Gerv Wright explains :
HOW TO ETCH YOUR OWN BRASS NAME & WORKS PLATES
I started etching my own plates having become quite a bit dissatisfied with both the availability and fidelity to the original of commercial plates. The later aspect being generally due to the use of commonly available fonts which in some cases were poor imitations of the original lettering.
There is any amount of information on the internet and particularly on YouTube about chemical etching. A lot of these relate to transferring circuit designs to PCBs (Printed Circuit Boards) by electronics enthusiasts but the method is the same. I’ve chosen to use the toner transfer method of putting an image onto a brass strip and then etching in Ferric Chloride. As we are transferring toner it is necessary to use a laser printer. The alternative of using photo sensitive resist seemed relatively complicated and uses more chemicals.
Within this basic method there a numerous different techniques several of which I have tried so I’m going to outline my experiences.
DESIGN
Firstly, we need to design our artwork. I start with a photo, ideally square on but if it is at a slight angle I straighten it with photo editing software (in my case Affinity, but no doubt others like Photoshop will do the job). I have quite a number of photos of my own, including a selection of works plates on the wall at Statfold, but if I don’t have anything suitable I search the internet or take from a book. I initially, continued using Affinity to create the name/works plate on a separate layer over the top of the photo. This creates a pixel-based drawing and is quite a laborious process even though you can do multiple pixels at a time.
I’ve now graduated onto using a free vector-based drawing software called Inkscape. I drop a photo into the software, scale it and then trace the outline of the letters etc. The outline is easily adjustable, so I tend to draw any curves as a chord, i.e. straight line, and then pull them to shape afterwards.
The screenshot shows a couple of letters traced onto a photo of a nameplate that I’ve converted to black and white. For the trace I use a colour with a level of transparency to enable me to both see the line and see through it. One of the curves on the R is yet to be pulled to shape. When complete the letters are filled in and the areas requiring resist turned black and those to be etched left clear.
PRINTING
Originally, I took my Affinity artwork into Microsoft Publisher to scale and print it. With Inkscape you can print direct. However, in both cases the results were disappointing with obvious pixels spoiling the straight edges. The print engines on both are not good enough to print the detail in our small plates. The solution is to save/export a PDF version of the artwork to at least 300dpi and print from there.
There are a variety of mediums that can be used to print on to. Amongst others I’ve seen are acetate, glossy magazine paper and specialist papers. I’ve tried the glossy magazine paper and cheap yellow toner transfer paper obtained from eBay and both do the job. However, the final etch shows signs of the etchant leaching through the toner and leaving the raised surface with tiny pockmarks. I now use expensive blue Press-n-Peel PCB transfer film (from fortex.co.uk) but cut each sheet into halves to make it more economic. As well as transferring the toner a layer of the film is also transferred making a much better resist. I print more than I need to allow for a few fails.
The photo shows a various plates printed on the Pres-n-Peel - note they need to be printed in reverse.
TRANSFER
Again, on YouTube there are multiple ways in which this can be achieved. The most common appears to be using a domestic iron, hotplates also used quite frequently. I’ve tried ironing but I couldn’t get this method to work for me. What I find works though is using a laminator and I think the key here is that the laminator provides both heat and pressure.
Firstly, we need to cut a strip of brass and clean it. I rub it down with a fresh piece of 800 grit abrasive and clean with acetone and repeat this procedure at least two more times. The press-n-peel is taped (Sellotape or parcel tape) to the brass taking care not to cover any of the artwork. Before doing this make sure the acetone has dried from the brass or the toner will smudge - don’t ask me how I know this! The plate is then placed inside a sleeve cut from a paper envelope and passed through the laminator. I initially passed the plate 8 times through the laminator turning the plate over each time because that’s what I’d seen on YouTube. I’ve since reduced the number of passes to 6 which works and takes less time.
The plate is allowed to cool before peeling off the press-n-peel. Taking care to thoroughly clean the plate pays dividends and I estimate my success rate as in the region of 80%. Occasionally, there are minor blemishes which can be corrected using a fine permanent marker. If the transfer hasn’t taken well though, the brass is cleaned off with acetone and reused.
The photos show the envelopes feeding through the laminator and the result with both the toner and Press-n-Peel adhering to the brass.
ETCHING
As with everything else in this process there is more than one way to etch. Ferric Chloride is a popular etchant, it doesn’t give off any toxic fumes and etches accurately. The solution can be reused many times but will eventually lose its strength. Handled with some care it is relatively safe. Ferric Chloride does have its disadvantages and for a start it will stain anything it touches. From a process point of view, it doesn’t clear the sediment that builds up which potentially prevents further etching. Etching also takes time.
The ferric chloride is put in a suitable container and for our purposes the end of a 4-pint milk carton is perfect. The sediment issue is dealt with by suspending the plates upside down from a polystyrene float and providing some form of vibration to keep the acid moving. Commonly recommended is using a fish tank pump to provide a stream of air through the etchant. I however used an old foot spa which apparently was too useful to be thrown out, but which hasn’t been used for its designed purpose for at least 20 years. The well of the foot spa enabled me to put the milk carton and contents into a reservoir of warm water and with the vibration setting on the contents are moved nicely.
Further refinement came when I discovered something called the Edinburgh Etch on the internet. So named because the inventor Freidhard Kiebeben was an artist and researcher at The Edinburgh Printmakers Workshop. By mixing citric acid with the Ferric Chloride the sediment is dissolved as it forms, meaning that suspending the plates upside down and vibrating the mordant is no longer necessary. The recipe for Edinburgh Etch can be easily found online.
I keep the Edinburgh etch in a coffee jar - the brand we use has a glass stopper which seems eminently more sensible than using a jar with a metal lid. I now no long need to transfer the etchant from storage container to etching bath and back. A lot less faff and the virtual eradication in the number of mysterious yellow stains! The Edinburgh Etch is also said to speed up the bite of the Ferric Chloride but I can’t say I’ve noticed the difference. The brass plates are taped on their reverse side with the tape being long enough to form a handle to grab with tweezers. They are then dropped into the jar which I put into a bowl of hot water.
When etching is complete, and I usually etch for 45 to 60 minutes, the plates are removed and rinsed by dropping in the water in the surrounding bowl. The resist is removed with acetone leaving a nicely etched plate. The photo shows several plates mostly as etched but a few with a temporary coat of paint.
To finish the plates they need cropping and filing round the edges, the indent filling with paint and when dry a rub down with very fine abrasive.
January 2024