I have sanded clear runs and i get tiny white flecks after sanding the run. my understanding its solvent trapped inside. Question is, how to get rid of once there. There is old clear under the new that was just scuffed with scoth brite pad. Can i keep sanding and theyll go away?

Maybe. Risk of burning through. I have had both good and bad results in fixing other painters runs with the same problem you describe. But very hard to say.

Doubtful the pop can be removed. All you can do is hope after cutting it flat and not going through like Dave stated. I 've had runs in clear for which I was responsible. I wish I was like others who never made a mistake. Most shop owners I know have made at least one error in their 20-50 years in business.

This just happened to me the other day. What a shame.