Thread: Etched or Engraved?

I got the idea from seeing copper etched and it worked fairly well. I coated a knife in finger nail polish and etched a knife and figured I would try a razor. Instead of nail polish I used one of those huge sharpies and scribed a pattern. The first one I let it sit in the solution to long and it started to eat away the metal underneath the ink. The second time I let it sit for a few min then I rinsed it off and let it sit for another few min. The etch was as deep as most of the etches that I have seen, but not as deep as the ones like the one posted here. I tried using a rubber stamp with a design, but the curve of the razor wouldn't let me adhere the ink smoothly. I am still working on trying to get the stamp to not slide. Scribing works well, but I am not all the confident in my artistic abilities for this. Here is the one I experimented with scribing. You can tell which one I let sit in the solution to long. I have been wanting to try it with some electricity. Still a work in progress.

I would suggest using a proper resist (wax, straw hat varnish, etchers hard ground, etc - if in doubt, find an intaglio printmakers supplies and ask them) and either electric and/or acid. With a thicker, more resistant coating, you reduce the risk of biting under the edges and actually foul-biting the surface of the plate, something which thin marker pens are prone to.

Ferric chloride actually produces hydrochloric acid when mixed, so is suitable for steel. Even with acid/electrolysis, you have the problem of 'underbiting' the edges of the design.
Copper sulphate can be used for steel too, but salt in equal proportions is usually added to stop the plate being coated in copper.

The blotchy/indistinct/grainy appearance is usually caused by the dissolved detritus falling back onto the metal - you need to agitate enough or use something like a birds feather to keep brushing away the detritus and the bubbles that form.

Another way to produce a deep etch in the fraction of the time is to get a cheap aquarium pump and some plastic tubing and use this to direct the etchant - sometimes the results are startling, measured in minutes compared to hours.

The rubber stamps worked particularly well - but of course, they had the foresight to reproduce the pattern on a stamp with a curved surface that suited the hollow of the blade - using a flat stamp will only result in smearing and distortion when pressed into the hollow of the blade.

You can buy (or make your own) photo-resist, and print your design onto acetate with an inkjet printer (special surface acetate to hold the ink) or use regular laser photo paper and a laser printer. You then soak the print and pull off the clear film from the white paper, then gently work the back to get rid of all the paper fibres. Both produce what you will use as a negative. Suitably cut to size, you an tape them to follow the curve of the blade hollow. However, for this method you need a UV light source - a face-tanning unit is suitable, or you can buy the correct bulb in a reflector.

Regards,
Neil

Wonder if this is where the Mad Hatter came from?

Originally Posted by Neil Miller

Definitely not stamped, but acid etched.

I have seen the rubber dies used to coat the blade with the resist in some book or other - they look like a regular old-school printing stamp and were dipped in liquid resist (either wax or a gum - usually 'gum arabic' - to which a light-sensitive hardener like potassium dichromate is added) then stamped on the scrupulously clean blade.

Exposure to a strong UV light source - or even the sun - hardened the gum resist. Unfortunately the pot. di. also gave off carcinogenic vapours, despite being in use regularly when I was at college in the late 1970s and used for silk-screen printing and hardening felt in hat making. Seems like the poor old hat-makers either got it from mercury or pot di inhalation!

Photographic processes were also used, having the benefit of the whole blade being dipped in the resist, a negative applied, exposure to strong UV light which hardened the resist not covered by the dark areas of the negative, then washing off the soft areas and dipping in acid.

In the other process, once the rubber stamping had dried a resist was applied to the rest of the blade by hand - usually a bitumen-based printers resist.

Regards,
Neil

Originally Posted by WW243

Wonder if this is where the Mad Hatter came from?

It certainly is. The phrase is inextricably linked with the Alice Through The Looking Glass character by Lewis Carroll (1832-98)but he only popularised the term - the condition was well-known before his time. It is associated with hat-making because mercury was used in the process of matting and hardening animal fur (felt) used for fine hats. This use of felt goes back to around the 18th century when camel urine was used for this purpose, as it was rich in urea. Syphilis and other genital diseases were also popular at this period of time and mercury was used to treat the symptoms. Some hat-makers used their own urine in preference to camel urine, and it was noticed that those who had taken mercury cures produced better hats, so eventually mercury itself was used. The vapours of mercury impart tremors, irritability, shyness, inability to work under command or to command others, loss of hair, fingernails, teeth etc. The latter symptoms probably increased the individuals desire to remain closeted up, and as hat-making was often a lonely, solitary existence the madness became associated with hatters.

However, it is/was an occupational disease, and affected all those who work with and are subject to the vapours of mercury. Of particular interest to us should be the blade forgers who used hot mercury to temper steel. When Louis Daguerre invented the Daguerreotype (late 1830s), one of the earliest forms of photography, a silver-coated copper plate held an image that was developed using hot mercury fumes.

In gilding - swords, knives, armour, etc, a gold amalgam was often used - gold can be dissolved in mercury, painted on metal or otherwise applied, then the mercury is driven off by heat, resulting in exposure to its vapours. This is a very old form of mercury poisoning.

Regards,
Neil

On a side note, the photographic process you mentioned is used a lot these days to counterfeit Nazi markings on the "lesser" blades that were unmarked at issue or to make an outright forgery look real. Apparently there are some masters of the craft out there as more than one knowledgeable collector has been fooled.

I've never been a fan of Nazi stuff, but I see a lot of it my travels and hear stories of woe from those that collect. I've looked at both closely and I couldn't tell the real from the fake.

Done correctly, the process can give incredible detail.