Saturday, July 18, 2020

Second attempt at salt etching

Curses! I thought I might have been getting a decent result. But, I'm getting ahead of myself.

Current biggest issue is getting a decent resistor onto the aluminium with enough detail that I can get crisp lettering. I think at the moment the issue is that the printer that I have is either low on toner, does not deposit enough toner or is set up to maximise toner and I can't turn it off.

So the first thing I tried was the first method (glossy magazine paper) with a bit of nail polish remover. I also added pressure by using a clamp I picked up from the hardware store. However, I feel that my mistake on this attempt was that I used two bits of metal (the aluminium stock and bit of scrap steel) and it didn't put equal pressure across the toner.

Result: toner didn't stick.

(Also, didn't clean up the metal first either, which can't have helped.)

Second attempt today was using the second method (back of sticker paper - waxy type). This is the one that is supposed to give the best results. The immediate issue was that the toner didn't stick to it going through the printer. Not what I was expecting, I poked around the settings a bit and managed to get a bit of toner onto the paper. The result was … lacklustre.

So I went back to the first method, but this time I put some padding paper between the paper carrying the toner and the steel sheet, and this time I managed to (finally!) get a decent amount of toner onto the aluminium. Yes!

So hooked it all up, got the juice flowing and the result was … about the same as the first time.

It's definitely an issue with the toner. It isn't on there thick enough to stop the salt water from eating away at the aluminium, which leaves it with that chewed out look and rough lettering. I can't think of any other way to get the amount of detail on there that I am after other than printing it. I was looking at the photoresist film, which could work. But that would require buying the film, plus some UV light(s) and who knows how much more equipment. I know we need to buy more toner for our printer, but there should be plenty of black.

I think for the next effort, I'm going to have to try a heat option. Which will either mean investing in a hot air gun or using the oven. Toner should need about 100c to melt the toner, the trick is to not burn it. More experimentation needed!

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