Pickling Paste on stainless steel: WHITE HAZE WON'T COME OFF

while I'm on a posting roll...
I've used pickling paste on 316L for the last few of my sculptures,
but I've had a disturbing thing happening... While it brightens the
stainless (almost a blue tint) and removes all the little surface rust
spots, it also leaves a coating... almost of a 'smudged' look..
I leave the past on for about 15 to 20 minutes and agitate it with a
nylon brush before rinsing and rubbing (with my rubber gloves on) it
off.
What Am I doing wrong?
Thanks,
James, Seattle (port orchard, Washington, USA, Earth
Reply to
RainLover
Loading thread data ...
Sorry I cant give an answer to your question about the smudging, but please be super careful with that pickling paste. It may contain hydro-fluoric acid which is shocking stuff if you get it on your skin. Look up the material saftey notes on it. Please be careful with it.
Sorry to sound like a worry wart but I'd hate someone to loose fingers simply because they didn't know how bad this stuff can be.
Dean.
Reply to
Dean
Fingers hell... According to what I've heard/read over the years, spilling hydroflouric acid on your fingertips equals "We're going to need to take your arm off at the shoulder - Just to be sure."
Reply to
Don Bruder
It's even worse than you think. If it gets inside of you it will literally attack you from the inside out. You don't even have to get in your mouth or breath it. It will absorb through the skin. I knew a guy years ago working in a plant that used hydrofluoric acid for electropolishing metals. He accidentally tripped and managed to step into an open shallow vat of it. Got only up to his ankles as I recall. They didn't stop the absorption fast enough and it got inside of him. Literally corroded him from the inside out. Attacked his bones in particular. Took him a few days to die. What a bloody horrible way to go. Made me sick to my stomach when I heard what had happened to him. If this pickling material does contain HF then be VERY careful. There is a special cream you can get if you are working with HF. I think it's calcium gluconate. If you get any HF on you get this cream on the affected area ASAP.
Reply to
C.A. Decker
Nothing. The acid is just etching the surface (that's what pickling is supposed to do). If you want it shiny, you'll have to polish it after pickling.
Gary
Reply to
Gary Coffman
HI Dean...Thanks for the warning... I know how nasty Hydo-fluoric acid is and it DOES contain it, along with some other nasties. I wear a full organic facemask/filter, long sleeves, chemical gloves and have a hose right next to me in case of accident.
It's the "worry warts" that have all their eyes and ears and skin when they retire.....
James, Seattle
Reply to
RainLover
Hm... that's too bad. I put a 'texture' into the stainless steel so any other machining would destroy it... any idea how I could pickle it AND have it be shiny afterwards?
James, Seattle
Reply to
RainLover
electropolishing seems to be the only way, but i think it will remove about 40 microns of surface material
Reply to
adchin
Would some type of blast media satisfy your needs?
Bob S.
Reply to
Robert Scibienski
Guys - Be very careful with any chemical and/or welding or brazing alloys or products you use. WHMIS regulations that came out in the early 1990's worldwide made it law that all such products should have any hazards listed clearly on the product itself on what they call a WHMIS label, and that a MATERIAL SAFETY DATA SHEET be available from wherever you purchase the product. This gives the name of the manufacturer, Distributor, all of the ingredients, their percentages and all hazards. If your product doesn't come with that or you can't access it - drop the product. Any reputable manufacturer will provide all safety precautions on their products and/or hazards. Sincerely Yours, Judy M
Reply to
Must Sell
Hi James. Besides all the warnings about the hazards of Hydrofluoric Acid, I thought I might help you a little.
The haze is usually where you have etched the metal. If the haze refuses to come off with a mechanical process, like a wire wheel on a grinder, then I wonder if you are making the mistake of puting it on when the metal is still hot . Always wait until he metal is cold to the touch.
I went to Citric Acid Passivation 2 years ago and have never regretted it. No toxic chemicals and it works very fast.
If you are intertested you can come by my shop in Renton and I can demo it for you, or maybe you can lure me out to your shop finally.
I can usually be bribed with food and gas money.
The stuff I use is type 9002 Citrisurf
You can check it out here.
formatting link
Reply to
Ernie Leimkuhler
Hi Ernie,
I've been wanting to get out to your place for over a year now... I really need to. I looked at teh Citrisurf web site and it looks like the stainless needs to be put into a hot bath of the product, is that the case? it would be difficult for me to make a tank that would accomodate my sculpture since every one is a different (and large) size.
How do you do it? I like the brush application of the Hydrofluoric Paste, but I definately don't like the acid itself!
Thanks, James, Port Orchard
Reply to
RainLover
I use Electro-passivation. I apply the citrisurf with a wand that is connected to one side of a 36 volt DC power source. The other side is grounded to the piece. The paste carries the electrical current which catalizes the citric acid. It is extremely fast and very non-toxic.
Reply to
Ernie Leimkuhler
On Sun, 05 Sep 2004 22:57:25 GMT, Ernie Leimkuhler calmly ranted:
Does it leave a pristine surface, no "brush marks"?
========================================================== CAUTION: Do NOT look directly into laser with remaining eyeball! ==========================================================
formatting link
Comprehensive Website Design
Reply to
Larry Jaques
[pickling]
Can you describe the wand? Is it just a metal rod or does it have a conductive (carbon?) brush? (I mean brush in the paint, rather than DC motor, sense)
Tim
Reply to
Tim Auton
No brush marks. If you leave the wand in one spot too long you can etch the surface.
It works very well for removing oxidation colors from brushed stainless without harming the brushed surface.
Reply to
Ernie Leimkuhler

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.