A grand opening celebration is planned for Monday in Fond du lac for Mercury Marine’s new 49,000 square foot EDP paint plant. The ribbon cutting ceremony will be held at 9:30 Monday morning. The plant, which broke ground in 2015, will more than double the capacity of the current facility. Company officials say its a new state of the art coating system that gives Merc engines superior corrosion and warranty protection. The expansion is part of Mercury’s investment of more than $730 million since 2008 at its Fond du lac headquarters.