Skirting for ACID

[Andrey Kolmakov]

I found on the Internet a recipe of white acid, and try to work with it. And I can not think of how to do skirting for ACID. From what you make it ???? And one more question. How long should the etched glass ???? How many minute ???

[Andrey Kolmakov]

I am protected from the acid

[Larry White]

Use plastic vat slightly larger than glass.
Protect face of glass with coat of asphaltum (or suitable vinyl).
Place glass in vat.
Fill vat with acid 1/2 inch deep over the glass.
Do not pour acid onto glass, pour along side into the vat.
Allow to etch for 90 minutes.
Remove glass from acid and rinse.
Pour acid back into container.
Rinse vat and fill with the same amount of water (as there was acid).
Soak etched glass for 60 minutes.
Scrub with soft bristle brush until smooth.

Times can vary depending on strength of acid.

Be very careful with acid handling and storage.

Hope that helps.

[Mike Jackson]

https://fscimage.fishersci.com/msds/11171.htm

Here's the Materials Data Safety Sheet for Hydroflouric Acid. When people start talking about Acid, it is always a good idea to include notices of the danger of working with the materials.

Mike Jackson

[Doug Bernhardt]

Here's a photo from Nero Glass works in London England. They were using talo (sp?) for the dams around the glass as scene in the attached photo. Was there with Dave Smith a few years ago.

[Ingrid Mager]

Sorry, I'm going to hijack the thread a bit, but it's all about HFA, so I figure this is as good a place to put this as any place else:

I am in preparation for doing HFA work. . .rendered my own tallow. . . .have all personal safety devices in place. . . . have studied,studied, studied, etc. . etc.. >>>EXCEPT<<<<

My living quarters are directly above the shop space and the only entrance is through the shop itself. (See attached schematic) I am concerned about venting in such a way that there is no possibility of toxic fumes creeping to the upper level where I live with my three cats who will be up there while I do the acid below. . . .and where I will need to go myself in between procedures, unless I sit and watch the acid do its thing.

An artistic HFA pro I talked to told me that they always work inside in a vented space. Naturally, I originally planned on working just in front of one of the overhead doors, with a fan between the work and the door to draw fumes out. But now I am beginning to wonder if it might be better for me to work outside. This place is remote. . . has a very low wind factor, and the chance of other people or animals showing up is generally not likely. It's usually around 20º outside this time of year, but HFA's freezing point is around -37º, so that should not be an issue.

Any thoughts on this from anybody who has actually worked with HFA or knows about ventilation practices?

Thanks,
Inga

[erik winkler]

Inga,

You should have asked me, you know my emailadres.
For one I would place the fan on the other side of the acid table, so that you can blow the fumes out through the overhead door.

[Ingrid Mager]

Erik, that is exactly what I am showing in my diagram. I just don't have the directional arrow in there, but look again and you will see that is what I mean. It is better to pull the fumes out, than push them out from the back side. . .more controlled directional flow.
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I can't really build an enclosed area behind the overhead door to isolate the back of the shop from the front, creating a fume chamber of sorts, or I would. It gets complicated, because I am on an oxygen machine myself right now, and it is situated in the stairwell, so I NEED to make sure there is NO hydrogen fluoride vapor going that way AT ALL as it will get concentrated along with the oxygen. I also have oxygen tanks I can wear that I have retrofitted to assist in my tight fitting face mask with acid filters on it, but I still need to go in and out of that rear door up to the apartment, so the shop are MUST be vapor free.
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I know you did some acid work outdoors at one point. . . . do you still think that is the way to go? Anther skilled acid person suggested not to, but I think there is often more than one safe way to do things. I would like to work just behind the overhead door, but don't know if I can seriously draft the fumes out perfectly. What do you personally think?

I am waiting for a book on industrial ventilation design. Perhaps it will have something helpful in it.

~Inga

[erik winkler]

If it is so important to you, cut some hair (cathair could be used, just kidding) put it on iron ashtray or something and burn it.
If you smell it inside you know how or what, you do not need the book for this.

[Ingrid Mager]

That's an interesting idea. . . anything that smells strongly should therefore be able to be used to test with at least to some degree.

