Thursday, May 28, 2009

On inking

I said I'd tell you about inking earlier, so here it is. This is basically a description with the different inking methods I've tried.

The application method for methods 1, 2 and 4 are essentially the same. You apply some of the ink (or paint), make sure it's in all the etched lines, then squeegee ink off the top with a scrap of copper that has a straight edge. Once you've done this, let the ink/paint set for however long it needs, then rub it down with steel wool until you're left with ink in the etched lines, and nowhere else. Cover with a protective lacquer if you want.

Method 1: Lithographic/etching ink. About $20 a tube from Eckersley's. This is an oil base soft ground used for etching hand drawn images. Because it was what I had available, this was the first ink I tried. While it sticks in the etching reasonably well, it takes days to dry, and the lacquer that I was using at the time dissolves it. It's also really messy. I was finding black oily stains for weeks afterwards.

Method 2: Because of the waiting time involved with the Lithographic ink, I decided to try with black spray paint. Simply spray onto your plate after etching, squeegee the excess off, and allow to dry. I found that while this was quick, the lacquer, once again, dissolved the paint. It's a lot cleaner though.

Method 3: Permanent marker. Basically, colour the etched lines in with a thick black marker, the ones made by Staedtler are the best. The problem with this method, is purely the recurring lacquer problem. This is a very easy method.

Method 4: This is the best one of all. It's the same as method 1, but use black acrylic paint instead of lithographic ink. This paint dries really quickly, after squeegeeing it takes about 15 minutes. It's cheap, about $3 a tube, and it's lacquer resistant because it's water based.

Thursday, May 21, 2009

Brass etching

In a fit of procrastination this evening, I decided that I would do a brass etching with the brass that appeared in the mail yesterday. I went with the airship pilot's badge from earlier. The transfer was really good, the magazine peeled off in one piece, which was a really good feeling. Here's a picture of the magazine page after peeling, with the brass next to it:

I put it into the tank with my new plate holder (left, lovingly turned down on a school lathe), and switched the power supply on, it drew between 1.5 and 2.5 Amps the entire time, and built crud up on the surface a lot faster than the copper did. Some copper also rose to the surface of the brass. There was no surface pitting either. This etch took about 15 minutes.

In case you're unfamiliar with the difference between copper and brass, brass has zinc as well as copper, and looks gold rather than red. The brass is at the top, and copper at the bottom:

Here is the finished etching, after being 'inked'. More on inking later.

Wednesday, May 20, 2009

A plan for the future

I was talking with a friend of mine recently, and discovered that her father is a lithographer, and, as such, does copper etchings. She said that he did acid etches, which piqued my interest, so I have done a little research, and come up with this. It's called the 'Edinburgh Etch', and uses Ferric Chloride as the 'acid'. I say 'acid' because it is actually a salt, not an acid. Anyway, I shudder to say it, but...Dick Smith...sell bottles of Ferric Chloride, so I shall purchase some, and start tinkering.

On a different note, a package came from A&E Metal today, containing a sheet of 1mm brass, and a sheet of 0.5mm nickel silver (which actually contains no silver), and some brooch backs. I intend to try and electroplate the nickel silver onto brass and copper. But we shall see.

Wednesday, May 13, 2009

An experiment in separation

I have found that when I etch, the plate that I'm etching heats up to a point where the toner flakes off the plate, leaving the copper underneath exposed. This evening, I decided to try and change this. in the past, I have put the two plates very close to each other, about a centimetre apart. While this positioning means that it only takes about twenty minutes to etch a plate, I think it contributes to the heat.

Anyway, I transferred this picture onto a piece of copper, and put it into the etching tank. The picture was from the front cover of the first issue of this magazine.
But this time, instead of putting the two plate really close together, I put them on opposite sides of the tank. Because the resistance would be much higher, I knew I would have to leave it for a lot longer than normal. I put it on at 15 volts, and between 1 and 1.25 amps, and came back 50 minutes later to check it and turn it off, as I was leaving the house to ferry lurkers around town.

When I got home again, I turned it back on again, and got to tinkering around the workshop. Another 50 odd minutes later, I turned it off, this time for good. Not as much toner had fallen off as in previous attempts. Success! I got a nice gradation of depths, deeper in the wider lines, shallower in the narrower. Then I cleaned it off, and inked it. Here's what it looks like.

One thing that I have noticed with using magazine pages for toner transfer, is that parts of the image from the magazine sometimes transfer too.You can see this above and to the left of the bird. So sometimes, my etchings end up with words etched into the background and other things like that. At some point, I will attempt a different paper.

A Glossary

It has been brought to my attention that some of the terms within the pages of my blog are not clearly defined. This is where I will endeavour to define them for you. If you find anything you are unsure of, please either email me, or post a comment with your request underneath this entry. Thanking you, and I hope I can clarify anything that is unclear.

DC- Direct Current. The current flows only one way.
LDR- Light Dependent Resistor. A resistor whose resistance changes depending on the amount of light falling on the surface.
PCB- Printed Circuit Board. A sheet of fibre glass with copper traces stuck to the surface. The copper traces are the connections between all the components.

Collection of numbers and letters: Component identification code (usually arbitrary, sometimes following a pattern). eg. LM7805, LM7812. LM has no meaning to me, 78 denotes a 1 Amp limit, the last number, '05', '12' denotes the voltage output.

Voltage regulator: Takes a DC voltage in at one end, and outputs a regulated voltage at the other, as well as a limited current.
Transistor: These switch, and amplify. Information about their markings can be found here, and further information here.

