Discovery Channel Episode shows how tanks are made

[Ed Palma]

Yeah, I'll grant that...

The video shoulda ended before they showed the painting process... I think aluminum tanks should look like aluminum

 

[SparticleBrane]

I refuse to buy painted aluminum cylinders. Only brushed aluminum for me.

 

[codecruncher]

I can see how maybe you could reason the sanding and painting and heat baking don't affect the tank much after the initial hydro.

But I'm surprised the DOT agrees with that. It is the Federal Govt after all and when does reason enter that picture?

So this means at any time I'm ok to do a similar process to my tank without immediately being in violation of some DOT hydro rule?

When I take my PSI VIP course in the next year I'm going to bring this one up as a question.

 

[fire_diver]

I can see how maybe you could reason the sanding and painting and heat baking don't affect the tank much after the initial hydro.

But I'm surprised the DOT agrees with that. It is the Federal Govt after all and when does reason enter that picture?

So this means at any time I'm ok to do a similar process to my tank without immediately being in violation of some DOT hydro rule?

When I take my PSI VIP course in the next year I'm going to bring this one up as a question.

The DOT allows the manufacturer to do it becuase they know what procedures, chemicals and temperatures are being used in the plant.

I doubt you will harm a tank by NORMAL sanding, or paint stripping. Try to bake it, and you better keep that bomb away from me!

FD

 

[Ed Palma]

Okay, okay. But what I don't get is why they couldn't just flip the process and do the hydro after the sanding and painting?

 

[Stu S.]

Aluminum tanks: Hydro first, so you don't put any additional money into a product that fails later is production. Sanding is for paint adhesion and a good cleaning off of oxides. Set up a paint process that keeps the temperature fairly low, and nothing metallurgical will happen. Nothing metallurgical is going to happen to 6061 aluminum below about 400 degrees, anyway.

You can see from the production of tanks, that the cost to make a big one compared to a small one is minimal. All you get is a few extra inches of sheetmetal. What the videos did not show is that this is hot, smelly, noisy, and (certainly for steel) dirty work.

 

[Ed Palma]

Aluminum tanks: Hydro first, so you don't put any additional money into a product that fails later is production.

Man, why didn't that cross my mind sooner? Thanks!

 

[Scuba_Jenny]

Very cool. After the video, the related video choices include WaterKyles "I want to see a tank explode" video!

 

[JHamilton]

I have to say that I have been researching different materials to be used for lightweight oxygen tanks and this is exactly what I was looking for. Awesome!

 

[Stu S.]

Hey, divers. Most modern paints (we call them organic coatings) do not require curing temperatures close to affecting the metallurgy of a cylinder. Bake ovens speed up the process of a coating becoming solid. A lot of factories will use a system in the range of 150-200 degrees F.

Think about getting a car painted. If that "hot lights" room used to speed up the paint was at 350 or 400 degrees F, you would damage the rest of the vehicle. A coating requiring that kind of temperature would not be practical.

The concern over repainted tanks is mostly about hidden damage. If a cylinder had a gash in it, it could be made to look good with supplies from Pep Boys. Nobody wants that going on.

Those were great videos.

Stu.