But if I recall correctly, you did not smell a whole container of HFA leaking out and up into the upper levels oF your building. . . .so always a bit of a worry with something so dangerous.Yes, it is that important to me. I do not need further damage to my lungs and just got out of the hospital last week for lung issues.

Thanks for the idea. I will try it. . .maybe just using an incense stick.
Inga

[Lee Littlewood]

Is hydroflouric vapor heavier than air or lighter?
Does anything change when the HF reacts with the glass?

What about a loose fitting lid over the etching pan, with a tube leading to a suction fan outside the roll door and the roll door almost all the way down?

[erik winkler]

Lee,
Good question I hoped someone would ask that.
What I have withnessed is that the 'smoke' of the acid goes up in the air.
But I also think it goes down, just to be on the safe side.

Inga,
The acid vapours are definatly smellable (I do not know if this is correct english).
With every smell, if you smell it for a long time, your brain will neutralize that impuls of smell.
It is like the smell of rotten eggs, if you are in the fumes for longer then 10 minutes, you do not smell it anymore and think there are no fumes...
Untill the concentration of the fumes are suddenly higher, then you smell it again.
In my building only a little bit vapourised out of the countainer over a period of 1 year.
I noticed it out by the glass jars that where in the cabinet, they were a little matt etched and my mica acid solution did not etch anymore.

Allways be safe then sorry.
Good luck.

[Andrey Kolmakov]

wow !!! how much info !!! Thank you all !!!!you are very kind !!

[Doug Bernhardt]

Ingrid....was an excellent time to bring up safety. Thanx for that.

[Ingrid Mager]

Lee brings up: "Is hydroflouric vapor heavier than air or lighter?
Does anything change when the HF reacts with the glass?"
--------------------------
Specific gravity of HFA = 0.97
Vapor Density of HFA = 2.21

Does this bear any relevance??

~Inga

[Ingrid Mager]

Perhaps this might of interest to someone:
I depend on supplemental oxygen in order to breath, so wearing just a regular mask with cartridges is not a possibility at this time. So here is what I did to bring in additional oxygen from a machine that is in my apartment space. (No hydrogen fluoride should enter the stair well because it will be concentrated and I will be breathing it in.)

Mask Augmentation.jpg (73.68 KiB) Viewed 18401 times

This is my retrofit for auxiliary air to a standard mask equipped with acid filters. I drilled into the plastic and shaped the hole with a conical grinding stone. Then I used rubber bushings to pad brass fittings. Works well.

And this is what I have done to my shop area so far to help reach my goal. Constructive comments very welcome!

My shop area.2 smaller.jpg (53.74 KiB) Viewed 18399 times

~Inga

PS - -Good document on HFA safety:
http--web.utk.edu-~ehss-training-has.pdf.webloc

[erik winkler]

Inga,
Can't help this, but I really would want to hear you say:"Luke I am your father" when you are acid etching the glass...

[Ingrid Mager]

Is that something from Star Wars?
Go ahead and laugh. It's okay. . . I probably come accross pretty goofy. But I will get there. . .
~Inga

[Danny Baronian]

Inga,

What's more important, acid etching or your health? Have you consulted your doctor?

Considering your set up - your living space above the shop, I'd seriously consider other methods of glass techniques in place of acid with your health concerns.

If you're still determined, check air flow, or more importantly, the rate at which the room is filled with fresh air, and how the fumes are evacuated, use a smoke machine, or a bee smoker, which burns rosin.
Ignite the rosin, pump the billows and smoke comes out and you see where, and how fast the smoke is evacuated with the set up you have. An open window up stairs would also cause a draw.

If it was me, and my health could be compromised, I'd skip the acid.

If you're concerned about the smallest amount, the oxygen mask hose connection alone is prone to leak.

You have one serious health issue, why ask for more?

[Lee Littlewood]

Ingrid's link is to the University of Kentucky hydroflouric acid safety list. It is chilling. I could not get the link to work, but I found the info via Google and made a Tiny URL that seems to work:
http://tinyurl.com/a4g8zh2

It does not say if fumes are heavier than air or not, but it specifically mentions working in a hood, which is a sink with a metal range hood over it, drawing air out of the room. So I think we can assume some fumes go up, which would be living quarters, no?

