Making ElectroEtch stencils

K

Ken H>

Joined
Dec 31, 2011
Messages
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Hello all - I know there are several of ya'll who make your own stencils. I have a couple (few?) questions. I'm using IMG stencil material and their developer. When the stencil material comes out of package it's a light blue/green and fairly transparent (I cut a small piece in dark room with low level yellow light only). After laying in direct room light for a few hours it turns a dark opaque blue. While working in dark room (low level yellow light only) I place stencil material on black rubber mat (bottom of mouse pad), lay transparent logo on top, lay glass on top of all to hold flat. Then expose to a 100 watt incandescent light bulb in reflector held 2 to 3" away from glass. I've exposed for several different time periods with differing results. After exposing to light, film covering is removed from both sides before placing in developer.

My questions,
1. Should exposure be long enough the logo image will be visible after exposure but before developing?
2. Should the stencil turn almost opaque dark blue after exposure? OR, turn dark only after developing?

Thanks for any suggestions and help,

Ken H>
 
OK, I've learned a bit more..... I think anyway. I've read these IMG stencil materials should still be on the green transparent side after exposure, turning opaque blue during developing. If underexposed it should be be almost clear after developing. I've looked at my stencil material, it's greenish/blue transparent out of box. With no exposure, after 6 minutes in 100F temperature developer the stencil is exactly the same as out of box. I think I've got a problem with the developer solution.

Ken H>
 
Posting to correct info in previous post (per IMG) - Not sure I've really learned anything at this point, but did have a good phone chat with Patrica at IMG. After discussion, she assures me my developer is NOT right for some reason. They are sending me a new batch of developer.

What I did from Patrica and another guy I talked with at IMG, is the emulsion (rubbery texture) on each side of stencil material should turn dark blue under exposure light, but emulsion under image will stay pre-exposure color. The stencil material does NOT get darker in developer. Expose until the image is visible on stencil material, then put in developer to "fix" the emulsion (dark blue background) and dissolve the unexposed emulsion on each side of "fabric".

I should be getting the new developer (correct I hope) Friday or Sat (I hope) and will be able to say more a few hours after I get package.

Ken H>
 
OK, I got the new developer Sat and got a chance to play with it some Sunday and today. New developer works! Dissolves the emulsion just as it should. I find a short exposure of around 30 seconds with the 100 watt flood light type bulb I am using. I may go to a standard 100 watt light bulb for longer exposure - not sure yet. That will take more testing. The font used MUCH make a VERY dark image - not allow ANY light thru. The amount of exposure will slightly darken stencil material but leave a light display of image on stencil material.

I warmed the developer to around 100ºF (warm to touch), developed for about 2 minutes - I think less time will work, more testing required. making sure to remove covering on BOTH sides of stencil material. Using scotch tape to remove thin covering helps. Developing will quickly remove the emulsion from both sides of stencil material. Rinse good, dry, and the quick test gave results below. Still need a bit more work, but think it's going to be ok.

The text is 1" long, with about 1/8" letters. The zoomed in close up makes it look larger than it really is.

StencilTest_zps2bbfe8cf.jpg


Ken H>
 
Looks good Ken. Can you clean up the edges a bit with a fine grit sand paper? Also, how many etches are you getting per stencil?
Thanks.
gene
 
Gene, I think the "grain" you're seeing the edge of letters is the rough finish of metal. For an etch on a blade I like to have at least a 400 grit finish and prefer 600 or better. A nice satin (or mirror) finish really helps to have sharp edges in etch.

How many etches? Heck if I know - remember that's the first successful stencil I've made. Only the 2nd stencil I've tried since getting a real developer. Wasted a LOTS of stencil material working with the liquid IMG sent for a developer - I think it was some type of electrolyte. After IMG sent correct developer, it's working now.

With a stencil I got from Ernie I've made 50 or so etches and stencil still looks good. I burnt the first stencil from Ernie, but the 2nd is lasting good.

Ken H>
 
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