DETROIT—More than 1,000 new vehicles and parts that were moving down production lines when the power went out at more than 50 North American car plants in August have been scrapped due to quality concerns resulting from the process stopping in midstream.

According to an August 22, article in the Detroit Free Press, cars and trucks were left half painted, in some cases soaking in chemicals, robotic welding arms left some joints only partially joined, engines being sculpted by precision laser tools were left incomplete and many parts were simply dropped on the floor when the vacuum-powered suction arms that lift and move them lost their hold, the paper said.

When power was restored, Detroit’s carmakers had to deal with effects of the outage on manufacturing operations. The paper said the automaker couldn’t simply “flip a switch” and finish the work on the line if they wanted to guarantee a quality product. Though much of the work-in-progress was saved, some was not.

“If you’re in doubt, throw it away,” was the post-blackout motto at Chrysler Group, senior vice president of advanced manufacturing, Frank Ewasyshyn, told the Detroit Free Press.

He estimated that Chrysler AG lost production of 10,000 vehicles during the power outage, and an undisclosed part of that was from cars, trucks and parts that had to be discarded. No financial estimate of the loss was available, the paper said.

The report said that Ford and General Motors, which did not provide numbers, experienced similar situations.

The car makers told the newspaper that paint shops took the biggest hit because, in that section of the plant, hundreds of vehicles travel through multiple stages of chemical dips and sprays with oven drying in between. The process is closely timed, and the temperature and humidity is tightly controlled, so that the paint correctly adheres to the metal.

The power cut left some parts soaking in chemicals that may have damaged the metal, while some had dried halfway painted, compromising the integrity of the overall finish.