A few tips for adhesive prep on these is to clean with isopropyl alcohol or acetone. Wipe it wet and immediately again with a clean cloth to catch any residue that is floating while it is wet, do this both to the surface and the sight. I do it at least twice.
Also it wouldn't hurt to rough the bead lightly with some course sandpaper just to give it a bit of "bite" for mechanical adhesion.
When using JB weld or other two part adhesive it's always advisable to make a test batch and make sure it cures before you use it.
Also when mixing put equal amounts onto your mixing surface (I use paper plates) and mix with the end of plastic fork or knife. Mix very very thoroughly and apply with a toothpick, never apply with the mixing item as you risk getting uncured adhesive on your part.
Lastly always coat both surfaces lightly, it's easier to get 100% coverage when both parts are coated lightly than one heavily dripping all over. Then scrape whatever minimal squeeze out you have with subsequent toothpicks or other square or round edged item of your choice. If you choose to clean with a solvent saturated q-tip or other be very brief as you don't want to compromise your bond with the solvent. I rarely clean around anything bonded with solvent, either tape it off or be more careful.
This is based on many years working in composite tooling, composite repair and per aircraft spec, or at least it was at the time... been awhile.
