acid polishing

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goldlb
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Joined: Thu Sep 30, 2004 5:53 pm
Location: Sacramento

acid polishing

Post by goldlb »

I am trying to find someone willing to teach me how to acid polish crystal with hydrofluric acid. I have the tanks and have tried to find papers written on technique but have been unsucessful. Can anyone direct me toward literature or people familiar with the technique. Thanks
Larry
Morganica
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Re: acid polishing

Post by Morganica »

Hey, Larry; I'm familiar with both. It's less about technique than it is about having ALL the right equipment to do it, not just the tanks (such as the right equipment to safely dispose of the spent solution without getting a visit from the EPA). Buying that right equipment usually makes it cost-prohibitive unless you're setting up as a polishing service. The last time I checked, a complete HF polishing setup and disposal service would run somewhere in the neighborhood of $40K. Where did you acquire the tanks and what kind do you have?

HF is an interesting beast. It's not incredibly strong as acids go, but it's got some unique properties. One of them is it penetrates your skin and pretty much destroys everything in its path until spent. And it's nastily toxic in very small doses. I had to use it in a chem lab internship I did one summer, and the safety measures we had to take to work safely with hot HF were pretty sobering. My boss made one mistake handling it, and I still have the scars.

If you're interested in having something acid-polished, or learning more about it, check with Crystal Traditions in Tiffin, Ohio. I understand there are a couple other services doing acid polishing in the US, but I don't know where they are. The other sources I'm familiar with are in the UK, China or the Czech Republic.

However, if you want to learn more about it, google "acid polishing glass" and you'll find several good papers.
Cynthia Morgan
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goldlb
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Location: Sacramento

Re: acid polishing

Post by goldlb »

Hi cynthia,
The tanks belong to david ruth
I don't know the type
We will set up the process in his studio in oakland or in sacramento. I have sent pieces to tiffin in the past but it is. Always a hassle
They do not do runs regularly and once shipped a piece back to me that was poprly packed and broken. They were unappologetic
I have found little on the internet and almost nothing om the online site for the corning museum
I do have motes that david got from marvin lipofsky but they are not very detailed
I would really like to watch the process before attpting it
Bert Weiss
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Re: acid polishing

Post by Bert Weiss »

HF is a bizarre material. You can successfully go outdoors and work with very simple plastic photo trays, respirator, goggles, apron, boots, gloves, water, litmus paper and baking soda. However HF sits on the danger scale, somewhere just below nuclear power. It can dissolve your eyeballs. Once on your skin, it goes straight inside, and all the water in the world won't stop it. You calcium bones will though. Sitting between skin and bones are nerves. Stories about HF mishaps abound. From pinholes in gloves to rapid death.

I was taught to acid etch flashed glasses by 2 glass artists from my parent's generation. It can be done. Having done some myself, my conclusion was to find another way to get the various jobs done. Life is too long to mess around with imminent disaster for the sake of art making...

Can you even get HF these days? Back in the 80's, I went over to the chemical company, bought a gallon, and took it home. I can't imagine what they do now about shipping it around.
Bert

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Morganica
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Re: acid polishing

Post by Morganica »

Yup, you can get HF. It's sold in a lot of places. Whether you can get the concentration you require is another question.

I've heard similar stories about Tiffin, so I don't blame you for wanting to find an alternative. They aren't the fastest in the world because they don't start up the line until they have a lot of work to be dipped, and they don't really return phone calls. When I've actually gotten to talk with a human there they've been very nice but not overly helpful in explaining the processes or requirements. If they weren't the only game in town I suspect they'd be a lot easier to deal with.

I've been told there are a couple of alternate services in the States, one in Colorado and another in New England somewhere. I have cousins who own an automobile factory that does all sorts of neat processes. I asked (begged, really) them to start up an acid polishing service as a complement--I'd be their best customer--and they considered it...right up until they looked into the regulations. They said it would be an EPA nightmare, their insurance would skyrocket, if indeed they could insure it. They flatly refused.

If you wanted to start up such a service you'll be well-stocked with customers, most likely...but whether it can dissolve your eyeballs or not, the real problem is handling and disposal. Correct management is (very) expensive, if you don't follow the laws you can get in a lot of trouble, and I suspect that's why there are so few commercial services doing it.

There are actually some fairly detailed explanations of the process at USPTO and in a couple of glass industry journals that I've seen. Here's one: http://www.google.com/patents/US4332649
I'd also send a note to the librarians at the Rakow in Corning and ask if they can find more detailed information. I still think it's a very risky proposition, but if you're determined, the more information, the better.
Cynthia Morgan
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Joe Pfeifer
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Re: acid polishing

Post by Joe Pfeifer »

If you want just a nice "frosting" kind of like on a frosted vodka bottle, use a (little bit safer) product: "Lerite"

http://www.seppic.com/industrial-specia ... Cn5fLLeg__

Like Richard Jolley, Tommie Rush use.
http://blog.al.com/entertainment-press- ... st_55.html
Peter Angel
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Re: acid polishing

Post by Peter Angel »

There are companies that provide acid etching and acid polishing for a small fee.
Peter Angel
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Morganica
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Re: acid polishing

Post by Morganica »

Believe it or not, Peter, most of the ones I know are in your neck of the woods, or in Asia. It's amazingly scarce in the US.
Cynthia Morgan
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http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)
jim simmons
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Re: acid polishing

Post by jim simmons »

Also, for some more information, get the MSDS for HF. (Material safety data sheet>) do a search for it.
That should scare you also.
Jim
KaCe
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Re: acid polishing

Post by KaCe »

I used HF on flash glass to create some very nice images. The acid ate away the color and left nice clear glass behind. I, too, used a college lab with ventilators and emergency equipment incase of accidents. The instructor told us how he learned from a guy who was very casual around it and did not take precautions. The lining of his nose was gone from breathing it without protection and his hands were a mess of scar tissue. I gave some thought to doing more with it, but passed when I gave it further thought. Here when you purchase it you must transport it outside of the passenger compartment of your vehicle (pickup). And then like Cynthia said EPA wants their safeguards followed. Good luck. I hope you post again to say how it is going; or not going.
Greg Rawls
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Re: acid polishing

Post by Greg Rawls »

Totally agree with what everyone has said about hydrofluoric acid. Can not say enough not to use this stuff. There is no room for error on the personal protection equipment.

Greg, Certified Industrial Hygienist
Greg
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