Tank Tumbling Help

[tbone1004]

@Clark Fletcher you shouldn't have to tumble or o2 clean every year if the tanks are cared for properly. That said, if that's the case, swing down to Greenville SC and I'll tumble them for you. Doesn't take very long and I only charge that you bring beer and a pizza or burgers to grill. It's a rough bill to pay. The drive might be a tad annoying, but the offer is there.

@UCF both wet and dry. If I'm really trying to cut rust, I'll dry tumble for several hours, rinse the tank and media really well, then put the media back in with some diluted simple green and electric kettle temp water for another couple hours. That is a SUPER rare occurrence and usually only when I buy used steel tanks.

The GMC cycle is something like run with the glass beads and the compound O for however long, rinse for 5 seconds then immediately dry so you rinse the excess off but leave a light film in there for rust protection. It's too much effort for me so I usually just go immediately from big rinse to dry.

 

[JamesBon92007]

@Clark Fletcher you shouldn't have to tumble or o2 clean every year if the tanks are cared for properly. That said, if that's the case, swing down to Greenville SC and I'll tumble them for you. Doesn't take very long and I only charge that you bring beer and a pizza or burgers to grill. It's a rough bill to pay. The drive might be a tad annoying, but the offer is there.

@UCF both wet and dry. If I'm really trying to cut rust, I'll dry tumble for several hours, rinse the tank and media really well, then put the media back in with some diluted simple green and electric kettle temp water for another couple hours. That is a SUPER rare occurrence and usually only when I buy used steel tanks.

The GMC cycle is something like run with the glass beads and the compound O for however long, rinse for 5 seconds then immediately dry so you rinse the excess off but leave a light film in there for rust protection. It's too much effort for me so I usually just go immediately from big rinse to dry.

What exactly is "electric kettle temp water?" I have used boiling water in a pan to rinse my tanks after whipping them and had good results. Does that sound about the same?

I have one old Sportsways tank that whipping didn't quite work on so I'm thinking that tumbling is my best option however I'm not completely clear on what to put inside. Things like "glass beads" and "pea gravel" have been mentioned. Some glass contains lead. How do you know which beads to use? Products such as Simple Green is being tossed around as though everyone knows what it is but I've never used it. Is there a specific type that I should use? Pea gravel might be a good choice because I have some on hand.

I have one old steel 72 (from the 60s) that I had tumbled after it's last hydro (2011). I removed the valve and looked inside and it is beautiful! Nice and clean and shiny. I'm convinced that tumbling will restore my old Sportsways tank. I'm sure I have enough motors and pulleys laying around that I could come up with 25-50 rpm. How long is a tank usually tumbled for?

 

[BRT]

I'm following this thread with interest because I've been thinking about tumbling my own tanks this coming winter.

I'm planning to dry them with nitrogen. Nitrogen is cheap.

I just cleaned 2 with a whip, rinsed them and used nitrogen to dry them.

 

[Clark Fletcher]

@Clark Fletcher you shouldn't have to tumble or o2 clean every year if the tanks are cared for properly. That said, if that's the case, swing down to Greenville SC and I'll tumble them for you. Doesn't take very long and I only charge that you bring beer and a pizza or burgers to grill. It's a rough bill to pay. The drive might be a tad annoying, but the offer is there.

Thanks @tbone1004. I actually end up passing through Greenville on my way the Seneca/Clemson area for work several times a year. Regardless, it's not that bad a drive for me. Again, I don't know how much my LDS charges just for inspection and O2 cleaning. My tanks were just inspected and cleaned in April. Another dive shop brought the tanks to my LDS for tumbling/O2 cleaning with no valves in them. However, my LDS knew the other shop was wanting to get out of keeping steel tanks on hand. Don't know if I paid too much but, I bought both tanks, inspected, tumbled, O2 cleaned, new valves, filled with EAN32 for $500. They have two years left on the current hydro. How much of that was tanks and valves and how much was tumbling and cleaning, I don't know.

Anyway, thanks for the offer. I may take you up on that down the road.

 

[TrimixToo]

What exactly is "electric kettle temp water?" I have used boiling water in a pan to rinse my tanks after whipping them and had good results. Does that sound about the same?

I have one old Sportsways tank that whipping didn't quite work on so I'm thinking that tumbling is my best option however I'm not completely clear on what to put inside. Things like "glass beads" and "pea gravel" have been mentioned. Some glass contains lead. How do you know which beads to use? Products such as Simple Green is being tossed around as though everyone knows what it is but I've never used it. Is there a specific type that I should use? Pea gravel might be a good choice because I have some on hand.

I have one old steel 72 (from the 60s) that I had tumbled after it's last hydro (2011). I removed the valve and looked inside and it is beautiful! Nice and clean and shiny. I'm convinced that tumbling will restore my old Sportsways tank. I'm sure I have enough motors and pulleys laying around that I could come up with 25-50 rpm. How long is a tank usually tumbled for?

