we installed a select and better birch hardwood floor.we were advised to finish the floor with varathane waterborne poly. we applied 5coats succesfully. a bottle of windex hand spliied on the floor and was unnoticed for a day. the windex went through the poly and has made a terrible stain. it has also made the wood to shrink. we are veery dissapointed and need some help. should this have happened and what can we do to correct the problem?