Electrolytic Etching, For What A Dremel Can't Do 242
Dustin writes "A lot of people modify computer cases, often requiring them to cut intricate custom designs in
sheet metal. For most, there is the Dremel tool. But
sometimes, that just isn't good enough. Possibly due to an insanely complex design, or
unsteady hands, a Dremel just might not cut it (pun honestly wasn't intended). JimBob, a member at OverhauledPC.com, has a much better way. Using
readily available salt water and electricity, his technique is much easier than trying
to cut patterns with a rotary tool."
Coral Cache, just in case... (Score:4, Informative)
Here's the Cache Link [nyud.net] if it's needed.
Slashdot Kicks In (Score:3, Funny)
Rats! I wanted to see how this works - suprise my boyfriend by etching the fenders on his 69 Mustang
2 cents,
Queen B
Re:Coral Cache, just in case... (Score:5, Funny)
Re:Coral Cache, just in case... (Score:2)
Dremels are bad web server too (Score:2, Funny)
My guess at his method... (Score:5, Funny)
The site is down. Therefore I will assume that he poured water over the case and shocked the shit out of it.
You could get some interesting burn patterns that way. You might even match your case.
slashdotted already. (Score:3, Funny)
I promise you'll get lots of Karma for it!
Re:slashdotted already. (Score:5, Interesting)
Re:slashdotted already. (Score:3, Funny)
The Mirrordoor? Is it like the door where you see your self coming into? It only managed to cache the introduction page of the website.
Re:slashdotted already. (Score:2)
Wait a minute. (Score:5, Funny)
First off, there's nothing a Dremel can't do.
But since your alternative involves electricity, water, and chemicals, we'll forgive it. (But next time, could you kindly use something more dangerous than sodium chloride? We've got reputations to uphold here, and if the case mod weren't so danged cool, we'd feel we were slipping.)
Re:Wait a minute. (Score:5, Funny)
Try it without the chloride.
Re:Wait a minute. (Score:5, Funny)
That, or NaCl sans sodium. Gotta love those chlorine fumes.
Re:Wait a minute. (Score:2)
Re:Wait a minute. (Score:2)
Re:Wait a minute. (Score:2)
Re:Wait a minute. (Score:3, Informative)
And chlorine isn't good for the metal either. If you are interested in preserving the mechanical properties (especially the surface properties), using chlorine in an electrolytic metal removal process is a bad idea (in general, any electrolyt
Re:Wait a minute. (Score:3, Interesting)
Re:Wait a minute. (Score:2)
Re:Wait a minute. (Score:5, Funny)
Welll, let's be fair, here, there _are_ some things that a Dremel can't do. But that's what duct tape and/or WD-40 are for!
Re:Wait a minute. (Score:2)
There's always hydrofluoric acid for etching true glass side panel insets (cover the entire glass with a thin layer of candle wax, scrape away the wax cleanly from areas you want eteched, wash away the acid carefully, melt/scrape away the remaining wax). Here's at least one site [fundy.net] with more info.
Of course all the appropriate warnings apply as to the caustic nature of acids, fumes, potential for damage to clothes, skin, etc... Oh, and don't try this on plastic/metal
Re:Wait a minute. (Score:2)
Re:Wait a minute. (Score:2)
Sodium chloride is just to allow the current flow. The real power is Water!
How?
Oxygen does the cutting. Hydrogen gets emitted into the air, mixing with air oxygen, creating high explosive in your room
Enough for "reputation to uphold"?
Re:Wait a minute. (Score:2)
Excellent... (Score:5, Funny)
What about what a Dremel CAN do? (Score:5, Funny)
The 2005 Darwin award goes to! (Score:4, Funny)
Re:What about what a Dremel CAN do? (Score:2, Funny)
Our lives would be so much duller without them.
mirror (Score:5, Informative)
"much easier", where's the fun in that? (Score:4, Funny)
Re:"much easier", where's the fun in that? (Score:2)
Re:"much easier", where's the fun in that? (Score:2)
I want one.