Get some tumbling media. For steel, that's aluminum oxide chips. This media lasts about three days past "forever," and will leave a uniform grey matte finish (not a shiny one). I have never seen a steel tank shiny inside, but aluminum will be shiny after being tumbled with the right (ceramic) media. Simple Green is a common household cleaner. You want the kind without added scent, which is called Crystal Simple Green. You can also get Global cleaner from, say, NESS, but Crystal Simple Green is probably less expensive.

If you have a clean tank hydroed, it should take 30-60 minutes to clean it up using the right media. If it's got more rust, you will have to tumble longer. Open it up, pour out the media, look inside, refill, retumble, repeat until cleaned up. After a while you'll get tired of that and just guess high on how long to tumble (some pretty rusty ones I have tumbled for 4-6 hours). After that, there will be lots of dust, rust, and steel particles, and the tank must be rinsed. If if will be used in oxygen service (including partial pressure blending) it must be O2-cleaned. In both cases, a gallon of rust inhibitor will last you a Long Time. If you follow the directions, using it should not allow flash rust to re-form in the time it takes to dry the tank using forced hot air or very dry (that is, breathing) air.

Don't forget to clean and rebuild the valve.

NESS's tumbling page is here: Tank Cleaning

 

[NAM001]

Any respectable care for the tank should eliminate the need tfor tumbling. I use a whip on mine. I dont want to remove teh coating in the inside of the tank. Yes it has a coating it is a hair thin white coating not the thick plastic coating stuff of decades gone by. A little flash rust has never hurt any one. The flash will be on the coating and comes off fairly easily. You dont want steel exposed to the gas if you can get around it. After I whip and clean with a anti corrosive like mentioned earlier. I fill to 500 and vent 3 times to insure the RH is now compressor dewpoint quality. It removes any moisture in the tank that went unseen prior to putting the valve on and it removes the moisture in the air that was in the tank before putting the valve on. One 3-500 psi fill and vent is probably good enough but I do 3. At that point i know the only air in the tank was from the fill system. Many may feel it is unnecessary but our humidity is in hte 90's so much of the time. fill to 300 psi will dilute the contents by a factor of 20 . the 90% humid air in the tank is reduced to about 4% do it again and it is well below 1% and again it is probably no different than fill system output of .1 or .2%. That is not much moisture to cause rust. That should be a dew point well below -50 and closer to -80 or so.

 

[The Chairman]

The homebuilt used tumbler

I want to see pics and a good description!

 

[2airishuman]

I fill to 500 and vent 3 times to insure the RH is now compressor dewpoint quality. It removes any moisture in the tank that went unseen prior to putting the valve on and it removes the moisture in the air that was in the tank before putting the valve on. One 3-500 psi fill and vent is probably good enough but I do 3. At that point i know the only air in the tank was from the fill system. Many may feel it is unnecessary but our humidity is in hte 90's so much of the time. fill to 300 psi will dilute the contents by a factor of 20 . the 90% humid air in the tank is reduced to about 4% do it again and it is well below 1% and again it is probably no different than fill system output of .1 or .2%. That is not much moisture to cause rust. That should be a dew point well below -50 and closer to -80 or so.

I evacuate the cylinder with a vacuum pump after removing the valve for any reason.

 

[tbone1004]

@JamesBon92007
tea kettle water is basically boiling water so that works. Just a convenient way to get hot water.

Simple green is a normal cleaning product that was around in my house for as long as I can remember. It's a brilliant degreaser and it's in home depots/lowes/walmarts etc. so easy to get a hold of.
Simple Green 1 Gal. Concentrated All-Purpose Cleaner-2730103613005 - The Home Depot
Crystal is a bit easier to rinse out, so may want to go there. One gallon of this stuff lasts a LONG time.
https://www.amazon.com/dp/B000ULLGRU/_encoding=UTF8?coliid=IWEUBO0OX3GWZ&colid=1F0GOGJ0MWXFR
Blue Gold is about $40/gallon direct from them for reference.

for cutting rust out, you can just use normal pea gravel. I'd rinse it real well before you put it in there to get any dirt off but it's fine. Aquarium gravel works well too. You don't want to use glass for rust cutting since it isn't aggressive. You'll have the tank on the tumbler for several days before you get any meaningful progress. I usually dry tumble when I need to cut serious rust. I'll leave it dry tumbling, then rinse everything out, and then wet tumble for about an hour with the cleaner in there. Dry tumble is more aggressive and will cut through all of the nasty stuff faster, then rinse all of the nasties out including a good wash of the media, then wet tumble for a nice finish.
Vigoro 0.5 cu. ft. Pea Pebbles-54255 - The Home Depot

Tanks are tumbled for as long as they need to be. You can't really "over tumble" a tank, so when they're really bad I'll usually leave them on over night. Typically about 3 hours is enough for most tanks.

@KWS I don't believe PST has any finish on the inside. I know Faber does, but I seem to remember that PST didn't for some reason.

 

[NAM001]

I evacuate the cylinder with a vacuum pump after removing the valve for any reason.

That i guess would work but few have the assetts to do it that way, especially when the deed is done after the next full fill anyway.