Deep acid etch face up

[Jerry Berg]

After viewing Dave's "23" post I have a question or two.

When doing a face up deep acid etch what would be the procedure?

Is this correct:
1: Clean and mask with vinyl including sides and face
2: Level glass perfectly face up in tub 1/2" off the bottom of tub
3: Mix acid same as Dave's percentages
4: Add the acid mix so acid rises to slightly cover edges
5: Time 45 minutes, remove and wash

Also, what prevents acid from getting under the mask when chipping and then etching. Careful masking?

Thanks,
Jerry

[Larry White]

Hey AE's-

Sounds like you've combined face-up and face-down there in your list.
When doing a face-up etch, there would be no need to space the glass off the bottom of the vat, but you would if you were doing the face-down method. Face-up and face-down will yield two different looks. Might be a bit hard to aquire that 76% strength acid, but not impossible. I've only seen the 48-52% strength around these parts. So the dilution ratio would need altering if using the weaker acid. You would do your step 4, for a face-down etch. When doing face-up, the glass would be submerged. Varying times will yield different effects. When doing a face-down etch, you need to ensure there are no air bubbles trapped under the glass. Also, ensure you have a safe method of returning the acid to it's container.

AND...
CAUTION: READ ALL SAFETY LITERATURE AND INSTRUCTIONS BEFORE USING HYDROFLOURIC ACID OR ANY OTHER DANGEROUS MATERIALS THAT MIGHT BE MENTIONED ON THE BULLETIN BOARD! PROPER USE, HANDLING AND DISPOSAL OF HAZARDOUS MATERIALS IS THE SOLE RESPONSIBILITY OF THE END USER ONLY!!

[Jerry Berg]

You're right Larry, I suppose I should have separated the two questions. I'm aware of these things.

Submerged is the answer I was looking for, Thanks Larry. I'll do a test piece for etching & chipping.

[Patrick Mackle]

Hi Jerry,
I used to buy 70% in gallon bottles. You should know that in 70% it is really strong. Too strong in fact for the factory bottle its packed in.
I left a new unopened bottle resting in its opened card board box on the floor in my garage while I took off to Denver to take wheel engraving lessons.
In less than the week I was gone, the fumes bleeding through the bottle crossed the garage floor and turned the lower 4" of the sheets of cobalt blue glass to a
loose powdery white residue. Within a few months the heavy guage nylon acid bottle had grown hard blisters all around the upper half.

One time I used a wooden stick to stir a diluted but still strong mixture of HF and water. I heard an odd sizzling sound and looked down to see greenish sap being driven out of the top end of the wooden stir stick. It appears that the penetration of the fluoride gas suspended in the liquid HF had soaked into the wood. It does the same to your skin as skin is highly capable of that absorption.
I heard tales that old glass embossing shops made a practice of storing strong HF in wooden boxes stuffed with newspaper to keep the fumes. I found out first hand with that ruined cobalt blue sheet glass.
Back in 1983 when I first flew to the UK to visit Nero Glass and Clark Eaton, the works manager at Clark Eaton asked why I was buying 70% when after all, embossing acid is used at a much lesser strength. He would not handle 70%, too dangerous in his opinion. Strong solutions actually "burn" the glass and leave an ugly texture.
There are a lot of finer points about using HF. Too much to list on this reply without rambling.
Let's talk sometime.
Pat

[erik winkler]

I want to ad some extra information on Pat's post.
I collected my Mica-HF mixture in a plastic container with a press down snap lid (I really do know how the English name for this).
Because HF vapourises well under room temperature it was pressurising in my container which was locked up in a special metall safety cabinet/closet.
When I wanted to use the mixture again after two weeks I noticed that the lid come of a little and when I removed the mixture from the glas after the necessary period nothing happened to the glass at all! All the HF-acid was gone/vapourised out of the mixture and plastic container in the open air inside our bussiness!! Some minutes later I discovered that a lot of my glass jars I keep in the same metal closet were attacked due to the acid fumes. They had an white sandblasting/whiteetching lookto them. Since that moment I not only collect them in a plastic that can handle the HF-acid, but also is able to contain fumes under a little pressure.

Furture more I want to at that because HF vapourises wel under room temperature a 70-75 concentration will blow out white fumes of pure HF-acid!!!
Do not work inside!!!!

One other thing, a lot of scary stories go around about this way to dangerous stuff, I do not recall anybody posting some photo's of what could happen.
I collected some photo's (not for children and only for someone who has a strong stumach!) and because I want to keep this a clean site I will only post a link to my Photobucket slideshow.

http://s288.photobucket.com/albums/ll20 ... =slideshow
The photo's only show surface damage, but the mostdangerous thing is that it attacks the bones and calcium in your blood, so preventing oxigene transportation and is therefore lethal.

Hope this helps someone...
Erik

[Patrick Mackle]

Of those photos that Erik found, I would like to point out that accidental splash contact most likely caused the face and thigh traumas.
The MORE INSIDIOUS BURNS are the concentrated deep tissue burn areas on hands and fingers were the user had placed blind faith in the belief that the acid resistant gloves they were wearing made them 100% safe. A tiny pin hole will allow the acid to enter the glove and the wearer will be UNABLE TO DETECT the defect due to his own natural perspiration build up in the nitrile glove. These burns are often DEEPER and MORE SEVERE because of the often long period of time that the hand is in the glove.
Hf does not cause immediate burning heat and pain like other acids! It's more like a sun burn. You don't know that you've had too much until the damage is already deep in the skin tissue and then eventually the bone.
Pat