[TheForge] Spring steel (and other) breaking in mild acid

[peter fels]

That was my first thought, but it was very mild acid and did the same thing to bering races.
I've cut and exposed hundreds, if not thousands of coil spring and garage door spring loops to heavy salt corrosion,
and seen very , very few failures. A fair # of those were actively flexing in wind powered kinetic pieces.
Salt water corrosion selectively seeks out small fatigue cracks.
Clyde's results were very odd. He is an excellent observer.

On Aug 25, 2011, at 7:36 PM, Kim George wrote:

> It could be the fracturing of stress cracks. The acid eats the surface
> allowing the cracks to separate.Ever try forging an old coil spring of
> a car? same thing.
> 
> On 8/25/11, peter fels <artgawk at thegrid.net> wrote:
>> That's a complete mystery to me!
>> Be very interested to hear what our experts say Clyde.
>> 
>> 
>> On Aug 25, 2011, at 5:48 PM, Clyde Wynia wrote:
>> 
>>> 
>>> I make part of a piece of sculpture that serves as a back for a cat. I
>>> take
>>> a piece of 3/8" rod about 18" long and bend it into not quite a semi
>>> circle.
>>> I then take a piece of garage door spring about 2" diameter and slip it
>>> over
>>> the U shaped rod. This is just a very mild bend around the rod. I do not
>>> weld the spring in any place, only the rod is welded to the legs.
>>> 
>>> As I do with hundreds of other pieces, I put the piece, not hot, into a
>>> mild, 10 to 1, bath of water and muriatic acid to remove the mill scale,
>>> rust etc. The solution by this time of year is very weak. However, when I
>>> remove the piece the spring is broken into 1 to 4 pieces.
>>> 
>>> This also happens with bearing races, 5" to 7" diameter that have been put
>>> into the acid. The cross crack does not occur near a weld and is not put
>>> in
>>> the solution hot.
>>> 
>>> So what is happening to cause these breaks in this very mild acid
>>> solution?
>>> 
>>> Clyde Wynia
>>> 
>>> ______________________________________________________________
>>> TheForge mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:TheForge at mailman.qth.net
>>> 
>>> TheForge mail list group photo site is
>>> http://www.photoworks.com
>>> Login: blacksmithblacksmith at hotmail.com
>>> Password: anvil
>>> 
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>> 
>> ______________________________________________________________
>> TheForge mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:TheForge at mailman.qth.net
>> 
>> TheForge mail list group photo site is
>> http://www.photoworks.com
>> Login: blacksmithblacksmith at hotmail.com
>> Password: anvil
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> 
> 
> 
> -- 
> Kim George
> 
> "Why for you try to bury me in cold,cold ground?"
>     Taz
> ______________________________________________________________
> TheForge mailing list
> Home: http://mailman.qth.net/mailman/listinfo/theforge
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:TheForge at mailman.qth.net
> 
> TheForge mail list group photo site is
> http://www.photoworks.com
> Login: blacksmithblacksmith at hotmail.com
> Password: anvil
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html