Fuel Tank Water Storage

[Fred61]

What do these PH boosters do to the copper coil or any solder connection one might have in the tank? When I removed the discarded steel tank and transferred the coil to the stainless tank, the copper seemed to have a rough surface. I assumed the chemical I added had something to do with it.
Sodium hydroxide is powerful stuff. I used to etch glass with it when I was building disk drive recording heads.

 

[maple1]

I don't know but would like to find out fairly soon, so all input welcome. I'm hoping to have my storage tanks in place & start filling them in the next week or so (I'll take a while - dug well plus really dry summer) - although I guess if I was going to add treatment I could do it anytime. I have some test strips around here somewhere - got them & never used them. Not sure how good they work, but when I had my water tested a couple years ago the fellow said it was 'slightly acidic' - kind of a vague term. I wasn't planning on doing any treatment (pressurized system but with non-diapraghm expansion), but these threads get me thinking...

 

[Bob Rohr]

I don't know but would like to find out fairly soon, so all input welcome. I'm hoping to have my storage tanks in place & start filling them in the next week or so (I'll take a while - dug well plus really dry summer) - although I guess if I was going to add treatment I could do it anytime. I have some test strips around here somewhere - got them & never used them. Not sure how good they work, but when I had my water tested a couple years ago the fellow said it was 'slightly acidic' - kind of a vague term. I wasn't planning on doing any treatment (pressurized system but with non-diapraghm expansion), but these threads get me thinking...

Maybe contact some of the hydronic conditioner manufacturers for some help, or visit some websites. It seem that hydronic chemicals have multiple components, not a single chemical solution . I know the ph of hydronic or solar glycols have a ph of 10- 11.5 ph due to the blend of additives. I don't think you would just buffer plain tap water to that ph without considering what happens to the multiple of metals in the system like steel, brass, copper, possibly aluminum.

As I recall the Rhomar Water hydronic conditioners have about 27 different components, as the price reflects But when you look at protecting multi metals over a wide temperature range it takes a "cocktail" of chemicals.

The conditioner package needs to buffer ph, scavange O2, lock up hardness, provide a thin protective film, like rust, etc. If you have an open system the O2 scavange chemical will need to be boosted from time to time. That depends a lot on temperature of the fluid also.

In a closed system the treatment is not as critical, but still a wise investment. Many closed loop hydronic systems are filled with tap water, on day one and last for decades like that. Even the paper thin steel expansion tanks live happily in closed loop, tap water filled systems. The O2 in the initial fill water actually oxidizes on the steel or cast components and helps provide a protective barrier. Just like rust does or anodized aluminum.

hr

 

[heaterman]

Sorry...
If it makes you feel any better, I'm not really professional, just a very experienced amateur.

And he slept at a Holiday Inn Express last night

 

[infinitymike]

I have a dumb question. On a closed pressurized system how do I add any treatment?

 

[infinitymike]

I'm not saying I'm a pro at everything or never wrong, very far from, but I think all can understand my frustration?

Yes you can weld with water on the other side, or heck in water even, but it doesn't weld decent WITHOUT having specific equipment that can crank the heat and shield the weld properly... none of that the average "hobbyist" weldor will have.

So without typing way too much, this is very much correct: "It doesn't weld good with water around it like that. Sure in a pinch you do what you have do (water main is leaking or something), but the water pulls the heat from the weld."

Although I only posed the question about water and welding. II want to clarify that I asked if you could fill the tank to PUSH any fumes out and then LOWER the water level below the fitting then do the welding. Not having the water up against the fitting but just below it.

 

[Mark Holden]

It depends... for a tank that was used for heavy oil like diesel, a couple of inches from the weld is fine. For a tank that was used with something volatile like gasoline, I like the water very close to the weld, nearly touching. Even then, little pops of combustion occurred while I was working. That was open flame brazing on an automobile tank. I was working as a mechanic at the time, so that was "professional" work.
I was just pointing out that it is possible to weld in the presence of water, within limits, and that I've actually done it. It's a little difficult, but not extreme. I used between 10% and 30% extra amps.
It's not just a matter of pushing the fumes out, there is always residue left in the tank that creates new fumes.
I've been told it's the high humidity in the water filled tank that prevents explosion in the gas above the water. All I know for sure is that I've done it that way [water an inch below the weld] several times without mishap.

My dad told me of a gasoline tank left out in a field for 12 years. One day, someone needed exactly that tank, it just had a small hole that needed welding. So they brought it into the shop.
The second the torch touched it, it blew up, opening out into a flat sheet of steel that fell to the floor after hitting the ceiling.
I really don't want to be around when the fumes blow in a big heavy tank; I've heard some stories and that's close enough.
Lots of welders refuse to even let fuel tanks into their shops, never mind weld on them. In the US, there are insurance issues.
So what I wanted to say was, make sure you have someone willing to work on it before you buy an old fuel tank.

 

[Fred61]

However, there's a junkyard not far from here that I frequent that has a crew continuously in the yard slicing and dicing steel for delivery to their market. One day when I was over there the crew was into a mountain of propane tanks. I saw one worker turning a horizontal 250 gallon tank into about 20 pieces. I approached him and asked what he did to remove any remaining gas and he said, "Well the valve has been open for nearly a month".
Can you believe that this guy is still on this earth!

 

[Mark Holden]

Propane tanks, surprisingly, aren't as dangerous. Once the gas is gone, all that's left is a pool of powerfully scented oily water.
Before cutting a propane tank, I take the valve off, fill it with water, and let it stand for a few days. Then empty and cut.
I haven't worked on one of those big ones yet. I've made some things out of little ones.

 

[maple1]

My tanks were still stinking pretty strongly when I brought them home. After sitting in my yard for a couple weeks with the top & bottom holes unplugged (no idea how long they were at the scrap yard open - but it was a while), I decided I should try to make sure they were relatively safe for the welder. Thought I'd throw some fun in the mix & stick a piece of burning paper up to the bottom hole (with a very long stick) to see what would happen. The paper burned out. Kind of disappointing. After that I stuck the pressure washer inside to be extra sure - turned out the welder wasn't worried much anyway, just said propane tanks aren't as bad as people think.

 

[Mark Holden]

I was trying to figure out what I could use as a heat store tank; so I imagined the perfect object, and Eureka! I had the idea.
I'm a genius, I thought to myself, a scrap propane tank is exactly what I need.

Then I found this forum and found out you guys have all stolen my idea before I even thought of it.
How irritating...