[56窗户] 维护提示 | 密封胶未完全固化在其上粘贴金属胶带

While this practice has been commonly used by operators, we have the following comments and recommendations:

a.  Generally it is preferred not to use this practice because when the tape is peeled off, sometimes the integrity of the sealant gets compromised, thus causing the need to rework the sealant.  The tape can also inhibits the outgassing of the cure, resulting in an inconsistent cure.

b.  We recommend the sealant be allowed to cure as long as possible before applying tape.  Note that cure times for polysufide sealants are given at standard temperature (i.e. 77F).  The cure time doubles at 57F, and below 50F, the cure chemical reaction practically stops.

Also, applying heat to the sealed area can reduce the cure time, but maximum elevated temperatures should not exceed 140F.hrs.

Periodically (after each flight) inspect the tape to check if not pilled off, and recover it if required.

The tape can be removed at earliest convenience once sealant is fully cured.  When speed tape is removed, carefully inspect the sealant to ensure that the sealant is adhered to the edges and that it is has cured properly (e.g. not tacky).

Additionally, if the aircraft must dispatch before the sealant cures, can apply speed tape over the sealantafter it has cured to a tack-free state.The tape can be removed once the sealant has fully cured.