Wednesday, May 6, 2009

An experiment in stainless steel and blue paper

On the weekend I split a packet of Press'n'peel Blue with a mate of mine, because we both wanted to try it out, having only ever used magazine pages. I also bought some stainless steel wall-plates, used for light switches and audio systems etc. For a couple of days I tried to find something that would look good on a stainless steel wall-plate as a replacement for my boring white plastic light switch. I finally stumbled upon the back of a card. After mucking around with it in Gimp for a while, I finally got it scaled to the right size for my wall-plate. I decided then that this would be the perfect opportunity to test out the Press'n'peel Blue. Accordingly, I printed my image onto a sheet of it, and proceeded to align and iron it. FAIL.The bottom picture is my first attempt at the Press'n'Peel, and the top is the second attempt.
My iron was on too high a temperature, it was still on the setting I use for magazine pages. I turned it down to 'Synthetic' and tried again. FAIL. I don't know if it was poor technique, or if P'n'P doesn't work on stainless steel, or if it even works at all, but only about a third of the image adhered to the metal, the bits that I've drawn around were the only bits that adhered. So I went back to magazine pages, and, wha'd'you know, it worked. It wasn't perfect, but about eighty-five percent of the picture was there.

I took it out to the workshop and set up a brand new tank, this time with table salt as the electrolyte. After discovering that yet another fuse was blown in my power supply, I switched to batteries. My smaller battery was too small to have much of an effect, and when I put my bigger one on and tried to measure the current the tank was drawing, the jumper leads exploded. So I hooked it back up, but with three pairs of jumpers instead of one. Much better, and it was pulling about six amps.

After blowing up lots of little hydrogen bubbles, I took it inside and cleaned it off. It's pitted in places, and looks very raw, but it has a certain
je ne sais quoi to it, appealingly aged.Here it is installed on my wall, I put some Prussian blue oil paint over it to bring out some of the detail, but the camera doesn't show it.

Monday, May 4, 2009

Intaglio plate

This evening I decided to try and make a printing plate of the airship wings image. Because I wanted the final image, in this case the print, not the plate, to be a positive, I had to reverse a step.

When I printed out the image on the magazine page, it was a positive. This means that the blank spaces (which are supposed to be white) would be etched out, leaving a negative, once you put the ink on and press it into some paper, it becomes a positive image on the page.

I bought some ink in a bottle today with this in mind, as well as a roller. Both came from the art shop in Dickson. The roller is made of plastic, so somehow I had to protect it from the heat that remains in the copper plate during ironing. I found that I had a roll of aluminium tape in my workshop, so I put a couple of strips on the roller, et viola! A protected roller. After heating the toner, I rolled the copper and the paper with the roller, and then soaked the paper off. I was pleased to find that the roller helped in the quality of the transfer, more stuck down than usual. There were a couple of little spots that came off while I was removing the paper, but they were in non-critical spots so I didn't re-do it.

Unfortunately, while I was drilling the two holes in it, my drill slipped and I bent the plate. I straightened it out again, but I think I may have weakened the toner's grip on the copper.

I hooked the plate up to the new and improved power supply that I did yesterday (which works wonderfully, I might add), and etched for about twenty minutes, after which the toner had started falling off. I suspect this was because the plate was getting quite warm, softening the toner up, and also because of the bending I mentioned.

In spite of this it turned out reasonably well, and I cleaned it off, painted a thin layer of ink on to it, put some paper on it, and went over it with the roller a couple of times.

I think next time I need to etch deeper, and not bend the plate.

I once again apologise for the photos. The lines (particularly in attempts 1 and 4 are actually quite sharp.

Friday, May 1, 2009

Power supplies

I am very fortunate. I have a friend who works for Questacon, who has lots of fantastic electronic junk. One prime example of this is a trio of variable linear power supplies, each having a range of 9-18 volts DC. In my annoyance at having to recharge my SLA batteries after etching, I finally broke one of the power supplies out in the place of the battery. It's a wonderfully simple device, you just put mains in one end, and a preset and adjustable voltage comes out the other end. Because I had no proper electronics enclosure on hand, and lacked the motivation to build a nice box to put it in, I had decided to mount it in an abandoned lunchbox. This was necessary, because otherwise there would have been bare, live mains wires sitting on top of my workbench, which is both permanently covered in crap, conductive and non-conductive alike, and is within easy reach of my two lurkers. I wouldn't want to zap them, now, would I? Anyway, I set the voltage to about 10VDC, zip tied it in, put a switch and some connectors and a fan for ventilation in as well, and closed the lid. That was my power supply until today, when I mounted it up in a nice box, with adjustment knobs for voltage and the current limiter, and all the connectors. Still to come is an ammeter and a polarity switcher, which will allow me to plate with this supply.

You, however, may not be as fortunate in your friends as I am. Never fear. All is not lost. You can use other power supplies. As I mentioned before, SLA (Sealed Lead Acid) batteries work very well. They're basically car batteries, but they don't spill, and you can get them in different strengths. You will, however, also need to shell out for a charger, and keep the battery charged. What a pain. But, that's not the only alternative. Do you have a phone that's broken? (A land line, hands free phone that is.) Or a broken scanner? How about some dead computer speakers? Most of these devices are powered from a 'plug pack', a step down transformer that plugs straight into the wall. One of these plug packs will suffice as a power supply for etching. Just make sure the output is DC, and at least three volts. You may want to solder some alligator clips onto the end of the wires (after lopping the plug off), to help you identify +VE and -VE, and to make your connections easier.Pictured above are a 7 Amp/Hour SLA battery and some plug packs