Cleaning new tanks

[justin]

I've got a couple new tanks here. I've been trying to clean them before passivating but I can't seem to get them clean. Long hot caustic cycles, detergent, and manual wiping as far in as my arm will go. The manway is small and designed in a way that is difficult to get through. I'm still getting a grey residue on a clean rag after I wipe. Any advice?

[BH Tavern]

Same exact issue on new tanks. Did you ever have any luck?

[AMS0286]

Degreaser

We recently took delivery of a 7 bbl FV with the exact same issue. It seems like it's polishing compound, and oil/grease like. It was really only present around the area where the cone meets the side wall. After discussing with other local brewers, I went the way of degreaser (we used simple green clear) through a cip cycle. That seemed to tame it for the most part, but the only thing that was really successful was manual scrubbing while the surface was wet with degreaser. Obviously the tank was well rinsed and run through another caustic cycle followed by acid # 5. Let me know how yours turns out, and also I would love to hear how anyone else deals with this issue as I've got another tank coming in the very near future.