Re:"much easier", where's the fun in that? (Score:2, Informative)
Re:"much easier", where's the fun in that? (Score:2)
Re:"much easier", where's the fun in that? (Score:3, Interesting)
Re:"much easier", where's the fun in that? (Score:2)
To summarize... (Score:5, Informative)
You take two plates of metal and hold them parallel (not with your hands, they're going to be electrified!) underwater. Electrify the plates and the positive ions in the water will collect at the negative terminal and the negative ions will collect at the positive terminal. By adding some salt to the water however, you can encourage a chemical reaction to happen at a given electrode. By covering the metal with paint or duct tape, you insulate it from this effect. So what they're doing is, essentially, painting around the hole they want to cut, leaving the hole itself barren, then submerging it in saltwater and electrifying it, causing the exposed metal to oxidize and be eaten away.
It's roughly the opposite of electroplating, which is the procedure which this technique is likened to in the article. Instead of trying to accumulate more on a given electrode you're trying to reduce the amount of matter present there.
Re:To summarize... (Score:5, Informative)
By adding some salt to the water however, you can encourage a chemical reaction to happen at a given electrode.
No, the salt is to reduce the electrical resistance of the water and create a greater current flow. Pure water actually has a high amount of electrical resistance. Oxygen will collect at the positive electrode, and hydrogen will collect at the negative (the article author is a bit confused and thinks this is methane).
You're correct about the rest of your summary though.
Re:To summarize... (Score:2, Informative)
Chlorine gas is poisonous. Fortunately it's heavier than air so it shouldn't fill the room or anything. Sodium hydroxide is caustic.
MJC
Not H2+O2- H2+BLEACH! (Score:2, Informative)
The 40% solution mentioned in the article probably limits the strength.
Keep it off of your 501's or we will know you can't use a Dremel tool.
From: Electrochlor.com [electrichlor.com]
1.2 Reactions
The principle reactions occurring in the electrolytic cell that produces sodium hypochlorite are quite simple, as shown in the following:
Oxidation of the chloride ion occurs at the anode:
2Cl- -> 2Cl2 + 2e-
Followed by
Re:To summarize... (Score:2)
No it doesn't. Water auto-ionizes into H+ and OH- ions at a low but detectable concentrations. Pure water has a resistance of about 18 megaohms/cm but it is fairly hard to keep at that purity. For example a platinum electrode will dissolve slightly in pure water and contaminate it. An iridium-platinum allow doesn't I think.
Re:To summarize... (Score:2)
I just said that water naturally auto-ionizes to H+ and OH- ions (actually the actual structures are more complex but they are still ions). Even if you can
Re:To summarize... (Score:3, Informative)
Someone modded that up? (Score:2)
'Pure water actually has a high amount of electrical resistance'
and to this you respond:
'No it doesn't, it has a non-infinite resistance'.
Since when did 'high amount' equal 'infinite amount'?
The Germans have a word which fits you very well. Besserwisser, which translates as 'faultfinder', 'know-it-all' or 'smart-ass'.
Re:To summarize... (Score:2)
methane gas???? (Score:2, Informative)
Re:methane gas???? (Score:2)
Re:methane gas???? (Score:2)
A typical alloy used in sheet steel is known as "1020", which has an average carbon composition of 0.2%. If you get methane there will not be much, even if the formation of methane is favoured over hydrogen.
You can buy machines that do this form of cutting which work in a kerosene bath. The kerosene evaporates (and also turns to black sludge on the bottom) so you have to take care that the arc doesn't happen at the surface of the liquid, or you could get a fire - which is probabl
Re:methane gas???? (Score:2)
2H20 -> 2H2 + O2
You're not going to evolve methane (as the article says). Sheesh.
Re:methane gas???? (Score:2)
And the metal isn't going to do anything. And methane won't show up in any possible form.
Re:methane gas???? (Score:2)
Re:methane gas???? (Score:2)
But H2 still goes up and likely boom.
