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turkgeltz
01-03-2004, 11:22 AM
Does anyone have any experience with doing etching in glass and how to do it? diamond bit? speeds and feeds? Wife wants.......

steele
01-03-2004, 11:52 AM
I have no experience here BUT: Have you considered making a stencil over the glass and then blasting it with grit? Does she really need glass, could you use clear plastic?

BIG AL
01-03-2004, 12:47 PM
Coat the glass with a layer of wax, lay your template over the surface and start punching thru the template with a sharp stylus, next use needle to remove the wax between the punch marks, coat the surface with sulferic acid, let sand and then wash off with lots of water.Tip, go to a Tandy's store and get some leather transfers and follow the directions. (this is what I do as I'am only able to draw flys). Best of luck! BIG AL:)

turkgeltz
01-03-2004, 01:16 PM
Thanks, I'll have to give that a try!

High Seas
01-03-2004, 01:32 PM
Geoff Williams, in his book CNC Robotics took the following approach:
1. Plot the image on the surface with a permanent marker that resists etching paste, He found that the Pilot Metalic Marker (extra fine) would work.
2. Then added a border around the plot with a wider version to prevent "spill over".
3. Let the ink completely dry.
4. Read the safety warnings on the paste.
5. He applied the paste with a small piece of wood (bet the caustic stuff eats up the metal bits in brushes)
6. He let it dry for 15 minutes (plus or minus based on brand of etching paste).
7. Wash off the paste and then clean off the ink with lacquer thinner.

There's been a lot of plus/delta said 'bout his book. But this looks like it might work!

You might find all the bits to do the same thing at a crafts shop (Michaels or JoAnns - chain crafdt stores) or a stained glass shop.
:cheers: Jim
PS - if you want to buy the book - best bet I found was thru overstock.com

keithorr
01-03-2004, 02:15 PM
Originally posted by turkgeltz
Thanks, I'll have to give that a try!

Don't.

Sulphuric acid doesn't etch glass. Hydrofluoric etches glass. Very toxic.

High Seas
01-03-2004, 07:44 PM
ROGER THAT!
I did a quick teoma search and there are some good hits on MSDS (safety data) and other options/info on pastes etc. I'm still prone to purse the xyz pen and ink (read CNC) approach to glass work - haven't yet, but will soon - rather than deal with more bits, cutting speeds/feed rates, etc on a pretty tough medium!
Mind you I hand-dressed 2 marble countertops by hand - so an easy way is a better way! ;)
BUT - chemicals require care!
:cheers: Jim

keithorr
01-03-2004, 08:44 PM
The paste is a dilute floride based product. The thickener prevents splashing, and the low molar strength makes it safer to use than hydrofluoric acid.

The only problem with the paste is the etch can look patchy. Some areas more frosty than others. Reapplication doesn't always solve the problem.

Commercial glasses etch differently depending on the chemical composition of the material.

Most shops use sandblasting equipment. A fine grain of aluminum oxide with produce a lightly textured frost, closest to an acid etch.
Silicon carbide is much harder, and knocks very small chips out of the glass. (Easier to see with a magnifying glass.) Silicon carbide grit is better for deep carving.

DLMACHINE
01-03-2004, 09:19 PM
What about milling glass? Can it be done?

Konrad
01-03-2004, 11:01 PM
Would a Dremmel tool with a diamond bit work?
Konrad

BIG AL
01-04-2004, 01:04 PM
Well your right, I feel even dumber than usual. Sulfric I used to etch metal, not glass, same method only different acid. My first thought for acid would have sent everyone in orbit as it only comes in a wax container. I do remember a shop that used sand in a unit that looked very much like an air brush, but the guy that did the brush work was a true artist. "Anyway this group proves that this is the best site on the web for solid info." :D

DLMACHINE
01-04-2004, 07:45 PM
What if I wanted to make a 3D object out of glass how would you do this?