I'm still wondering about an etching pan like Eric's, with a lid that drops down over it when the glass and acid are in. Lid to be a bit loose, but with plastic tubing leading to an exhaust fan outside the space. They make little fans that fit inside dryer vent pipe, and it would not require a strong vacuum, just a constant pull to keep fumes moving outside. (I don't exactly know how one would rinse out the hose after use.)

[pat mackle]

From my experience the fumes in calm air are heavy and gravitate towards the ground. If you design an exhaust system, I would arrange the venting at table height and at floor level. Anything higher than that in a room space would bring the vapor to circulate at head level. If you have a normal sense of smell, your nose will immediately tell you that you are inhaling the faintest fumes. A strong shot of diluted acid will immediately shut your nose at mid breath followed by an instant flood of snot. I have also noticed that the fumes can make any recent small cut on your hand start to bleed again, as if the coagulation process reverses itself.
Unless you are really sensitive to these fumes while using this material at diluted etching mixtures, just decent air flow seems to be the norm for most embossers I've met.
You might buy some Ph papers, and just tape some strips at various levels and areas of the room and check them for any change in color for several days.

[Ingrid Mager]

My breathing has improved leaps and bounds since I first began posting on this thread! I had a lung injury in December, coupled with pneumonia and was not sure it was going to happen, especially up here at 10,200 feet where some people never really get acclimated . . .but it's getting better and I hardly need the oxygen compressing machine any more!!!!!!! <Major Happy Dance> Thanks for caring, Danny - I take those words as ones of kindness.

Pat, what a clever idea of pasting up PH Strips, you wise old fart!! (I can say that, because I am an old fart too now. . .just not half as wise as Pat).

I'm going to rig up a portable oxygen tank to supplement the mask if I feel I still need it. (probably a good idea) I don't want to open the upstairs windows or turn the exhaust fans on up there, as indeed, that will create a negative draw, (as Danny brings up) not to mention that the outside air could come flowing in before it has fully dissipated.

I also went to the local ER yesterday, talked to the physician that treated me last month and MADE SURE that they have calcium gluconate on hand and ready to go, should the unspeakable happen, not just ASSUMING they are supposed to have it.

I hope to post my first test pieces soon. Gotta admit I am still a little nervous, so just taking my time until I feel really confident and comfortable with my plans. . . .maybe even do a few dry runs . . .yeah. . .that sounds like a good idea. . .

Thanks for all the heartfelt posts!

~Inga

[erik winkler]

Is that something from Star Wars?
Go ahead and laugh. It's okay. . . I probably come accross pretty goofy. But I will get there. . .
~Inga

Inga you don't remember my darth vader acid suit.
I fulltime protect myself after my mishap with acid fumes.
Breathing through THE mask is hard and sweaty so I allways Say: luke I am Youre father when I am ready to go.
Do not forget that calcium gluconate only has a shelf live of just a few months.

[Ingrid Mager]

Aha! Well, that explains it, Erik. I can be a little slow to get it sometimes. Yeah. . . I kept a copy of you in your outfit where you look like a right valiant night! Mine "garb" is similar, only I don't look half as handsome as you do in yours - but I have an actual acid resistant suit under the apron and am putting red dye in my water.
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I think I will call the hospital ER about the half life issue and what they have on hand. . . JUST in case. I would rather err on the side of caution. In all the cases I read about where somebody has been mortally wounded, there has always been some safety precaution that had NOT been in place. . . . . .and/or delayed application of CALCIUM GLUCONATE GEL.

I also have another back up of calcium carbonate which can be made into a slurry and used from what I read. I do not know if it is as effective or not, but it seems to be yet another treatment for bodily contact from what I read in the HF SAFETY article I posted earlier in this thread.

~Inga

[Roderick Treece]

If I remember correctly calcium carbonate is what they make gym and rock climbing chaulk out of Any climbing store would have it. Don't know if it works on HF though.