Effects to look into (Score:2, Funny)
Salt + Electricity... (Score:2)
Re:Salt + Electricity... (Score:2, Informative)
Unfortunately, I was unable to load the article - so I can't comment on the procedure involved. But if you haven't studied electrochemistry to at least a small extent to know whats going on (and I know people with B.S. in chemistry I wouldn't trust with understanding reactions in this catagory), its best you D
Re:Salt + Electricity... (Score:2)
Dremel Casemod (Score:2, Interesting)
Re:Dremel Casemod (Score:2)
Spockdot Effect (Score:2)
Scotty: He's dead already, Jim.
Can also be done in a much simpler... (Score:5, Informative)
FeCl3 is cheap, relatively safe (don't eat it kids!), and easy to handle. It stains like a bitch though, and will attack most metals so be careful with spills.
Re:Can also be done in a much simpler... (Score:2)
Anyone tried spark eroding?
Re:Can also be done in a much simpler... (Score:2, Informative)
Something as simple as a magic marker can be used, but it will probably look like ass. A better idea is to use a photo-resist kit. With this you spray the metal surface with a chemical that will protect it from the FeCl_3. The kicker is that light will eat away this protection. So you print your design onto an overhead transparency or something, place that atop the metal, and affix it to a window for a while
Re:Can also be done in a much simpler... (Score:3, Informative)
1) Press-n-peel blue [southcom.com.au], which is a sheet of material that will stick to a surface only where it's printed. It's hard for me to find it where i live, so what i use is...
2) Laser printer and satin ("photo") paper. Laser printer toner is 100% waterproof and melts when heated; you print you design, mirrored, onto a satin paper sheet, then iron it over the metal (previously cleaned and degreased with alcohol), and carefully peel
Re:Can also be done in a much simpler... (Score:2)
No, it eats almost any metal. Maybe not gold, palladium, or platinum, but it has eaten any metal or alloy on which I tried it, including stainless steel.
Easy design masking (Score:3, Informative)
Easily done. Head to Techniks [techniks.com] or some other similar place and get some Press 'n Peel PCB transfer film.
Draw what you want to etch as a negative and then iron it onto your metal. Dip the whole thing in the acid bath and wait a bit. Steel wool to clean off the resist and that should do it.
If you're really cheap, toner is a decent resist. [fullnet.com] No different than making a homebrew PCB.
Re:Easy design masking (Score:2)
Re:Can also be done in a much simpler... (Score:4, Interesting)
I don't see why this wouldn't work on cases. You use an iron to transfer the toner from the paper to the surface to be etched. Extremely narrow traces can be obtained ("MUCH less than 0.01 inches") with this method, so I'm sure it would give good results for case mods.
This website has the detailed instructions:
http://www.fullnet.com/u/tomg/gooteepc.htm [fullnet.com]
Dan East
Re:Can also be done in a much simpler... (Score:2)
Electrochemical reactions happen at extremely low voltages and in this case don't require any fancy reagents. You have the same masking problems with a chemical etch as with an electrochemical etch, but instead of needing a very average DC power supply, now you need something which you really shouldn't allow to touch your skin.
For anyone thinking of using any corrosive to etch metal, look up its MSDS [jtbaker.com] and make sure you know what you're doing. The same can be said of electrochemisty, but we'
Re:Can also be done in a much simpler... (Score:2)
Thing is, when you do electrochemical etching you have two points of "fuckup": the power supply and the etchant itself
Re:Can also be done in a much simpler... (Score:3, Informative)
I have forgotten a lot of chemistry over the years. I thought Ferric Chloride works as an etchant for copper because the chlorine prefers copper to iron so it is happy to trade an iron atom for copper. But why would it trade an iron atom for another iron atom? Now in a solution, there will be free chlorine and iron ions floating about so the chlorine may etch the steel but I
Re:Can also be done in a much simpler... (Score:2)
I've etched brass an copper with it, and seen it leave awful spill marks on aluminum; generally, if it's metal, it will react with it, to different degrees. The reaction is quite slow too, and to stop it you just need to dilute it badly with water. Then the solution
Re:Can also be done in a much simpler... (Score:2)
Because it turns from "ferric" to "ferrous". Ferric chloride is red, ferrous is green. Try this: dissolve enough iron in ferric chloride until the solution turns pale green. Then add caustic soda to it. This will cause the iron to precipitate as iron hidroxide, it's one of the most saturated red colors you can find.
