1) This new release covers the removal of bright dip from the description as an allowed process for cleaning Alum. The replacement is to chemically clean / etch by acid and / or caustic processes the parts and weldment's.
2) It also clarified the surface finish call-out on sheet metal as 32 micro-inch (Ra) and the exceptions allowed, section 4.9
3) It also clarify's the use of electropolish for Alumimun (internal note - refer to new vendor list)
Calum Torrie