Another Electro-Etch Question for Bob

Bob, I've been to your website and I've made both the electro etch unit, and the stencil developing box. I've also received my stencil material, and I've made a stencil with my mark. The stencil came out nice and sharp.

My problem is that I don't know how to properly use the electro etch unit. I'm using the electrolyte for "All Steels" from IMG. When I tried to etch my logo onto a piece of steel, I pretty much just burned the stencil up. I set the unit to "DC" and I would put the pad down for about 2 to 3 seconds and remove it for a few seconds. It didn't look like anything was happening but my stencil melting. The blade would start sizzling as soon as the pad touched it. After a few times I switched to AC, but it was pretty much too late.

One thing that I don't know is how to use the electrolyte. Do I just soak the felt pad down before starting the etch? Also, what kind of felt should I be using. I'm currently using the sheets of felt that you can get from Wal-Mart for about $0.20. Do you think my etcher could be putting out too much current? I made it using all of the Radio Shack part numbers that you supply on your web site. One more thing, how long should I wait before using the stencil after I take it out of the developer?

Please tell me how I need to go about using the electro etch unit correctly.

Thanks for the info and for your time. -chris

Chris,
I can't answer all your questions, but I think I can help some.

When using the electrolyte, just put enough on the pad to leave a damp spot on a paper towel when pressed down lightly.

When applying you stencil to your blade make sure it is secure and laying snug against the blade.

As far as the felt material you are using I am not sure. If you will email me your address I will drop some of the material I am using in the mail to you.

I use the felt from Walmart. It is white. You say you are using "Sheets" and I am not sure what sheets you are talking about. The stuff I use it back with the cloth where they sell material for making clothes and thelike. The felt comes about 3' wide and as long as you want it. You buy it by the yard. I just buy one running foot (1 yard) and it lasts forever. Then, like Mike said, just get it damp, not wet.

Did you get any mark at all? If not, your stencil may not be correct.
Did you get any marks where you did not want them?
Is it possible you are touching the steel without going through the stencil?
Have you verified all of the wiring? Try using a VOM to test the output of the machine.
Are you sure they gave you the right transformer?
What is the output voltage on AC and on DC?
What is the ampherage output of the transformer?
This etcher works fine for a lot of people so I doubt if it is the problem if it is built correctly with all of the parts. All things being done correctly, it sounds like you are getting too much power. (I can't believe I said "Too much power", ARGHH).

Verify all of this and let us know what you find out.

Thanks for the response. I went back and checked the parts to my etcher and they were all correct. I also experimented with the stencil some, and it looks like it was melting because I had not exposed it long enough. I added two more minutes, and it held up much better.

Now for a question. What is the effect of over-exposing the stencil to the light? Will fine lines receive some light and not develop correctly?

Another question: Should I use fresh developer every time I develop a stencil?

One more question: How long should I etch on DC, and how long on AC?

On my last try, I was able to etch a logo on a test blade. The image was not as sharp as I would have liked. When I cleaned it up with a little sandpaper, some of it got sanded off.

Thanks again for your help!

-chris
www.chriscrawford.com/knives

You asked: "What is the effect of over-exposing the stencil to the light? Will fine lines receive some light and not develop correctly?"
Yes. If you leave the stencil exposed to the light long enough it will expose the fine lines and they will not "Develop" properly.

You asked: "Should I use fresh developer every time I develop a stencil?"
Yes. Mix just enough to develop whatever you need at the time. If you are making two stencils at the same time, one batch of developer will be fine but use fresh stuff each time you set up to make stencils.

You asked: "How long should I etch on DC, and how long on AC?"
This is variable. It depends on how deep you want the mark to be. Remember that DC removes metal so start on DC first and try about 3 seconds each for 5 times and see how it looks. If you want it deeper, try 7 times next try. AC is what turns the mark black. It removes metal on have of the cycle and puts it back on during the second half of the cycle. Do it just like the DC part, put it on for a few seconds and remove, repeat several times and it should be black. I then wash it with TSP to neutralize and then let it set for a while before buffing or anything. If the oxides don't set up, they will buff away.

You said: "On my last try, I was able to etch a logo on a test blade. The image was not as sharp as I would have liked. When I cleaned it up with a little sandpaper, some of it got sanded off. "

You probably did not etch deep enough. Sometimes if the pad is too wet, you get what looks like stains around the mark, these can be cleaned up by sanding or with the buffer.

I was showing my knife maker neighbor how to make an etch and saw a couple things he did wrong that hasn't been mentioned yet. In no particular order:
Keep the contact surface between the stencil and the knife dry, in other words, no etch liquid left from your last test. Too much liquid where it doesn't belong lifts the stencil, gives a fuzzy edge and a halo or dark marks where the current follows the liquid.
Don't press down hard, a light touch will do fine. Too hard and you press out the liquid.
The stencil has to be flat on the steel. This isn't easy on a hollow ground, but it can be done.
Clean your stencil between uses by using DC (removes metal) on etch liquid moistened wick pad with a gounded piece of metal. (Like you are trying to etch the wick pad)
Your etch pad shouldn't be dripping wet, but it has to be wet enough to conduct the electric current.
Tape the stencil down so it doesn't move at least two sides and four sides if you have the patience. Remember, flat matters. Use plastic electric tape or blue painter tape. Typical masking tape gets wet and will etch through leaving a halo around your stencil if it is small. I use quality blue painters masking tape.
Nuetralize right after you etch (baking soda/water mix if you don't have nuetralizer), if you don't rust shows up in a few days. Nuetralize and clean your stencil when you are done or it gets crispy and cruddy in a hurry.
Now can someone will tell me how to spell nuetralize?

How do you guys address the problem of hollow ground blades? I think I have seen one suggestion of putting some foam rubber between the metal plate and the felt, but I wonder if this might affect the conductivity any?

Unless you have a severly hollowed out blade, you should not have a problem. The stencil will curve to fit the radius of the steel. The felt on the pad will make up the difference since the difference is very slight. I use a 10" contact wheel and my pad that I use for etching is only about 1/2" wide so there is not much curve to worry about. If you had a really tight radius to work with, I would radius a pad to match.