Steel tanks: How much haze are you comfortable with?

[Shotmaster]

His tank might have been whipped and then not blown out. I always ask to see inside my cylinders before the valve goes back in. Even surgeons leave sponges and instruments in patients! The techs can get distracted and make a mistake. Better to be safe and inspect.

 

[Akimbo]

Ask Dr. Bill about his tank. Some rust or other foreign material clogged his first stage while descending head first. He suddenly had no air at I believe eighty feet. I'd clean the tank.

I have often considered adding cintered bronze silencer/particle filters to my tank valves... but never got around to it. The surface area of a silencer is many times that of a conical filter in a first stage so would be far less likely to clog. My thought was to take a 1/4" brass coupling with a hex plug and silver-braze it to the valve's dip tube. Of course you would have to drill a hole in the plug that matches the diameter of the dip tube. The filter would screw right into the coupling. Just be careful not to block the holes in the dip tube when brazing. I suggest blowing through the assembly before installing back into the cylinder to make sure!

1/4 Inch BSPP Sintered Bronze Silencer 60512712 - MSC

 

[halocline]

I think it's best to rinse with very hot water if you have access to it. The hot water evaporates faster and is less likely to leave a bit of flash rust.

 

[Bob DBF]

Ask Dr. Bill about his tank. Some rust or other foreign material clogged his first stage while descending head first. He suddenly had no air at I believe eighty feet. I'd clean the tank.

My take on that incident is that it was back in the day, before VIP's so the tanks were not opened before the next hydro and wet fills happened more then than now. Also the dip tube had fallen out or was not installed in his tank at that time.

The VIP was instituted to stop problems such as that and has made them a non issue today.

Flash rust is not extensive corrosion and poses no issue. As Eric said, it is a battle between good enough and his quest for perfection.



Bob

 

[andrewy]

just use evapo-rust (google). the roll it a bit. then wash with cold water 2 times, then blow with cold air. do it on cold day. or you'll hato repeat as flash rust settles fast of warm tank.

 

[Eric Sedletzky]

just use evapo-rust (google). the roll it a bit. then wash with cold water 2 times, then blow with cold air. do it on cold day. or you'll hato repeat as flash rust settles fast of warm tank.

It sounds like that's the same thing as metalprep 79.

 

[andrewy]

prob. the process is: Chelation - Wikipedia, the free encyclopedia
converts red rust to black rust. does not remove mteriAL and fast

 

[WarrenZ]

I use 4mm ceramic beads and crystal green when I do mine I try for no rust that I can see of course I am also trying to remove any other contaminants as I partial pressure mix nitrox.

 

[divealaska]

surface rust is not a disqualifying factor. Anything you do to further clean it is simply a matter of personal preference. A bigger question to me is....why are you using a steel 72? #toooldtouse

 

[BRT]

surface rust is not a disqualifying factor. Anything you do to further clean it is simply a matter of personal preference. A bigger question to me is....why are you using a steel 72? #toooldtouse

I'm betting they are using Steel 72's because they are light, negative 100cf tanks.