Galvanized versus Painted Steel tanks

[Florabama]

So, who would be the best current manufacturer of hot dipped galvanized tanks? The only steel tanks I've ever owned were either old 72s with a "Scuba Pro" sticker on them or my painted Fabers.

 

[Florabama]

Not trying to start a debate, but I found this on Dive Rite's site, and I would appreciate your comments.

Tank Paints, Coatings, and Finishes
Standard aluminum tanks are available in a very wide range of colors. Steel tanks and the smaller aluminum tanks (i.e., less than 50 cu. ft. in volume) are often available only in a very limited selection of colors. At any given time, the availability of specific colors on specific sizes is very erratic due to relatively small production runs.
With aluminum tanks, it seems that most coatings do more to encourage corrosion than to prevent it. Paint on aluminum tanks just does not seem durable and does not adhere well, often peeling and flaking. Once water makes its way under the paint, corrosion is actually encouraged. The opaque paint colors hide any corrosion that might be occurring underneath the paint. Aluminum tank manufacturers have attempted to address this by offering clear-coat and translucent colors that allow the corrosion to be visible, but our experience has been these finishes seem to really promote even faster corrosion. Ironicly, the most popular paint color for tanks is "Yellow", yet this seems to be one of the least durable paints, beginning to peel and flake with even limited exposure to saltwater. The aluminum finishes of choice have become brushed aluminum or what is termed "shot blast," which is an unpainted bare metal surface that has been textured and is a uniform dark gray. The unpainted finishes hold up very nicely and do not encourage or hide corrosion.

Uncoated steel tanks quickly develop a coating of rust in the presence of water, so all steel tanks are coated. The most durable coating for steel tanks is galvanized. When a steel tank is galvanized, a zinc metal coating is bonded to the surface of the steel. The hot-dipped galvanized coating comes from the factory as a shiny silver color that rapidly ages to a mottled gray once exposed to sea water. Some experts believe that environmental concerns about the zinc galvanizing operation itself outweigh the benefits of hot-dipped galvanization. Our hydrostatic test facility operator is of the opinion that hot-dipped galvanization is the root cause of the higher rate of hydro failures in those tanks. Steel tanks are also available in a durable and environmentally friendly cold-galvanized coating that is further protected with an epoxy paint that seems to adhere very well.

We have observed heated debates over the corrosion resistance and durability of hot-dipped galvanized steel versus cold-galvanized painted steel tanks. In fact, we have seen steel tanks of every type and manufacture in excellent condition after many years of heavy service and we have also seen them fail the first annual inspection. The truth is both types of steel tanks will give many years of corrosion free service when they receive proper care. All tanks must be thoroughly rinsed in fresh water after use in salt water and during storage the boot should be removed. Both unpainted and painted steel tanks require some additional care in comparison to unpainted aluminum. Any deep gouges or scratches that cut through the galvanizing and expose bare metal need to be touched up with either a rust-inhibiting paint or a cold-galvanizing compound, both available in aerosol sprays and brush applicators at hardware stores.

He doesn't explain why he believes this, and what environmental concerns is talking about?

http://www.diveriteexpress.com/library/tanks.shtml#manufacturers

 

[spectrum]

The one with the most history in the scuba market and nicest initial appearance is PST. Once they picke in ocean water they are said to be comparable. They are in financial hot water and while they existing cylinders don't seem destined to land on the scrap heap it's hard to say what the future of the brand will be.

The more viable cylinder in terms of long term manufacturer support with comparable specs is the Wothington sold under the XS-Scuba and Sea Pearles brands. they introduced the line last fall and are coming on strong with attractive pricing.

I may be missing something but it seems that all or most of the hot dipped actiion is in HP (3442 PSI) cylinders.

I have 6 PSTs and they are holding up very well. All things considered I'm not sure what I would buy today of the I had "identical" products from each manufacturer at the same $$ sitting in front of me. Depending on what size you want PSTs inability to supply the market may make a Worthington a no brainer.

Pete

 

[spectrum]

Not trying to start a debate, but I found this on Dive Rite's site, and I would appreciate your comments.



He doesn't explain why he believes this, and what environmental concerns is talking about?

http://www.diveriteexpress.com/library/tanks.shtml#manufacturers

I'm not knowledgable enough to be specific but my experience around metal plating/finishing operations in general is that the vapor emmisions, liquid and solid waste are very hazardous and in general evil. It is very difficult to open a facitity to perforn this sort of work due to enviornmatal restrictions and requirements. That being the case there will be folks with strong enviornment and worker safety inclinations who seek to discourage the practice. Many such facilities became superfund sites.

Pete

Pete

 

[Florabama]

Thanks Spectrum, very good information.

 

[dl348]

Thanks everyone, for all the good information. Who makes the best galvanized tanks?

Now, I would say Worthington. We have 4 of them, they're great and they came with the Thermo convertible valves.

 

[Scotttyd]

In your guys opinion is a hot dipped galvanized HP 130 worth an extra $35 over a faber painted tank of the same size?

 

[mike_s]

In your guys opinion is a hot dipped galvanized HP 130 worth an extra $35 over a faber painted tank of the same size?

I have painted fabers with nothing wrong with them..


But given the choice of a 'hot dip galvanized' for $35 more, I'd spend that $35 bucks.

 

[TechBlack]

spend they extra $35, it'll be well worth it in the long run, i've seen condemned painted steels after 6-7 years!

 

[Luis H]

I agree with Captain above…Personally, I would never pay money for a non galvanized steel tank (or at least very unlikely).

Take a look at the pictures in this thread:
http://www.scubaboard.com/forums/tanks-valves-bands/229408-tank-boot-x-series-tank-question.html