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Ted Coffey
08-06-2005, 10:01 AM
Many of you know this I am sure but,
for the others that have the occasion to weld galvanize steel, Muratic acid is a easy way to strip the glavanize. For example, to clean the galvanize from the end of a piece of pipe set end of pipe in a plastic bucket with Muratic acid(available in local hardware stores). The solution can be full strength or diluted but don't add water to the acid(It will spit at you) instead add the acid to the water. After a few minutes of bubbling the end of the pipe will be stripped. Make up a bucket of water and bleach and dip the pipe to neutralize the acid on the pipe. The acid can be reused many times and refortified by adding fresh acid. I normally use the acid full strength unless I am cleaning a large piece and I have more time than money.

ibewgypsie
08-06-2005, 10:07 AM
The smoke off OLD galvanize while welding will give you such a headache you pray for relief.

It also craps up a good weld.

You grind it till it turns blue, the galvanize penetrates the metal for a certain depth.

Yeah, I like the ideal of chemical stripping. Much better than inhaling that grind dust.

David

Ted Coffey
08-06-2005, 10:18 AM
I used to grind it off but with some shapes like pipe you can't very easily remove the inside galvanize by grinding. I used to get flu like symptoms from the grind dust and from welding. It is nasty stuff.

lynnl
08-06-2005, 12:13 PM
Hey Thanks to you both!!!

You just solved a problem for me, without my even having to ask any questions.

I'm wanting to weld up a light tool stand of 1,5" galv EMT. And I didn't look forward to trying to grind off that galvanizing.

[This message has been edited by lynnl (edited 08-06-2005).]

crossthreaded
08-06-2005, 03:47 PM
Whats to worry. An acetyline torch turns most galanize to vapor pretty quick. Human lungs are very efficient at soaking up that vapor. You didn't want to get it into the environment & poison squirels & bunny rabits did you?

BillH
08-06-2005, 03:50 PM
Hmm, Thanks, I can use that same system for cleaning up silver soldered parts for my locomotive.

ibewgypsie
08-06-2005, 06:20 PM
Lynn:

EMT is brittle. Probably made out of trash steel. I have made quite a few things from it including a out-building for a harley. You can get it for the removal. Usually I got paid both ways, to remove it and haul it off.

I used to be able to stick weld it. I can't anymore. I guess I fell into the trap of burning hot and fast.

Thinwall square tubing, 14/18 ga is cheap. I got a pile from a auction 2x2 and have used it for everything. TWO welded back to back will not hold the pressure from a 4" air cylinder on 100psi thou.. I got mad at myself for trying that. I crushed it.

I do have a 1000lb welding table sitting on two legs made from it.

David

BillB
08-06-2005, 07:05 PM
A well known NC blacksmith, Jim "Paw-Paw" Wilson, died last May from the after effects of inhaling zinc fumes.

If you're going to be near such fumes, you should wear a HEPA (N99) mask. I do.

Ted, great idea.

BillB

wierdscience
08-06-2005, 09:57 PM
I aviod welding galvanized anything,it's very bad for your health,zinc poisoning is not pleasant.Then there is the issue of strength,you can figure on the yield being 1/2 of black iron A36.

winchman
08-07-2005, 12:16 AM
Here's something about a new process for removing (and recycling) zinc from scrap steel. Don't know how hard it would be to adapt to the small job, though.
http://www.transportation.anl.gov/research/recycling/zinc.html

Roger

Ian B
08-07-2005, 06:08 AM
Roger,

The process sounds like the reverse of electroplating with zinc; maybe someone who's been doing zinc electroplating in the home workshop could switch the battery cables around and let us know what happens...

Ian

Tinker2
08-07-2005, 12:36 PM
I hear that milk is a anidote for effects of inhaling zinc fumes??

Anyone know??

wierdscience
08-07-2005, 12:55 PM
<font face="Verdana, Arial" size="2">Originally posted by Tinker2:
I hear that milk is a anidote for effects of inhaling zinc fumes??

Anyone know??</font>

Thats what I here too,I think it's the clacium that does it,or maybe the dehydrating effects of dairy.

Best not to breathe it in the first place.

madman
08-08-2005, 07:42 AM
Yeah milk is the antidote. Or dont weld galvanized is better yet.

dsergison
08-08-2005, 08:48 AM
surprised Forrest hasn't gone off of the galvanized welding evils yet.

It makes your lungs fill with fluid. Milk may get the taste out if youre mouth but it won't save you from dying a horrible drowning death if you get to much.