Building a Etching machine

SAR

SAR

Joined
Aug 15, 2005
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The tutorial is up in one of the stickies.....good luck and remember to use common sense in all facets of life

Spencer
 
So for those of us that don't know anything about etching what do you have to do once you have the thing built to etch a design in steel? I mean I know you have to attach the lead to the blade to let the current run through and put some sort of stencil for your design and then place the other lead on top, but is that it? Do you need some sort of etching solution or something and what do you use as a stencil?

Sorry for my ignorance in this matter; being that I have a degree in chemistry you would think I should know the answer but it's amazing what you forget when you go into a different field. I'm guessing you need some sort of acid or something.
 
You will need a stencil, an electrolyte (some people just use salt water), and a felt pad or other sort of pad to run the charge through which is soaked with the electrolyte.

No acids are needed, though commercial electrolytes can be caustic because of the various salts in them.

There's not much to it really. A DC etch will do a deep etch, removing metal (depositing it in the electrolyte soaked pad) while an AC etch will deposit oxide. Many people will do a DC etch first and then swap to AC for another period to get a nice deep etch with a black look. Personally I like the more 'frosted' look of a deep etch without any blackening.

Some etchers (as mine have) have an option for an intermittent / stuttered current in order to increase the life of a stencil and prevent overheating.
 
Justin.Mercier said:
You will need a stencil, an electrolyte (some people just use salt water), and a felt pad or other sort of pad to run the charge through which is soaked with the electrolyte.

No acids are needed, though commercial electrolytes can be caustic because of the various salts in them.

There's not much to it really. A DC etch will do a deep etch, removing metal (depositing it in the electrolyte soaked pad) while an AC etch will deposit oxide. Many people will do a DC etch first and then swap to AC for another period to get a nice deep etch with a black look. Personally I like the more 'frosted' look of a deep etch without any blackening.

Some etchers (as mine have) have an option for an intermittent / stuttered current in order to increase the life of a stencil and prevent overheating.
Click to expand...

So what material should you use as a stencil and how thick should it be and where's a good place to get high quality electrolyte needed for etching?

And anybody got easy ways of stencil designing?
 
www.tustech.com is who I would recommend for getting a stencil done. They have a 22$ art / setup fee, and then it's 13$ for a 2.5x7.5" sheet of stencils which for a knife sized stencil should have 5 individual stencils on a sheet, and each of the stencils ought to last for a couple hundred deep etches if care is taken with them.

The stencils are made from a fabric screen with layers on each side of another insulating material, that way you can have designs with 'floating' elements. If your logo is very simple, and doesn't use letters that require floating elements (like A O D etc, where the center would be 'detached' if you punched that letter into a piece of paper) then you can just cut a stencil out of a piece of vinal or electrical tape.
 
Hey thanks for the good tips guys!!! I was about a week away from buying the Etch-o-matic but this sounds like a lot better of a setup! Thanks again!
 
That is a good tutorial.

I make one suggestion though, replace the transformer with a variac.

You can then dial in the etch to work just right for you, and anodize titanium with the same rig!

Edit:On second thought, we should all buy Etch-O-Matics for etching, and get anodizers from reactive metals...
 
the etcher i made is from a realy old ac voltage controler i got at a thrift store. huge nob and dile to show voltage. thats conected to a masseve step down transformer. so i have a range of 0-50 @ 15-20 amps. now to add an anodizer would i just not use the step down transformer and turn the ac to dc. the main controller goes from 0-150ac at 6-10 amps. so put a rectafire on the ac line to get the dc needed.
 
How are you designing your logo, what kind of program are you using? Or do you just tell TUC what you want and they design it for you? I am very interested in doing this. Just at kind of a lost on exactly where to start. Thanks.
 
As far as stencils go they are quite easy to make on your own. The first thing you need is a design. Simple black line designs or text work best for me. You can do the text using microsoft word and more complex designs in Adobe Illustrator. After you have your design you will need to print it out on transparency film. I use my laser printer to print my design onto the transparency.

