lead filler "old school body work". eastwood has come out with alternative no lead filler , apperantly it is just like old school lead body work ,except no lead and you can power sand it . videos show it applys like lead filler. I have used plastics in the past, decades ago. that hurt to type! but personal choice metal body/ metal filler."the old lead sled" . SO if its a good safe metal product . that can be finished like "bondo" . win win !