I have a steel cylinder with flash rust from the last hydro. Has two gallons of evapo-rust in it.

[Rusty Shackleford]

Prepping it for the next upcoming hydro. I am trying evapo-rust to undo AirGases fu*k-up. I dove it for five years with some flash rust.I am shaking it periodically and indexing the cylinder about 30-40 degrees every few hours.

I am using Evapo-Rust for the prep, then I will clean it and used some O2 compatible rust preventer I purchased from Northeast Scuba Supply.

How should I clean out the traces of Evapo-Rust in between? Dawn or Simple Green? Or lots of water?

 

[HKGuns]

Evapo-Rust is miraculous at killing rust. Great choice.

 

[Rusty Shackleford]

It was just a few thin streaks of flash rush, tumbling seemed like an over-kill option. I only need to make sure I properly de-con the cylinders prior to applying the rush inhibitor and shipping them off to the hydro tester.

I have two more 95's in the same boat I am going to prep in the same manner. The great thing about Evapo-Rust is it's reusable many times.

 

[dead dog]

From Amazon Questions:

Question:
Will this be safe to clean steal scuba tank in side and help prevent rust

Answer:
I'm a dive master and certified tank inspector. If you have rust in your tank you should have it professionally inspected. You "could" use this but if there is pitting or other dammage it would cripple the tank and potentially make it unsafe to fill. Not sure about any residue this might leave that could contaminate the air, so I would say probably better stick to tumbling to remove light rust. Your dive shop can do this or should know of a service center that can. see less
By M Squared on November 1, 2017

As a diver from a family of divers, I just want to underline the importance of what M Squared said. Take your tank to someone who does inspections and hydro-stats, and let them deal with this issue. Scuba tanks are a powerful bomb and they have killed a lot of people. An improperly serviced scuba tank is a bomb ready to go off because you looked at it the wrong way. Tank maintenance is not the place to experiment or save money. Let a pro tumble the tank and determine if it is still safe to use. It is some of the best inexpensive life insurance on the market. Diving is dangerous enough without short cutting equipment maintenance. While I am on the subject, those of you who took a three day resort "diving course" and think you are safe to dive - you aren't. Go get some real training that drills things into you until you are instinctively making the right moves, even when you are scared, disoriented, and your gear is acting up. Enough said. see less
By rwizard on February 20, 2018

 

[runsongas]

lots of hot water, although for flash rust, dry whipping should be enough and is a lot less effort

 

[happy-diver]

I made a whip from some stainless braided wire aluminium tube and a clamp
You can clamp a wire brush in an aluminium tube for a drill too
Almost boiling water to aid in evaporation for me

 

[rjack321]

It was just a few thin streaks of flash rush, tumbling seemed like an over-kill option. I only need to make sure I properly de-con the cylinders prior to applying the rush inhibitor and shipping them off to the hydro tester.
.

Why are you bothering to remove flash rust before getting them hydroed?

 

[AfterDark]

Why are you bothering to remove flash rust before getting them hydroed?

Better yet why didn't the last hydro tester take care of the rust 5 years ago post hydro? I wouldn't accept a rusted tank post hydro, hey buddy your job is not done yet!

 

[Rusty Shackleford]

Because the last hydro tester was incompetent.

 

[AfterDark]

Because the last hydro tester was incompetent.

Well you shouldn't have paid and accepted the tank. I always take my tanks to the LDS to have them rolled it to remove rust. I would advise anyone to do the same.