eSCHEn
Bit Wrangler
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I've had varying degrees of success with FeCl3 and transfers. I work on copper PCBs, chunks of copper and cast aluminium enclosures (geetar pedals).
Here's what I've learned:
Source Image
First you need to make your sketch on the computer. Use whatever program you like. You can transfer this image in two ways. One is the cheap-ass way at home and the other is to get someone to do the leg work for you.
Home Method
Printed Method
Etching
Both methods now fall here.
Material
I've used 1oz and 2oz PCBs, 5mm thick copper, 2mm thick aluminium and loads of other random stuff. I'd say a sheet of copper or brass would be my first material to try Pete but as long as it's "soft" so the acid eats it quickly enough then you should get success.
I believe @cardiffrob used a similar method to do the etching on his Alta head.
Here's what I've learned:
Source Image
First you need to make your sketch on the computer. Use whatever program you like. You can transfer this image in two ways. One is the cheap-ass way at home and the other is to get someone to do the leg work for you.
Home Method
- You want to print your image using a laser printer onto either a) posh transfer paper like "press-n-peel" b) cheap transfer paper from China or c) glossy photo paper. When you print you should increase the toner density to max and reduce the fuser temperature. If you can't do it directly then you fudge it using the wrong type of paper to get the same result.
- Iron on the transfer with very heavy pressure and roughly 175°C temperature at the job face. Takes a while (several minutes) but is required. Alternatively you can use a laminator and pass it through that several times. For the aluminium enclosures I have a jig consisting of two plates of 6mm steel and some M6 bolts to tighten them together. This then gets shoved into a domestic oven for ten mins at temperature.
- One the item is cooked then cool it down under a running tap. Don't let it cool slowly as it'll re-adhere to the paper more.
- Now, under a slowly running tap you carefully rub away the backing paper until you're left with just the toner. If you've done it right then the toner will be quite firmly attached and you will be able to rub it with a sponge without it coming off.
- Be prepared to do this operation several times until you get your heat and timings correct. Bit of a palaver but you can get some nice results.
Printed Method
- Take your image and give it to a friendly vinyl printer. Get them to cut it out.
- Weed the print if it isn't. Wherever there are gaps will end up being eaten by the acid.
- Stick the print to the job.
Etching
Both methods now fall here.
- Make up a saturated solution of FeCl3. Warm is better but don't get it hot.
- You now need to apply the solution to the transfered job. You will need to keep reapplying or set up a trickle from a cheap pond pump. If you don't replenish regularly what happens is the acid eats into the metal but then gets stuck there with a lower concentration from it having done the etch. You need to replace this with fresh acid to keep the consumption rate up. That's what the bubble chambers etc do in a more professional etching scenario.
- Time-wise you will have to play it by ear.
- I've found doing this gently with lower concentrations produces a worse result as the acid eats under the mask edges and blurs the detail. Warm and saturated FeCl3 has always given me my best results.
Material
I've used 1oz and 2oz PCBs, 5mm thick copper, 2mm thick aluminium and loads of other random stuff. I'd say a sheet of copper or brass would be my first material to try Pete but as long as it's "soft" so the acid eats it quickly enough then you should get success.
I believe @cardiffrob used a similar method to do the etching on his Alta head.
I can shallow engrave a plate leaving the letters high, takes a while though.
