Old new tanks?????

[amnstoner]

Situation: I saw an add that was posted by someone getting out of diving and inquired about what he had for sale. He was selling 4 steel 72's and two AL 80's. The tanks were manufactured in (Steels-1972) and (AL-1986).

Questions: I know I am going to have to get these tanks current with new hydro's and Viz's and add new valves. (they came with the latest and greatest in J-valve technology)lol. Can I do anything to improve the apperance of these tanks. I would like to strip them down and re-paint, coat, galvinize????? these tanks so they look better as well. What are my options and what type of coatings can be used on them?

Thanks in advance,

OBTW I got the 4 steels for $100.00 and AL's for $45.00
Picasa Web Albums - Austin - Scuba Stuff

 

[divestoclimb]

The tanks can be repainted but you can't use heat to dry them (especially not the aluminum ones).

Keep in mind that the Aluminum tanks are old enough that you may find shops which are unwilling to fill them. This was due to a neck cracking issue on a specific alloy of Aluminum that was used at the time those tanks were manufactured (even if your tanks don't have the issue or are even not of that alloy, some shops will still refuse to fill them).
You should ask around before putting too much money into hydroing and VIPing them--if you realize it won't work out the good news is you can recycle Aluminum 80's for about $6-8 each. Also, a good shop that rejects your tank should offer to sell you a new one at a decent price so you may be able to work them towards a discount on new ones.

You don't have to replace the valves as long as they still work (and depending on what the VIP guy says about their condition). Just keep the reserve valve open all the time and you'll be fine.

 

[deepstops]

Keep in mind that the Aluminum tanks are old enough that you may find shops which are unwilling to fill them. This was due to a neck cracking issue on a specific alloy of Aluminum that was used at the time those tanks were manufactured (even if your tanks don't have the issue or are even not of that alloy, some shops will still refuse to fill them).

Catalina Cylinders never used the 6351 alloy so if the shop automatically rejects a Catalina tank on that premise, you need to find another shop anyway.

Boycott stupidity

 

[DoubleHoseDiver]

You can use ZRC Galvilite to "repaint" the steel tanks with. Captain told me about this stuff and have read that it is really good stuff, but I haven't used it yet. As for the alum tanks, I wouldn't bother with them....to old and I never like alum tanks. I hope this helps. Happy Holidays, Tim

 

[Ed Palma]

My thoughts:

1. Stripping the tanks is best done with a chemical stripper that is suited for the type of metal. Abrasives should be used sparingly - if at all - to prevent any further loss of material.

2. A viz should be performed before any work. Wh waste time and effort re-finishing tanks that might fail? Check for internal corrosion. Importantly, for the aluminums, check the shoulder markings: Who manufactured it? Does it carry the stamp SP6498? This means it was made of the alloy that has been implicated in sustained load cracking or SLC. A lot of shops (as deepstops said) will refuse to fill these tanks even if they pass eddy-viz and hydro. You can argue till you're blue in the face, but they're the one with the air, and you're the one with the dollars, so do as Deepstops said, and take your tank elsewhere.

3. If the valves work, why change them?

 

[amnstoner]

The J-valves do work, If the tanks do pass hydro and viz I wanted to change out the valves for peace of mind.

 

[mkutyna]

As long as the j-valves are cleaned and working correctly, there is no safety issue with using them. New valves are not cheap.

 

[amnstoner]

Any suggestions on what type of chemical stripper to use... IE brand name and where it can be purchased.

 

[Jimmer]

Speaking from experience dealing with stripping/re finishing tanks. I'd leave those unless there was noticeable rust or paint bubbling. They look pretty good in the photo!

 

[Gilldiver]

Any suggestions on what type of chemical stripper to use... IE brand name and where it can be purchased.

Any stripper, like Zip-Strip, from Home Depot that has Methylene Chloride in it will strip just about anything and is safe on steel or aluminum. Look at the lable to see if it is there.

Now, Methylene Chloride is not safe for you - strip outdoors and use Nitrile or Viton gloves. Home Depot should have then somewhere near the strippers.

Do Not use the paste strippers that use a paper to help pull off the paint. These are mostly Sodium Hydroxide based which can etch the surface.