1960s RAF used waxed string although I have seen the tryton(? Plessey strapping?)type was in use but all done by hand not with a "gun"!Beeswax was used and one electrical section actually left it on simmer while away at lunch and it caught fire!!Yes it was me a "liney"who was called to the thick smoke coming from the workshop!!No damage apart from the string and beeswax!!!