Tumbling residue- how to remove?

[duckbill]

I just finished tumbling my first cylinder. The cylinder is steel, and the media was aluminum oxide tumbled dry. I really liked tumbling it dry as the media just poured out of the small 1/2NPT opening as though the cylinder was an hour glass.

However, even with a very agitated rinse, there still seems to be some dust residue sticking to the interior wall. Any ideas on how to make a clean finish on the job?

I've considered whipping it while about half filled with water before rinsing and drying (though the whip is never able to clean the top few inches and shoulder at all). I've heard of some using Sinple Green for something, perhaps to get rid of the residue(detergent isn't cutting it)?...but I've also heard that Simple Green is mildly acidic, and I don't want anything that may aggravate flash rust. And I don't have time to order inhibitor at this point, so I'm hoping to hear some good, old methods maybe used back in simpler times.

Thanks.

 

[DA Aquamaster]

I rinse my tanks after the tumble until the rinse water is not noticeably dirty, then I scrub the valve threads with a plastic brush and tumble the tank with either simple green (not may favorite - takes more rinsing, and you need to rinse until the odor is gone), or simple green crystal (much easier to rinse), or about a 30/1 mix of blue gold cleaner (my favorite as it is easy to rinse and has a rust inhibitor).

5-10 minutes on the tumbler followed by cold water rinse leaves things residue free. A good way to ensure you have fully rinsed the tank is to catch some of the water draining out of the tank in a clear water bottle, put a lid on it and shake it - if you have any suds, you need to rinse a little longer. If it's suds free you can stop.

I then invert the tank and blow the tank dry with a rubber hose attached to a first stage regulator and a tank of air.

I don't have issues with flash rust with this approach with either simple green or blue gold.

 

[duckbill]

Thankyou. Is this Blue Gold Cleaner a common shelf item at retail outlets? I've never heard of it. Locally we have Orchard Supply, Walmart, Lowes, Home Depot. Do you know if any of these are known to sometimes carry this product, or is it pretty much a mail order item?

I dry the same way you do. Cold water rinse and periodic purging via a reg on a hot cylinder while the cylinder walls are heating in the sun. I get a light golden tint, but never any orange or red. Today the temps were over 100 degrees, so it dried very nicely, to say the least.

 

[DA Aquamaster]

I've never seen blue gold locally. The odds are a little better with simple green crystal, and of course simple green is everywhere.

I dry the tank in one long blast of air - maybe 25 cu ft. There are pros and cons to heat. It does dry the tank faster, but it also speeds the oxidation process, so it's zero sum game. The best defense against flash rust is very rapid drying at cool temperatures.

 

[duckbill]

Thanks. Until I can get ahold of something better to use, I figure if I whip it during the rinse with a bit of detergent, then anything that is still stuck to the walls after that isn't going to come off during fills and use.