Liquid Wrench

Jim Smith wrote:

Tom Sherman writes:


Størker Moe wrote:


Yup, ammonia is a base. For the more extreme cases, a solution of
caustic (AKA sodium hydroxide) literally removes the seatpost. The
base dissolves aluminum forming sodium aluminum hydroxide and
hydrogen gas. Takes some time with thick-walled seatposts, but it
works. I tried it once after using up two hacksaw blades and still
not having gone through the post.
Don't try this at home, kids, and read the MSDS.

Is sodium hydroxide any worse than potassium hydroxide? I have had
skin contact with potassium hydroxide many times and as long as it was
washed off right away, it was not big deal.


They are both about the same, but don't let your experience with KOH
fool you, these are not exactly benign compounds. They are not
"poisonous" per se, but strong solutions will happily disolve your
flesh. Brief skin contact is no big deal, but get some in your eye or
swallow some and you are likely to have problems. (There are lots of
folks running around who can't eat anymore and have to collect their
spit in a cup because they tried to kill themselves drinking drain
cleaner.) Just use common sense and follow standard safety
precautions like wearing goggles and always adding the crystals to the
water and not the other way around.

Actually, I used to work in the R&D department of Rayovac as a lab
technician, and there were times when I was too lazy to put rubber
gloves on if I was just briefly doing something involving KOH (which we
made up in 50 gallon batches at 45% concentration), or gelled anode
(which has a pH of about 12.5).

--
Tom Sherman - Earth

Tom Sherman writes:

Jim Smith wrote:

Tom Sherman writes:

Størker Moe wrote:


Yup, ammonia is a base. For the more extreme cases, a solution of
caustic (AKA sodium hydroxide) literally removes the seatpost. The
base dissolves aluminum forming sodium aluminum hydroxide and
hydrogen gas. Takes some time with thick-walled seatposts, but it
works. I tried it once after using up two hacksaw blades and still
not having gone through the post.
Don't try this at home, kids, and read the MSDS.

Is sodium hydroxide any worse than potassium hydroxide? I have had
skin contact with potassium hydroxide many times and as long as it was
washed off right away, it was not big deal.
They are both about the same, but don't let your experience with KOH
fool you, these are not exactly benign compounds. They are not
"poisonous" per se, but strong solutions will happily disolve your
flesh. Brief skin contact is no big deal, but get some in your eye or
swallow some and you are likely to have problems. (There are lots of
folks running around who can't eat anymore and have to collect their
spit in a cup because they tried to kill themselves drinking drain
cleaner.) Just use common sense and follow standard safety
precautions like wearing goggles and always adding the crystals to the
water and not the other way around.

Actually, I used to work in the R&D department of Rayovac as a lab
technician, and there were times when I was too lazy to put rubber
gloves on if I was just briefly doing something involving KOH (which
we made up in 50 gallon batches at 45% concentration), or gelled anode
(which has a pH of about 12.5).

Sounds reasonable, but I wouldn't want to get any in my eyes.

Tom Sherman writes:

Actually, I used to work in the R&D department of Rayovac as a lab
technician, and there were times when I was too lazy to put rubber
gloves on if I was just briefly doing something involving KOH (which
we made up in 50 gallon batches at 45% concentration), or gelled anode
(which has a pH of about 12.5).

heh. I never thought about that before. I guess that is why they are
called "alkaline" batteries.

Størker Moe wrote:

Don't try this at home, kids, and read the MSDS.

Yup, be careful. Fortunately I was. When I was 12 years old back in about
1966 we used NaOH, water and Al in glass Coca-Cola bottles to inflate
baloons, attach a note with our address, and hope that we'd get one back.
Several of us did - me too. I still have the note in "my archives". We were
ALL lucky that we never got burned by the NaOH solution.