Re:Can also be done in a much simpler... (Score:2)
That's just ordinary acid attack. The method described doesn't need masking and can cut through material. You can cut smooth holes in very hard materials with a slit copper tube as an electrode. If you keep the liquid flowing you get faster cutting (washes away the corrosion products).
Ferric chloride etches copper very well, but for other materials you will want to use other stuff. Around 15 percent nitric acid in alcohol etches steel nicely and quickly
I used to do that with nitric acid (Score:4, Informative)
Bad guide (Score:3, Insightful)
Re:Bad guide (Score:2)
Re:Bad guide (Score:2)
He is releasing cupious amounts of HYDROGEN gas.
Iron plate: Fe
Water: H2O
Salt: NaCl
Methane: CH4 HOW?!?!?! No carbon involved!
This is electrolysis. Splitting water into O- which oxidates the metal (cutting it) and H2 which floats to the surface, gradually filling the room till everything goes Kaboom.
Know what you're doing. Definitely.
Acid? (Score:2)
Re:Acid? (Score:3, Informative)
Resists: You need something that is resistant to the acid, but can be applied neatly, and removed neatly afterwords. It needs to adhere well to the metal surface, yet be resistant to the acid and to water, and any by-product produced. Also, it needs to be resistant to exfoliation - as you start to etch, it's no good if your resist fa
Re:Acid? (Score:2)
see also, battery acid.
HCl ---- hydrochloric acid
see also, component of stomach acid.
I don't know what part of the world the parent
poster is from, but these items are not likely
to be available from any USA "hobby shop" I
have seen. In the USA, either a chemical
supply house or else a friendly local electro-
plating company might be better choices.
However, it should be cautioned that acids
(especially concentrated acids) are quite
dangerous. Protective gear (heavy ne
Tape, knife, and bead-blaster (Score:3, Insightful)
Been doing this for years.
A link dug from the hurlage (Score:2, Informative)
http://gravert.club.fr/galvetch/contfram.htm
Similar to etching pulsejet valves (Score:2)
Slashdot Etched! (Score:2)
Warning, IMisleading Summary (Score:2)
If you look at the pictures, you will notice the edge is not perfect and indeed there are problems with using this method for intricate designs. Especially if you use duct tape as your insulator like this guy did. You could cut your design labor down considerably by us
Salt = Bad (Score:3, Informative)
Use baking soda or sodium hydroxide instead. Either electrolyte will give off substantially less-dangerous byproducts.
p
Who's editing today? (Score:2)
Re:Who's editing today? (Score:2)
Bill Gates Handwriting
Dont you mean "Whos editing today?"
Electrolytic deplating is for pussies. (Score:3, Interesting)
This is easier/more accurate then a dremel how? (Score:2)
This is also pretty labour intensive, you have to completely paint the area you don't want destroyed first, then you can destroy the non-painted area, then you'll probabally have to refinish the edges on anything really complex like a spider design, or text, because in the pictures the cut lines are pretty rag
Which dremel bit to use? (Score:2)
Is there an easier way to do it with a dremel? What part number is best for this?
Re:Which dremel bit to use? (Score:2)
This is news? (Score:2)
Or how about valves for pulsejet engines..
Using it on a PC case? Isnt that pretty much common sence?
Sheesh.. Has the whole world 'gone dumb' or what..
What is next "ooh, look the sun rises. Must be something to get exited about"
Re:Mirrordot Link (Score:2)
Main site + Coral + Mirrordot all failed... Victory !
