Thin, Medium, Thick, Gel, Flexible --- What should I use??

For sealing and finishing applications see our Customer Idea: CA Finishing for a great detailed explanation.  

Bonding:  The thickness to use depends on the surface to be bonded together.  To determine this, put a small amount of Cyanoacrylate on the surface.  Ideally it should slightly absorb into the material, but a bead should still remain on the surface.

Bonding dissimilar materials:  To bond wood to metal or metal to glass, Flexible is the answer.  The rubberized cyanoacrylate bonds, allowing for different expansion rates during temperature changes.  This material also excels where shock and vibration may be present.