BIG AL
01-04-2004, 10:07 PM
JUST COULD NOT RESIST, BLOW IT! (SORRY)

DLMACHINE
01-05-2004, 09:49 PM
Funny BIG AL however are you trying to tell me that you haven't ever seen a solid peice of shaped glass. Not hollow blown glass?Nobody here has any replys or even a guess?

BIG AL
01-05-2004, 10:10 PM
DLMACHINE, I've watched the process , and know these folks do solid glass also. They do a melt and spin, forming as they roll the molten glass. If my memrory serves the New York area was home to many of the people producing this form of art glass. Seems like a good bet would be contacting a museum or art dealer and asking for a lead as this is a very special form of art. Hope this was a help. :)

HuFlungDung
01-05-2004, 10:11 PM
DLMachine,

Perhaps you could make a mold to at least pour a near net shape in glass. You might even be able to slump some plate glass together in a suitable oven.

You would likely want to anneal the glass very carefully, to prevent it from fracturing spontaneously when grinding it. I don't know what the Rockwell hardness of glass is, you might be able to shape it with carbide burrs on a real light cut, but diamond impregnated burrs would likely be the best.

DLMACHINE
01-05-2004, 11:20 PM
Thanks

lsfoils
01-06-2004, 09:52 AM
About a hundred years ago (ok, maybe a little less) I used to cut my stencils out of contact paper, used for shelving. Did the drawing, applied to the glass and cut it with an excato. Had to sharpen the excato a lot because glass is quite a lot harder than steel. Anyway, I would peel one panel at a time and blast the appropriate edge or surface and reapply the panel peel the next one and so on. Very tedious but rewarding. I always wanted a computer to cut the stencils for me because of course it takes a steady hand - seem to have misplaced mine. Someday, when my machine is finished, I'm planning on taking on this challange again. My computer art doesn't care where my steady hand is.

As to your question of carving, check with the stained glass people for tooling. More like grinding. I have beveled glass and its a trick to keep from cracking the stuff for the heat. Lots of water there.



Uh, 6 hours, 20 psi, 90 grit Olivine -Doug

DaSigntist
01-06-2004, 10:23 AM
Howdy,
In the sign business we use a vinyl material that simulates sandblasted glass we call "etchmark" (see photo below)
It is basically a sticker we cut with a knife cutting plotter.
Cost is (guessing) in the range of $5.00 per 15" X 3' and can be had in sizes up to 60" wide.
Awesome stuff which can be hand cut too.

Love the sandblasting Isfoils!

lsfoils
01-06-2004, 10:40 AM
Thanks DaSigntist,

This vinyl you talk of reminds me that I want to cut stencil in window tinting some day. Ever considered that when making signs?

Thanks again

turkgeltz
01-06-2004, 06:30 PM
Very nice pictures!!!! And I like all the different ways you can do it! I'm trying out cutting a image in plexiglass at the moment to see how it comes out and I'm thinking about trying to carve out a image in ceramic tile (12x12). I don't know if anyone's tried that yet. I think I'm just use a sharpened carbide bit at high speed. Any good advice on it or would you perfer the damage report?:)

High Seas
01-06-2004, 06:50 PM
Just finished laying a kitchen full of tile - and a marble counter top - water, LOTS of WATER. All my cutting was with carbide or diamond blades.
I didn't etch/carve anything - but there are a lot of finishing products available (best to always check good ole Harbor Freight first). Some folks have been engraving marble over on the Yahoo/Master5 group. Might be a hint or 2 there too.
:cheers: Jim

turkgeltz
01-06-2004, 07:20 PM
Thanks, maybe I'll check it out! I'm only going to go about .015 to.020 deep. Probably only enought to break the ceramic coating, I think. Experimenting, you know make 3 or 4 pieces of trash and then learn something neat that can be done from it!

foamcutter
01-09-2004, 01:02 PM
Check out this site www.luberth.com/plotter/ditwasplotter.htm I hope I copied that all down right. look down the links to Marty Harper 3d stone carving. may be some help there.