Tank tumbling hell.

[MattK911]

I am at a complete loss at my experiences over the last 2 days. Hopefully someone can shed some light on the nightmare that my new (to me) pst 104's have been.

I will start from the beginning. After months of searching I purchased a set of 1978 PST lp104's. I broke them Down and inspected the insides and was very excited when they looked almost new. I send them off to Hydro and they return with quite bit of flash. So I decide to tumble them

-ROUND 1-
I threw them on the tumbler as I had done before with many other tanks. I used aluminum oxide and a solution of simple green crystal. I drain, rinse with hot water, and treat with GMC Compound O. I then dry with hot air. They flash almost as bad as before.

-ROUND 2-
So I go through the ordeal, this time with a longer rinse of a stronger Compound O solution. Dried with hot air. Results identical.

-ROUND 3-
I decide to do a 2 hour tumble as it’s only flash. Same process, but instead I use compressed air from our shops air banks to dry faster. Well you have probably picked up on the trend.

-ROUND 4-
It is now 3AM. This time I bring out the big guns. Same process as before but instead of using air to dry I use helium (it was lying around). And it was better, but still flashed bad. I call it a night, refill the tanks with media and tumble until the next morning.

-ROUND 5-
Severely annoyed I return to the shop after an overnight tumble and rinse, compound O, and hot air dry. Results are the same. I decide to just whip the flash out and live with it.

I have tumbled quite a few tanks working at a shop. I’ve had tanks with light flash to tanks I thought were lost causes and have never had as frustrating as an experience as this. Of course it’d be on my personal tanks.
My tanks have also begun to play tricks on me. I have a PST steel 72 (same year as my 104s, and without a liner) that has been sitting in a corner in the shop without a valve or plug for over a year. It doesn’t have a spec of rust. After waving the white flag on my 104’s I decide to tumble the steel 72 exactly as I had my 104's, but did not treat it with compound O, and left it to drip dry all day. There was one teeny spec of flash rust. I feel like I am losing my mind.

I apologize for any grammatical errors, it’s been a long day to say the least.

 

[runsongas]

have you tried omitting the compound O with the 104s?

 

[OTF]

Oh god the thought of using helium hurts to think about. Guess it makes sense from a chemical perspective.

 

[Scared Silly]

If light flash why wet tumble at all??

 

[ScubaBunga]

I rarely wet tumble as it does seem I get more flash and it’s also a huge pain. Generally dry tumble, use really hot water to rinse, and tank air to blast dry, rarely have any rust, not even small spots. I’ve also just whipped and blown out tanks too. Hopefully that works for you and maybe next time it will somehow be better. Good luck.

 

[akdeepdiver]

Try dry tumbling, rinse with hot distilled water mixed with 1 to 2 cups isopropyl alcohol, then dry with compressed air or a cylinder dryer. The Alcohol will help break up any surface tension allowing it to evaporate quickly and also leaves no residue.

 

[captain]

I use a 15" length of 3'/8 tubing with a tee on one end and 2 valves. One valves connects to the hot water in my service sink, the other connects to air from my compressor. After tumbling I invert the tank with the tube in it, turn on the hot water, let it rinse until the tank is too hot to touch, turn off the water turn on the air. Vola, dry tank with no rust in less than 2 minutes.

 

[MattK911]

:UPDATE:

I couldn't leave well enough alone. Went to the store and got isopropyl alcohol and distilled water while I put my tanks back on the tumbler.


:ROUND 6:

While tumbling heat up distilled water in microwave. Fill 5 gallon bucket.

Make a mixture of isopropyl alcohol and water with 1 gallon of hot water. Set aside.

Empty tank of media and rinse using tank rack.

Turn back right side up and fill with 5 gallons of hot distilled water. Cap and swish around to heat the entire tank, then drain.

Pour isopropyl alcohol mixture into tank and drain immediately. Stick cut off low pressure hose into tank and blast for 15-20 seconds.



It worked perfectly, My tanks are now beautiful inside.

Thanks for everyone's help. I'm going to sleep great tonight.

 

[happy-diver]

I use a 15" length of 3'/8 tubing with a tee on one end and 2 valves. One valves connects to the hot water in my service sink, the other connects to air from my compressor. After tumbling I invert the tank with the tube in it, turn on the hot water, let it rinse until the tank is too hot to touch, turn off the water turn on the air. Vola, dry tank with no rust in less than 2 minutes.

Multiples of Magnificence!

 

[Compressor]

Excuse my ignorance but does flash rust require tumbling?