El Dorado lead lined frames are manufactured from cold rolled 16-ga steel. 14-ga and 12-ga are available upon request. We offer either fully welded frames or knock-down frames although knock-down frames are not recommended for use with pivot hinges. Frames shall be suitably reinforced for closers, brackets and all other surface applied hardware. Drilling and tapping of surface hardware to be done in the field by the installer. Frames are painted with a coat of rust inhibiting primer paint.