Hello Joe;
I understand where you are coming from Joe. There are no cleaning requirements in D1.1-2010, Clause 3. However, Clause 5.15 contains language that allows a thin rust-inhibitive coating (primer paint?).
My position is that while Clause 5.15 permits the primer, it isn't necessarily prequalified just because Clause 5 permits it. A good example of a similar situation permitted by Clause 5, but where the requirements of prequalification are not met would be for groove welds made with backing. Clause 5.10 allows for the use of copper, flux, glass tape, ceramic, or steel backing, but only the use of steel backing is prequalified (ref. 3. 13.3). If the contractor wishs to qualify the procedure with the primer intact, he is free to do so. If the procedure passes, he is free to use the primer that will be welded in production.
Best regards - Al