Nemrod 05134 tank question

[FredT]

On the Nemrod tank, does it have a thickish coating on the outside? Several tanks of that vintage had either a powder coat, epoxy or vinyl coating on them. That coating has to be removed if present before hydro and VIP. If it has an internal coating that shows ANY damage or blistering that coating will have to be removed too.

Post a photo of the tanks if you can do so.

FT

 

[Vicente]

Perhaps you are correct, sir. Perhaps this is a "Ralph Nader" sort of thing where a small number of tank explosions have been blown out of proportion. However the fact remains that however remote the danger, there are people who will not fill 6351 tanks because of their fear whether rational or not. Many of them feel quite strongly about it.

If you are filling them yourself, have at it.

Having studied engineering once upon a time, I know something of the properties of aluminum and while it has cheapness in it's favor, I'll take steel anyday.

 

[pescador775]

Vincente, aluminum alloy costs more per pound than chrome/moly steel. Production costs may be lower due to volume or other factors. I would guess that more aluminum condensators are built than steel. Corrosion resistance is one reason and makes it a good choice for compressors and scuba. Some of the compressor cans are said to be good for 80,000 cycles and I doubt that steel could do that. Problems with aluminum are human error; engineers did not know how to predict its long term properties. With experience, the selection of alloy and heat treatment has been refined to the point where modern aluminum cylinders are very good performers. My objections to aluminum are softness which makes it vulnerable to gouging, weight and bulk needed to compensate for lower tensile, and possible interactions with oxygen although that is probably not a biggie.

 

[Nemrod]

Aluminum is a gift from the gods, without it people would not fly, man would not have visited the moon, it is more expensive than steel and it is indespensible and it makes a great scuba tank. N

 

[Scared Silly]

I just did my PSI update - approx 25 million 6351 cylinders have been produced. Of these, 20 have ruptured from SLC (16 in the US, 4 foreign). How many steels have blown ?? More than 20. Also if the 6351 were as dangerous as the nattering ninnies at some dive shops say why has there not ever been a recall? Personally, the dive shops that are refusing to fill 6351 are going to lose business. If they can not compently do cylinders, then I doubt that they can compently do other things related to life support.

 

[fire_diver]

Aluminum is a gift from the gods, without it people would not fly, man would not have visited the moon, it is more expensive than steel and it is indespensible and it makes a great scuba tank. N

Alas, it is also the bane of my existance. Ok, the bane of my other passtime existance. See, when humans discovered how great AL was for EVERYTHING, EVERYTHING began to be made from aluminum. The cans you drink from, the lining of your ciggarette and gum packs. The flashing on your house, your gutters, the siding on your house too. I could go on and but I think I have demonstrated aspect 1. Aspect 2, AL has the same radio wave resonance as AU (gold). Therefore, when I go metal-detecting to find lost gold jewelry, or even gold coins, I have to dig about 3000 pieces of aluminum scrap from ever gold item I recover.

The most prolific and valueless junk reads just the same as the second most valuable and rarest of items lost. :light: Strangely, Platinum reads as iron. There has to be some cosmic joke in that.

FD

 

[Nemrod]

"nattering ninnies "

Scuba diving as a sport must collect "nattering ninnies " as a magnet to iron filings.

If we did a search for blown steel tanks I am sure there have been many more than the few aluminum but still very few in relation to total numbers and again they would have been abused more than likely. Of course, all this tells me is that both steel and aluminum tanks are exceeding reliable pieces of equipment. N

 

[oxyhacker]

This claim,that the lining MUST be removed, is often made, but I can't find any authoritive basis for it. Some sources (Global) suggest tumbling as needed to remove all rust and flaking or bubbling lining, but not worrying about removing all the lining, since the portion that does not come off easily during tumbling can be assumed to be still well bonded. This can make more sense, if the rest of the lining is in good shape, than endless tumbling or using potentially harmful chemicals to remove every last bit.

If it has an internal coating that shows ANY damage or blistering that coating will have to be removed too.
FT

 

[FredT]

I'll voice limited agreement here. There are some liner materials (the USD light blue epoxy comes immediately to mind) that is thick enough to self support and will hide additional damage under it. I've personally seen that while trying to rehab a couple of them It's also the most difficult liner to remove. Most of the thinner liners come right out. When I see blistered light blue in a tank it's dead if it's mine. They make good wind chimes though.

FT

 

[fire_diver]

Please expand on this USD epoxy. Is this something on the INSIDE of the tank? Are we talking AL or steel?

FD