excavar

The sentence:

Se calienta la plancha hasta que el polvo se cristaliza y se adhiere a la superficie de la matriz y se introduce en la solución de ácido, que excava alrededor de los granos de resina.

My attempt:

The plate is warmed up until the dust is crystallized and it adheres to the surface of the matrix and it is introduced in the acid solution, that scrapes around the resin grains

Hello solfinker,
Do you need help with the translation of the word "excavar" only or you need to check if the whole sentence is ok?

Hello!
Let's say that the doubt is - in my case - the title of the thread. But I always try to take advantage of your skill to correct the full sentence. I thank you whatever the help.