Slightly OT--Glass etching paint?

You can buy it at craft and art stores .. also glass shops.

Do they really use actual glass on those things, not some acrylic / polycarbonate?

Pete C.

I've never seen anything like that in a spray can but there are many sources for cream or bottled paint based products

Hopefully their fingers fall off from HF burns

If you google "glass etching spray paint" you get more hits about grafitti and laws than you get vendors

The nice thing about HF is, that it will stop those ar*eho*es from destroying other's goods. Sooner or later.

Nick

We had a spate of this in Denver a few years back, apparently the perpetrators were caught and put away because there hasn't been any more incidents that made the papers. IIRC, it's a craft item used for decorative glass etching and does contain HF, it's a gel or paste, not paint. Try an artist supply place. There's some type of wax used for masking-off when used for its legitimate purpose. Coat the glass with wax, selectively remove in the desired pattern and then etch with the paste. The stuff has been around for a long time, I've got an old('20s) scientific glassblowing book describing how to use a special paste for etching graduations into work. It had to be ordered from Germany back then, not something just anyone could make up from household chemicals.

They were hittting big plate glass store windows here. Polycarbonate might be resistant to it, although there's other issues with using that for windows. Probably got them for felony property destruction since those big windows are really spendy. Usually graffitti is a misdemeanor when they can catch them, the cops made an extra effort in this instance. Probably used security camera footage, but the news never said how they were picked up.

Stan

Try here:

They say the etching can be removed with a glass scratch removal machine. Sounds like a buffing pad.

Once at a car show I was admiring a sample of custom etching on automotive glass, and was told that it was done with a mixture of hydroflouric acid and lanolin. I have no idea if this could really work or not.

Mike

Ammonium Biflouride

Might be able to polish it out with rareox aka cerium oxide.

Craft stores sell it. It is an alkaline not acid. I did some mirrors with it. pretty safe. now sold only from locked bins to adults here in san diego

The easiest way to prevent large expensive windows from being trashed is to apply tint film. Mylar is impervious to this stuff

Proly should be sold to adults only after psychological testing. :)

I don't know what the ingredients are, but indeed the big art supply houses have it, mostly under Delta PermEnamel, or some such thing. Comes up pretty quick w/ google under "glass etching paint". Not sold as a spray, btw.

HF in a cream ought to work, altho from the little I have seen, its etching is more of a nice light frosting. The cops used to use it, to etch vin numbers on auto window glass.

This other stuff leaves quite the caked-on unsightly blob. Imagine if our idiot youth actually put what's left of their minds to something constructive/productive.

To be more specific, Hydroflouic acid is an extreme posion. Slight exposure will cause death by removing calcium from the blood stream. Lack of calcium causes a heart attack. Death is not immediate (a few hours), but it is irreversible.

That's what death is known for. :-)))

Ni-SCNR-ck

Maybe this stuff would work:

I had a jug of it when I was in the marine hardware business, but avoided using it except when absolutely necessary. And that was in the pre-MSDS days. It contains HF and nitric acids.

Ned Simmons

A little over-stated, I suspect.

People get burned in labs by HF all the time. No big deal, morbidity-wise.

But, HF is a peculiar acid, due to small atomic sizes of the atoms and their high electronegativities. HF is in fact a relatively *weak* acid, but the burns/tissue damage that it can cause are particularly irksome and nasty in part because it is small and relatively weak. Here's why: Because it does not completely dissociate (definition of a weak acid), and because it is small, it gets absorbed fairly readily into cells as an intact non-ionic molecule and then dissociates (ie, acts as an acid) *inside the cell*, causing real shitty hard-to-heal ulcerations.

These same properties may be quite related to why HF etches glass, but, say, HCl does not. Proly a really interesting mechanism, whereby the small HF molecule is able to sort of intercalate between Si and O, and the higher electronegativity of Fl over O then takes over... mebbe....

Nitric acid is also an interesting/complicated acid (an oxidizing acid), so I can only imagine the combination of HNO3 and HF that someone mentioned. FYI, aqua regia, a mixture of HNO3 and HCl, a really noxious combo, is what dissolves gold, platinum, and proly a couple of other heavy metals.

Or so I learnt. :)