Passed hydro, failed vis-galvanized

[Aigtbootbp]

I have an old steel tank that just passed hydro but was told it wouldn't pass visual because the interior is galvanized and there were a few small spots of rust. I was told due to the galvanization being compromised it couldn't be checked and therefor it fails. I personally wonder if he just didn't want to deal with tumbling a tank with a 1/2 neck.
What say y'all?

 

[Dsix36]

The inspector did you a favor by telling you the truth.

Galvanizing is a coating that is over the steel. If this coating is damaged and the steel is rusting, there is no way to check the extent of the rust withour stripping the coating off. If this were exterior on the tank (think of paint), then you could scrap it off ro make sure there was no further rust and repaint it. On the interior there is no way to remove the galvanizing around the suspect area to insure that the underlaying metal is clean. Even tumbling the tank will do no good for this.

 

[halocline]

One thing to remember is that VIS is not a legal test, it's just a scuba industry standard. Do not let the dive shop mark you tank in any way. They're not supposed to do that. If it passed hydro, it's a legal tank. The dive shop can refuse to fill it with their compressor, but they have no authority to condemn a tank.

The interior of the tank is probably not galvanized, it's probably lined with some plastic. You might be able to tumble it out. You could also try a solvent, then aggressive tumbling and cleaning. Some of the old plastic linings were notorious for being stubborn. I have never heard of a tank interior being galvanized, and that makes no sense to me.

Good luck...if you post this on the vintage forum you might get some good advice.

 

[spectrum]

As I recall the hydro test includes a visual inspection, independent of the dive shop visual and that one is a CFR requirement. As such it should have been caught at that stage before getting exercised in the test stand. I don't have the references to confirm this so those in the know, let me know if I'm all wet on this. I do remember it was hotly debated whether the hydro facility was to do this before or after pressurizing.

The dive shop visual inspection is a redundant formality when done at the time of hydro that serves to sell the sticker.

Pete

 

[regtechkidd]

Get a second opinion. This could be a novice inspector being overly conservative. Do not count on the Hydro facility doing a thorough visual inspection after the hydrostatic test. Many things can easily fall through the cracks (haha! no pun intended) when a Hydro facility is doing a large volume of cylinders every day.
If the cylinder inside is a rubber or plastic coating it will not be worthwile (or effectively possible) to remove it by using solvent, whipping, tubling, or an act of god. Once the manufacturer put that stuff on, its not coming off! If you do go ahead with an attempt to remove this coating it may cost you as much as just buying an aluminum cylinder that you wont be running into these issues with.
A dive shop employee (with a current PSI cylinder inspector certificate) DOES have the authority to "condemn" a cylinder to warn others of a potential danger that could be caused by pressurizing the cylinder. However, due to personal property laws they cannot make the cylinder unable to hold pressure. So, they can stamp out the numbers on the crown, but they cannot drill a hole in the cylinder or damage the threads.
Again, just get a second opinion.

 

[Jim Lapenta]

I have two 1/2 inch neck tanks. 72's in fact. They have not been vis'd in 2 years. Not going to get them done. I check them myself and fill them with a transfill hose. Course I don't dive them anymore. I use em on the bench for testing and rebuilding. But one of my newer ones had the coating. A shop left it on the tumbler for 9 hours with little effect. He luckily had another 72 without the coating and traded me even up to make my doubles for me. All it cost was a hydro.

 

[Gilldiver]

Get a second opinion. This could be a novice inspector being overly conservative. Do not count on the Hydro facility doing a thorough visual inspection after the hydrostatic test. Many things can easily fall through the cracks (haha! no pun intended) when a Hydro facility is doing a large volume of cylinders every day.
If the cylinder inside is a rubber or plastic coating it will not be worthwile (or effectively possible) to remove it by using solvent, whipping, tubling, or an act of god. Once the manufacturer put that stuff on, its not coming off! If you do go ahead with an attempt to remove this coating it may cost you as much as just buying an aluminum cylinder that you wont be running into these issues with.
A dive shop employee (with a current PSI cylinder inspector certificate) DOES have the authority to "condemn" a cylinder to warn others of a potential danger that could be caused by pressurizing the cylinder. However, due to personal property laws they cannot make the cylinder unable to hold pressure. So, they can stamp out the numbers on the crown, but they cannot drill a hole in the cylinder or damage the threads.
Again, just get a second opinion.

1, resin coatings can be tumbled out but you need a cutting media. A home method is to use stainless steel deck screws for cutting followed by a standard media.

2) PSI certification gives no authority to condem, mark, or damage any tank. Only a DOT certified inspector can do that.

3) I have never heard of internal galvinizing and there is no reason for internal galvinizing. I can see many problems with trying to do it.

Some spot rust is common and in no way condems a tank. Rust pitting will condem a tank and a good inspector will use a feeler probe to see if there are internal pits.

Find a new shop.

 

[captain]

There is nothing in the CFR's that require an interior coating to be removed for visual inspection. If it has spots that are flaking it can be tumbled or whipped to remove any loose coating. Rust under the coating will cause it to blister and flake, no blister or flakie area no rustie underneath.
Oh, it not galvanize it is epoxie, some were brown and some were white.

 

[Aigtbootbp]

I have looked into the tank and it does look like a coating of some sort and it is white in color. The impression I am getting from the above replies is just take it somewhere else where they are not afraid to do a bit more work (like tumbling) before condemning it.
Does this sound like a good way to go?
Oh, thanks for all the replies above, I really appreciate them.

 

[Gilldiver]

I have looked into the tank and it does look like a coating of some sort and it is white in color. The impression I am getting from the above replies is just take it somewhere else where they are not afraid to do a bit more work (like tumbling) before condemning it.
Does this sound like a good way to go?
Oh, thanks for all the replies above, I really appreciate them.

You are correct. I think what is going on is the shop just doesn't want to bother with a 1/2 inch valve tank.