Weld black pipe or galvanized

[john_bud]

Miracle Water Stan Remover (hydrofluoric acid ... another bad hombre) ... it etches so good, paint sticks like a bad girl on a rich dude.

Homebrew2,

I am going to call you on this one. I think you may have mis-read the label. I know what HF does, it penetrates the skin painlessly and then hours later dissolves your bones with excruciating agony. I know of no home use for HF. Industrial uses are for glass etching and anisotropic etching of silicon. As a pre-welding treatment...never heard of it.

If I am wrong, please point me to the correct info. I did a quick search on the name you gave and found no such product. But, I am not the best searcher.

jb

 

[Deerlope]

I woulldn't use pipe at all, hollow square tube is better.

 

[AlanB]

Jeez, attached is a pic of an old 2" galv el welded to some old, rusty, angle (15 minutes ago). 90A, 6010 (AC), 10 beers and no patience for "you have to follow 'these' rules to get anything done!
Cheers

HomeBrew are you like some of the painters I know by chance? In other words, could you do the same weld without the 10 beers? (just kidding you if it was not obvious)

To the original poster, if durability and weather resistance was critical, I would go with the galvanized, I would grind the galv to clean most of it off in my weld area, it will make it more difficult to see the puddle, and judging from the OP that will be important. I would reccomend the fan, etc. etc (unless you are doing MIG) as Homebrew said, short version, NONE of these welding fumes are good for you, and wether it is long term health effects, or just being sick to your stomach and feeling like you are about to puke for a couple of days, I would avoid breathing the galv fumes.

If I was buying new materials, and exposure was not a problem, I would go with price and less grinding and go black pipe.

If this thing has to be painted to look good, I would definetely go black, all the best galv primers, wash primers, acid wash etc. only make paint kinda stick to galv. Far easier to get a decent paint job on Black.

Good luck.

 

[HomeBrew2]

Yeh, I see what you mean. I can't find it in a search either. I admit, this bottle could be 10 years old. I bought it to remove, what had become, a solid sheet of calcium on my sliding glass door (sprinkler spray) ... didn't actually get around to that job till last year
Attached is a pic of the label, and one of fine print. There is enough resolution to read it all ... hopefully it gets posted as such.
I'm sure other stuff works. This is just what I had on hand and it really gnaws the galv well.
At what concentration and how much exposure causes the gruesome results you relate?

Homebrew2,

I am going to call you on this one. I think you may have mis-read the label. I know what HF does, it penetrates the skin painlessly and then hours later dissolves your bones with excruciating agony. I know of no home use for HF. Industrial uses are for glass etching and anisotropic etching of silicon. As a pre-welding treatment...never heard of it.

If I am wrong, please point me to the correct info. I did a quick search on the name you gave and found no such product. But, I am not the best searcher.

jb

 

[Ronbo]

My neighbor is a chemist at one of the local plants. He is also a hobby welder. Uses galv all the time. First drik a glass of milk. Keeps the absorption in the intestines down. Second soak the end that you are welding in vanquish toilet bowl cleaner. Acid removes the galvanized. If cleaning carborator parts with vanquish, don't leave avoer night, ask my brother in law. Third use an autodarkening hood when weldin, personal preference. Fourth spray paint it when hot, i like the sizzle and makes a harder finish.

Ron

 

[john_bud]

Yeh, I see what you mean. I can't find it in a search either. I admit, this bottle could be 10 years old. I bought it to remove, what had become, a solid sheet of calcium on my sliding glass door (sprinkler spray) ... didn't actually get around to that job till last year
Attached is a pic of the label, and one of fine print. There is enough resolution to read it all ... hopefully it gets posted as such.
I'm sure other stuff works. This is just what I had on hand and it really gnaws the galv well.
At what concentration and how much exposure causes the gruesome results you relate?

Looks like you can read! And were correct. I don't know the answer to your exposure Q, but From Wiki on hydrofluoric acid;

Safety


Symptoms of skin exposure to dilute HF are not felt immediately, but exposure of less than 10% of the body to it can be fatal, even with immediate medical treatment. Highly concentrated solutions may lead to acute hypocalcemia, followed by cardiac arrest and death, and will usually be fatal in as little as 2% body exposure (about the size of the sole of the foot). This substance is extremely toxic and has the capacity to kill upon exposure rather than simply damage skin and eyes. It should be handled with extreme care, beyond that given to hydrochloric, sulfuric, or other mineral acids.

Due to low dissociation constant, HF can penetrate tissues quickly like a small non-polar particle. Hydrofluoric acid which comes into direct contact with the fingers can severely damage or destroy the tissue underneath the nail without causing any damage to the nail itself. It is this ability to cause little harm to outer tissues but considerable harm to inner tissues which can produce dangerous delays in treatment of hydrofluoric acid exposure. Once the pain starts, it is out of proportion to the burns produced. Patients often describe the feeling as if they have struck their fingers with a hammer. HF that penetrates under the skin causes later development of painful ulcers, which heal slowly.

------

The highest concentration of HF in air that can be tolerated by a human for 1 minute is 100 mg/m3. This causes a definite sensation of pain on the skin, a definite sour taste, and some degree of eye and respiratory irritation. If the air contains 50 mg/m3, the sour taste is apparent and there is irritation of the eyes and nose, but no pain is sensed on the skin. The concentration of 26 mg/m3 can be tolerated for several minutes, but the sour taste becomes evident after a short time, and there is mild pain in the nose and eyes. The American Conference of Governmental Industrial Hygienists has adopted 2 mg/m3 as the threshold limit for hydrogen fluoride. This comes to about 3 ppm (parts per million). Inhalational exposure to concentrated HF for as little as 5 minutes is usually fatal, producing death within 2-10 hours.





Personally, I would trash that stuff ASAP. There are other safer chemicals that will do the same thing. It is probably a very dilute solution, but not stuff to be used lightly.

jb

 

[Jimbrown]

Jeeze guys I never thought such a simple question would cause such responses. Next time I will ask something less contoversal like maybe anyone got a virgin daughter for sale. My first choice was square tubing but all I find is 1 in and 1 1/2 which is too big or small. I guess I will use black unless I find some 1 1/4 square. Thanks a lot for the help.

 

[HomeBrew2]

Looks like you can read! ... jb

Just barely, I try my best.

... Personally, I would trash that stuff ASAP. ... jb

Thanks for the tip, I'll store it with my stockpile of carbon tet and DDT and use them all judiciously.

 

[cp1969]

I woulldn't use pipe at all, hollow square tube is better.

Yeah, but have you priced any lately? Metal prices have gone through the roof.

 

[HomeBrew2]

... anyone got a virgin daughter for sale. ...

Maybe give a man a little lead time in the future ... just sold her, and got top dollar