Plank Bender, I'm a LAME, and I would be using PR1428 if you can get your hands on it? Tho it dries a deep purple colour, it is highly flexible and UV resistant, specifically made for windshields, especially floating ones like Cessna's, or Piper windows attached by screwed on tabs.
The PR1422 is brown in colour when dried, but was made for fuel tanks and degreasing resistant, tho not very UV or flexible when aged cured. It would do for several years, but PR1428 would be better. Then you could also apply 2-pack touch-up paint via a touch-up brush over sealant. Job would be very presentable & professional
The Bostik stuff that others are talking about, should be of Neutral Cure only, and would be found in a Paint Trade Centre outlet of some sort. Neutral Cure marine sikaflex would also be allowed, and it maybe a pre-mixed colour the same as your pre-coloured to your aircraft paint work.
Personally I'm fussy in those situations of windows, and would only use a plastic or phenolic or nylon scraper to remove old sealant. Just remove the remaining sealant with Isopropanyl, Toulene, or a goo remover. Don't be scratching it like others recommend!!!! Why scratch a good fine surface unless there is corrosion there??!! Scratching an alodined coating off alloy would be like scratching your skin with a knife blade to make sure old skin cells were removed, tho no cancer there
... Unless corrosion, just clean surface, and re-apply. Perfection is for visible areas, and without a trained person or eye on job, all your doing is prompting future problems.
NEVER USE A WIRE BRUSH!!!!
... maybe if you PM me, we can talk on phone, but you should be alright with the above directions.
PS - use a good quality masking tape, and not too large a filler bead of sealant, just enough to do the job of keeping the water out, and not enough for the sun to harden, and your washing methods to risk catching the bead of sealant off.
