After potting, there are bubbles inside. After curing, the surface is not smooth, uneven, and looks dull and has no luster.

First, air bubbles are brought into the glue solution during the glue mixing or filling process because of the high viscosity of the glue or the wrong mixing method. If the glue solution has high viscosity, it is difficult to eliminate the bubbles. If the viscosity of the glue is small and the glue is cured slowly, the bubbles will slowly rise to the surface and be eliminated automatically. To eliminate bubbles in glue mixing and filling, vacuum pumping, heating to reduce viscosity, adding thinner to reduce viscosity or adding defoamer can be used to eliminate bubbles.
The second is the bubbles generated during the curing process. There are also several reasons for bubbles during curing: too fast curing speed, high exothermic temperature, large curing shrinkage of glue, too much solvent and plasticizer in glue are easy to generate bubbles during curing.