting crimper, and marine grade shrink tubing with the glue in it. Got at the local big box store. Parts are designed for splicing UF (underground feeder) cable for direct burial.
I do everything I can to avoid 115 volt inline splices. They are prone to failure. Better to splice inside a junction box if possible.
Rich, KE4GNK/AE, Overkill Engineering Dept.
'The Silver HamShack' ('07 International 22FB CCD 75th Anniversary)
Multiple Yaesu Ham Radios inside and many antennae sprouting from roof, ProPride hitch, Prodigy P2 controller.
2012 shortbed CrewMax 4x4 Toyota Tacoma TV with more antennae on it.