Re:Mirrordot Link (Score:2)
Not just victory...Fatality...Flawless Victory
Re:how to make your case rust really really fast (Score:2)
Re:how to make your case rust really really fast (Score:2)
Are you sure it's not electrodynamic machining? (Score:4, Interesting)
Items used every day may have under gone this process, turbine fan blades, air bag explosive chambers, hard drive motors (meow), test sabot rounds for tanks.
Are you sure those are all built by electrochemical machining? I suspect some of them are built by its close relative: electrodynamic machining.
Electrochemical machining is reverse electroplating. It pulls metal atoms out, not just from the cut, but from the surrounding metal that is intended to remain, changing its properites.
Electrodynamic machining is a spark to the workpiece through a dilectric solution (typically water or oil). It can cut through anything that can be made to conduct. (You do diamonds by flashing a bit of metal over them for the initial contact. As you're removing diamond, the surface that's left has a microscopic layer that is converted to graphite to keep you going.)
Three sorts of tools:
- Use the end of a wire as a drill. (Feed the wire as the end erodes.)
- Use the side of a wire as a bandsaw. (Feed the wire in the inches-per-minute range so the cutting edge is always smooth and of a known size.)
- Make a graphite electrode in the shape of the hole you want and burn your way in. (Graphite doesn't erode much at all. Replace as needed.)
Cutting action: The spark vaporizes a path through the dilectric and melts a tiny pit in the workpiece. (Polarity is chosen so most of the melting is on the workpiece.) When the spark stops the channel collapses and the shockwave blasts the molten material out of the pit before it can re-harden. Repeat at a rate in the kilohertz range. Spark generally forms at the shortest space, which is where you want to remove the most metal, giving you a mirror finish.
(This effect was originally discovered in Russia about WW II when an engineer tried increasing the life of ignition "points" by putting them in an oil bath to cool them. They disintegrated within hours. It's also why you always use a brush to run current around a lubricated ball- or roller-bearing instead of passing it through the bearing: The effect would destroy the bearing surfaces in a similarly short time.)
The cut-away material ends up as a contaminant in the dilectric. So you pump that through a filter to clean it out.
Motion control is paramount: You sense the spark voltage to tell how far you are from the workpiece and use it for feedback, advancing or backing up to keep your spark path at the correct length.
Contaminants (especially chips) sometimes short the gap, so you back out until you clear it and can spark again. Sometimes you end up machining away the chip. Sometimes you may have to back far - even completely - out of a cut to clear the contaminant from your gap. This may mean retracing your path around several turns. (In the shaped-carbon-rod drill-in mode you also run the rod in little circles and/or back-and-forth it now and then to pump the dirty dilectric out and clean stuff in.)
You're CONSTANTLY backing-and forthing. MOST of your tool motion is back-and-forth, a small fraction is motion into the workpiece as the cut advances. So you MUST use an integer motion-control algorithm that retraces its steps exactly (or within an LSB or so) and doesn't accumulate roundoff err. Any accumulated roundoff, even a TINY bit, quickly walks you out of your path and into the workpiece, shutting you down.
The device is essentially a big power supply, a resistor, a switch, a voltage measurement peripheral, a computer, a motion table, and a dilectric pump/filter. Most of the energy ends up in the resistor. You do it that way as the easy way to control the spark's waveshape. The switch might be a bunch of paralleled FETs on a big heatsink. The resistor might be a bunch of foot-long power resistors, with a fan blowing on them so you can run them far beyond their normal ratings, carefully wired to minimize parasitic inductance.
That's the bulk of the specialized knowlege you'd need to build one, as they were about 15-20 years ago (when I did software for one).
Re:Are you sure it's not electrodynamic machining? (Score:2)
I have done spark erosion (oaky, electrodynamic machining if yer posh). I was doing that on Ni-Ta single crystals which I wanted round for superconducting experiments, so I had the equivalent of a
Re:Are you sure it's not electrodynamic machining? (Score:2)