You will need some Raw Stencil Material and an exposure unit to expose the stencil. I get my raw stencil from IMG (international marking group) and also the developer (also from IMG) for the stencil after exposure.

My exposure unit is simply an old scanner that I gutted and put a flourescent lightbulb into. I found that the new bulbs that are spiral design tubes do not work at as well as a straight tube bulb to evenly exposing the stencil material.

To expose the stencil I put the transparency on to the scanner glass followed by the un-exposed stencil and close the cover. BTW, I also found that I got better results by adding a piece of black construction paper to the inside of the scanner top rather than the white reflective inside. :confused: Anyway, next you expose the stencil for 2 minutes, take it out and put it in the developer mix for about 8 minutes and agitate.

Stencil complete :) It is very simple and the stencils last for a good long time and will etch many knives. If anyone would like pics or any tips please ask and I will supply the info ;)
 
Tommegow said:
OK what is a Variac?
Where does one get one ??
Will it fit in the tutorial box ???
Click to expand...
It is a variable transformer...

Google can be your friend on matters like these...

No, it will not fit in THAT box, but if a solution cannot be worked out for that minor problem, we probably should not be building this project....
 
I was going to ask about what the variac does myself, but since that question is posted, can someone explain the bridge rectifier, and if they neem to be matched to the power supply or can you go oversized and be safe.

when i was first looking at etching, I stumbled upon an old Model train transformer that I snagged real cheap. it had adjustable voltage(0-18V) so I figured it would be perfect. then when fiddling with t, I discovered that the voltage was AC, not the DC I'd assumed. so I know I need to convert it's output from AC to DC in order to etch, which i understand is what the rectifier does, but don't know if I need to buy a special one, and well the radio shack people today are not the helpful people they used to be for this kind of thing.


Also, what modification allows the unit to anodize?
 
KnifeWerks said:
It is a variable transformer...

Google can be your friend on matters like these...

No, it will not fit in THAT box, but if a solution cannot be worked out for that minor problem, we probably should not be building this project....
Click to expand...

Sorry I can buy a bigger box but thought I'd ask my stupid question before I ordered the items
 
A bridge rectifier does exactly what it's name says. It provides a "bridge " with two, one way lanes on each side. It is composed of four diodes arranged in such a way as that each cycle of AC allows a positive current to flow at all times (if only two diodes were used it would be a half-wave rectifier ,and make pulsed DC current), thus converting the AC into DC . Just as with a real bridge, capacity is restricted by maximum usage, not minimum. If you put a 10 Amp rectifier on a 1 amp circuit - no problem. Other way around - smoke.
Stacy
 
Tommegow... just reread my earlier response, sorry if it seemed rude, I didn't mean it that way.
The only stupid questions are the ones we don't ask...

Kindyr
Running it on DC allows it to anodize.
Varying the voltage allows you to do more than one color.
You need to be able to go up to about 100V to be able to get all of the spectrum on Titanium. 18V isn't high enough to really get useful colors, blues for example are in the 20s...

I am no electronics guy, but I went with a 6amp 200V rectifier myself.
The electronics guys assured me bigger is better when I was building mine...
 
SAR when reading the tutorial from the link you posted it listed a transformer to use. With all the advice given in this thread did you still use that one or a different one.
This is the one by cat. number in the plan set:

25.2V CT 2.0A Heavy-Duty Chassis-Mount Transformer with Lead

Is this another one of those times that bigger is better?
 
is there any reason you couldn't do this with a tabletop 13 volt DC power supply? (granted, you won't have the ac option, but i HAVE 3 bench 13 volt power supplies)
 
most table top power suplys are just tranformers with some diodes to change the ac to dc. take one apart and run wires to the transformer. then you have ac and dc.
 
so aside from a switch and some wiring to give me the ac/dc option (never thought I'd go THERE), - and the fittings- i've got an etcher already....?
 
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