Radio Shack does not have the process I'm looking to do.
I already have the PnP blue paper, but I can't get a sharp enough image. So someone suggested I try Ultra Violet light, but I need the emulsion. Radio Shack does not carry it.

As I said earlier, photo-sensitive resist emulsion is available form silk screen suppliers, as it is used extensively in the screen making process. Since I don't know exactly what you're trying to do I can't be too much more specific about possible techniques or materials. If you're having problems with getting a sharp enough exposure on your resist you may need to go to a process that uses a film positive. If yo udo, be sure that you create the positive susch that it goes against the resist with the emulsion or printed side against the photo-sensitive resist. If the positive is produced so that it goes against the resist with the printed side away from the resist, you can get light bleeding around the edges through the transparent carrier film.

I always used the sun to expose my resists for photo etching or photo screening, as the sun is pretty much a point source light and you get no diffusion with it. UV lamps have to be used much closer to the film and you risk diffusion.

Hope this helps.

Wow,am I ever learning some good stuff here.
Frank

Maybe it is too late for my reply, but I was wondering how you made your image for your PNP paper test? If you make a copy and another copy till there are no grays in the image, the edges will be black and crisp enough to etch metal. You have to keep re-photocopying until the grays are gone. PNP does not show gradiated grays well.

I use to teach metals and we etched all the time. I have not done UV exposure etching since back in the late 90's.
That stuff is wicked and it needs to be baked in the oven for so long to activate the emulsion. I did it with Tyler school of Art's power etcher years ago.

Don't forget to turn the metal upside down with wax at each corner to hold it up off the pan, if you do it that way. Or tape it to the side of the pan.

Anyway, to find those chemicals...do a google search or check with a University/business that does commercial etching.

Kim

make a plexi-glass container. Use acetone to seal it together install a small aquarium bubbler and make it to where you have a place to slide another piece of plexi into it that you tape the copper on. Use the press n peel -copy your image on it and apply positive or negative. You can get the chemical at Radio Shack. You should get a good bite. The longer it stays in the better the bite. I took a class from Gretchen Goss on enameling. She had a huge etching container that she had made with a larger bubbler. The process works well. The items to be etched should be vertical not horizontal

Stefani,

YOu mentioned "sealing together" the plexiglas with acetone. I'm assuming by that you mean gluing the plexiglas together. If so, I would suggest that methylene chloride acrylic cement is a better substance to use than acetone. It is available in consistencies form water-thin to heavy-bodied and creates welded joints that are as strong as the material itself.

For joints that are perfectly fitted, the water-thin glue will flow into the joint by capillary action, leaving a joint that is nearly invisible. For joints that don't fit perfectly, I suggest using the medium or heavy-bodied cement as they have some filling action.

Rich

Am sure am replying too late, But the problem here i see is right equipment, am from Nepal, we do lot of etching work using dual jet etching machine and double surface exposure machine, we bought these machines from China www.ideafactory.co.in
these machine are capable of exposing even a hirline accurately.
To understand the concept of printing of positive all you have to say is you need a positive (offset)
Then how to find out which way it is printed the answer is very simple
use any sharp tool, may be a blade or needle and try to scratch the outline if it get scratched it means it has been printed from this side
I hope it helps

Call J-Tron, Inc. in New Jersey.

They carry a complete line of photo etching and PC board supplies.

www.j-tron.com
201-398-0500

Jake,

You're right; more surface area means bigger tank and bigger power supply. It is a function of current density, i.e. amperes per square foot. For a big piece like that you might consider using a DC arc welder for the power supply. Big etching tanks are pretty easily made from sheets of polyethylene if you have a plastic welder (they're relatively cheap - see HF).

I sincerely recommend you set up to do any etching outdoors, both for the ventilation for you and to prevent condensation of etchant vapors on your tools, which will cause serious rusting problems.

Rich

Thanks Rich for the suggestions, especially about doing it outside. I would have done it in my shop without it and been crying to everyone here about my rusting equipment. Saved me a lot of heart ache. I'll look into that plastic welder.

Jake

Jake Balcom
Mettle Design
Lincoln, NE