On Sunday, 9 August 2020 at 17:10:32 UTC-6, wrote:
Gaffers tape is a polyurethane over a cloth laminate and may not stretch the way you require.
Also much thicker.
Gaffer tape is designed specifically not to leave glue residue behind when removed (specifically useful eg. in the film industry, where tape has to be applied to carpets, clothing, sets etc.). It's basically less-sticky duct tape. I wouldn't use it on a glider, unless you have a phobia about glue residue.