I did it for 1/4" magnetic tape in the times of reel-to-reel tape recorders (also called magnetophones)

Althoguh the 'official' technical term would indeed by 'splice', in that sort of inverted snobbery way that means professional musicians refer to a band and a fiddle instead of an orchestra and a violin, in the industry (in the UK, at least), we do often refer to them (in film, not audio tape!) as joins, and the machine we use to help us make them is a joiner, and uses joining tape.

Generally speaking, we used to reserve 'splice' for the kind of cement joins which would be used for neg. cutting, but would not be employed for a cutting copy (aka workprint) as in your context here.

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Note added at 1 hr (2010-11-07 15:44:15 GMT)
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I never said one didn't use a cement splicer with positive copies (in any gauge) — however, cutting copies (aka work(ing) prints) are traditionally tape joined, for the very simple reason that the editing process very often requires one to undo and redo joins several times, and the cement splicing process means you lose a frame each time.

Note also that cinema projectionists use tape joins when making up projection reels, putting titles, adverts, trailers, and of course the individual film reels all into one big roll for automated projection purposes; and even though this technology is gradually being supplanted, it is still very much current.