AdministratorSeptember 3, 2020 at 9:23 am
after cleaning the surface with Isopropynol or similar, did you cross-score the surface with the likes of a Stanley blade or similar?
around 18 years ago, We didn’t do this once and got the exact same result as you have!
it is definitely better to check if you have the correct compatible adhesive too. we tried arldite once and as much as it worked, we found the adhesive to brittle and rigid. so if your board is expanding and contracting in sun and cold days, it will move where your adhesive will be rigid and both will separate.
you also have to be careful about the quality of the ACM -Vs- adhesive.
some two-part adhesives mix and cure at a high temperature. this can cause dimpling on the face of cheap or thin aluminium skinned ACM. not noticeable in the workshop, but once on a building front and the sun shines on it, it looks like the surface of a golfball.