On Wednesday, March 10, 2021 at 3:08:24 PM UTC-5, Roy B. wrote:
Bob:
Thanks!

2 Questions/Clarifications:

1) Are you saying you actually sand the Mylar taped surface itself to improve adhesion?

2) I have something called a "wallpaper seam roller" ( a 1" wide hard roller on a handle) that seems it will do the job of you 2 ball bearings. Does that make sense?

ROY
Good description from Bob. I have had better results when I scuff the mylar with 220 as Bob describes. I'm not sure whether the roughness or the cleaning is the thing that gives the benefit. I NEVER use paper towels when doing the final wipe due to solvent possibly leeching contaminants from the paper. Just use a clean cloth shop rag. In use a wood block with a 1/8 radius sanded in the end to rub down. Use what works for your hands to apply firm even pressure. Make sure controls stay neutral until the adhesive cures.
One other thing from experience. You may be tempted to buy seals with adhesive per applied. In every case I have encountered them they were curved and would not lay down straight.
Have fun
UH