Worthington LP7-77 vs Alum 80

[Rainer]

A real issue is when the tank is rolling around and gets a plenty of scratches on an exterior over time, specially in the SALT water environment. I don't think it will matter on the fresh water though. HDG lasts long in any circumstances.

You don't seem to have a very good understanding of how painted galvanization works. Even with scratches, rust won't spread. That's the entire point of the process. You can also buy galvanizing paint to patch up any scratches you'd find. While I, too, rather have HDG cylinders, your post suggests you're missing something.

 

[Hoosier]

Thanks.

More than enough to understand a cold galvanize tanks.

I had a chance to inspect several old cold-gavanized Ashai tanks during VIP course.

A cold-galvanized tanks can get chips in the finish and start to rust.

The spray galvanizing is sort of a zinc-based paint, and doesn't properly bond to the steel like hot-dip. It chips easily and you have to keep patching up your tank's finish.

That is the reason why HDG is preferred.

Nobody doubts that a good maintenance will save any tank's life time. But, we are talking about a likelihood here.

 

[crpntr133]

A $10 can of ZRC spray will do wonders for CDG tanks. I know it isn't the same as HDG but it works. Personally I would rather have HDG.

 

[Hoosier]

A $10 can of ZRC spray will do wonders for CDG tanks. I know it isn't the same as HDG but it works. Personally I would rather have HDG.

Like I said, it won't be any issue in the fresh water environment where we dive mostly...

 

[rleslie]

To me this comes down to the cost difference between HDG & CDG. It's really not that big of a deal to inspect the CDG tanks ocassionally and touch-up any spots that may have been scratched. Actually, wouldn't be a good idea to do the same with HDG tanks? In a salt water enviro, the tank can also be rinsed while the rest of the equipment is rinsed.

Roger

 

[Luis H]

Yes, you should always rinse your tanks. But, if they were not galvanized they would rust anyway.

I have about 16 steel HDG tanks, a couple are late 50’s most are 60’s or 70’s. Only one of my tanks has shown any raw steel. Even then there was no rust; I am assuming it’s due to the zinc protection. I wire brushed it and used galvanizing paint.

I do use galvanizing paint on some tanks under the boot, but just for extra protection.

CDG sounds acceptable, but HDG is definitely the best long term protection for salt water divers.