Best method for achieving a deep etch?

[Kelly Thorson]

I want to do a fairly deep etch for some angel gilded lettering, and I'm wondering if the best method to achieve what I want would be to sandblast and then acid etch to bring back the transparency.
If so, I have two concerns, first would the adhesive on the sandblast mask stand up to the acid? If not I would suspect that starting with a coat of asphaltum would be the answer.


Another unrelated question I've been meaning to ask is has anyone ever tried acid etching with one of the photoresist blasting stencils. Is it worth a try?

[Larry White]

Hi Kelly-
I've done some of this. Firstly, you can't get sandcarved glass to return to a polished state to get a mirror finish gild. It's more of a matte gild, but a bit brighter. Acid treatments to sand carved glass will smooth out the etched surface a bit, usually enough to do a chemical deposition, and make the etched surface a bit more translucent, but won't take it back to the polished state required for a mirror gild. I haven't tried angel gilding into sand carving. It would be worth a try. I have had success with copper, lead nitrate, and silver. Angel gilding is a little more tricky than silver or the other solutions. It doesn't always want to deposit right up to the edge, and this could be the case at the letter edges. Perhaps this is a good time for a test piece. I would be interested in the results. I have typically sealed the sand carving and water gilded it. Angel gilding would be quicker and cheaper...if it works. I would suggest mastering flat angel gilded mirrors before going exotic.

Secondly, you really don't want anything on your glass when angel gilding. Just deal with the raw glass, very very clean.

Perhaps Dave S. or Pat M. might shed different ideas regarding this. Pat would know about the photomask & etching. And... if no one has an answer for you, it's always worth a try.

Inverted embossing might work.

[Kelly Thorson]

Inverted embossing might work

Okay...and what is that?

And....I just realized that part of what I asked was a very stupid question seeing as how I would be removing the mask if I angel gild. So to avoid confusing others who are new to this I am going to edit my first post. You pros are still allowed to laugh at me.

[Danny Baronian]

To get a better visual answer of some of your questions, the Nov/Dec issue of Sign Business (may be wrong about the months but was recent) had an article by Dave Smith, that acid embossed a glass plaque for a customer. The text and accompanying photos explained the whole process very well.

As Larry said Pat needs to jump in concerning the use of a photo resist mask for acid etching, but they have a water base adhesive which would degrade when submerged in acid.

In this type of work, there are no short cuts. If your still curious, the best thing to do is .... a test.

[Sarah King]

I realize that this is an old thread but I've been looking into the question of getting the Angel Gilding to go right to the edge of the glass. The secret is to pour on more tin - even let it run over the edge some. You might have a bit more cleaning to do on the face of the glass when you're done but it's worth it. Don't make the tin stronger and don't leave it on longer just use more per square foot. Scimping on materials is, in this case, a real mistake.

[Raymond Chapman]

Kelly - we have cleared some areas that have been deep etched and it brings back some of the brightness but not nearly as much as the clear glass, of course.

If you gilded over that it would have a matte finish, but not nearly as dull as if you had gilded directly over the etched glass.

Sarah is the expert on angel gilding, so what she says is probably law. I haven't done any angel gilding over deeply etched glass, but what others have said seems logical.

[Doug Bernhardt]

It might also be that Kelly is looking to achieve the look of brilliant cutting...in which case that is the only way to have mirror finish in deep blasting..one way or the other this otta be interesting!!

[Kelly Thorson]

Thanks for all your comments/information. I realized I got sidetracked on this one, real life does have a way of cutting in on my fun time.
In any case - the project is still in the plans, actually it is sitting by the blasting cabinet so when I get on it I'll let you know if I find anything interesting.
Oh and Doug...please don't get me headed off on anther tangent....I've already used up this lifetime and more.