Etching Brass on the Cheap

[MJI]

So which side of paper was used, and what printer - looks very interesting

[ianmaccormac]

That looks an excellent result. As MJI has asked, what paper etc!

Cheers

Ian

[RedgateModels]

I did a test this afternoon, not ironed it yet, but if you take a sheet of sticky labels, remove all the labels and the spare paper around the edges so you are just left with the backing paper, then print with a laser printer onto the same side that the labels were stuck to you seem to get a nice smooth black print onto the waxy layer. I guess this should transfer well to the metal. .....

Edited April 12, 2012 by RedgateModels

[MJI]

I did a test this afternoon, not ironed it yet, but if you take a sheet of sticky labels, remove all the labels and the spare paper around the edges so you are just left with the backing paper, then print with a laser printer onto the same side that the labels were stuck to you seem to get a nice smooth black print onto the waxy layer. I guess this should transfer well to the metal. .....

 

Hmm laser printer at work and I will grab some backing sheets from a supplier

[CWJ]

I did a test this afternoon, not ironed it yet, but if you take a sheet of sticky labels, remove all the labels and the spare paper around the edges so you are just left with the backing paper, then print with a laser printer onto the same side that the labels were stuck to you seem to get a nice smooth black print onto the waxy layer. I guess this should transfer well to the metal. .....

 

What he said!

 

Thanks for all your comments, unfortunately RMWeb crashed during my last post and I lost the enthusiasm to write it out again, hence the lack of detail! The paper I used was from an A4 sheet of sticky paper labels made by 'niceday', but I imagine any paper with the same waxy finish would work. Others on internet forums have used pages from glossy magazines with good effect.

 

The printer was one of the huge types used by offices, not that I would dream of using company resoures for my personal hobbies, you understand... Seriously, the important thing is that it's a laser printer. Inkjet printing would just smudge, and wouldn't transfer to the brass.

 

Redgate, if you get time to report back on your progress I'd be interested to hear how you get on! Remember to read the Nigel Lawton website and follow his advice.

 

One more tip from me - after ironing, let the toner cool completely before attempting to peel back the paper. If, when you start to peel the paper away, some of the toner is still stuck to the paper, iron it again. But beware, if you iron for too long, or press down too hard, the toner will be smudged.

 

Cheers,

 

Will

[RedgateModels]

OK, bit of progress. Not done any actual etching yet but here's some MERG PCB artwork transferred to copperclad ready for the first two DC06 PCBs

 

 

Went really well, a couple of gaps where the toner did not stick where the labels were cut from the sheet, easily fixed with a permanent pen, also one of the mounting hole circles lifted, again no biggie.

 

I'm going to print another copy today and get that onto the pcb before starting to etch.

 

For info, printed using a Xerox 6110 laser printer onto sticky label backing sheet (waxy side) printer set to "best", transparency and black and white

 

Looks good so far though

[CWJ]

An excellent pattern there, Redgate. My toner never transferred as completely as yours has, so you must be more talented with the iron!

 

On one hand it's very depressing that your first attempt is better than all of mine put together (!), but on the other hand I can console myself with the dubious logic that my fumblings may have led to you setting off on the right foot...

 

Congratulations on the Model Rail article, by the way, an excellent read.

 

Cheers,

 

Will

[RedgateModels]

All the toner transferred doing another tonight whilst SWMBO is out - don't want her to get ideas with me and an iron in my hand

 

Stop it about the MR article, not seen it yet, tomorrow beckons though .......

[Nelson Jackson]

I'm sorry for replying to such an old thread, but the original post and following instalments were incredibly interesting, I never knew something like this could be done.

[Robin2]

As this was resurrected a few months ago I thought it would be useful to mention my recent success at electro-etching some 10 thou brass sheet using salt water for the electrolyte.

 

I have been put off from trying etching by the problems of using, storing  and disposing of ferric-chloride safely in a small space. I have also been wary of the problems mentioned here about getting the toner to adhere to the brass and the inconvenience and expense if it does not, or if the design proves inadequate.

 

A few months ago I bought a Silhouette Portrait CNC cutter which can cut designs into sticky-backed vinyl (Fablon used to be a brand name). The vinyl can then be stuck to the brass to create the mask. Obviously you need a mirror-image vinyl mask for the back of the brass - just as with the laser printer process.

 

I don't expect it would be possible to create a vinyl mask with really fine detail parts - the laser printer would probably be better (assuming the user can get it to work) and the use of a photo-sensitive mask is probably needed for the finest detail.

 

I got the idea for electro-etching on the web by accident. This Instructables article is one of the things I found. I soldered a wire to the brass sheet and connected that to the + side of a 12v battery and for the negative electrode I just striped the insulation from about 3 inches at the end of a piece of multi-strand copper wire. I made the electrolyte by dissolving as much table salt as possible in the water. The etching took about 1 hour and the current was less that 0.5 amps.

 

This is an image of my first attempt - making 00 gauge coupling rods. The discoloured parts are because I forgot to de-grease the brass before sticking the vinyl to it.

 

 

Have fun. Save money.

 

...R

[Robin2]

I was sent a PM by someone who has had problems getting Fablon to stick to the brass and I figured it would make more sense to make the answer generally available.

I have only done a few etches and the stuff I have is not Fablon - it has Alkor Venilia written on it (never even noticed the name until now.

I have just washed the brass with wash-up liquid and dried it with a kitchen towel. For my most recent successful test of an etched chassis I "painted" the clean brass with water with a little wash-up liquid in it and that allowed me to slide the vinyl around to position it carefully. I then squeezed out the excess water and dried it with another kitchen towel followed by carefully pressing it with a sheet of paper over it to avoid moving the vinyl. I then left it for about an hour before starting the etching.

 

I had seen this "sliding around" trick used by someone making nameplates at some of the model railway exhibitions.

 

...R

[alfsboy]

I used Letraset  straight onto brass to make name plates and grills for cars  and a few other bits . Humbrol Paint also worked well .

[Robin2]

I have been experimenting further with the possibilities that the Silhouette Portrait offers for electro-etching. I mentioned in Reply #35 that it would be difficult to create a mask with very small cut-outs using vinyl.

Then I came across this YouTube video

which creates an etch mask by painting over the surface and then scribing away the paint for the lines that need to be exposed for etching.

I quickly found that permanent markers are not adequate to protect the brass. The best protection seems to be with nail varnish but it does not scribe well. My latest test (see pictures) was done using Humbrol enamel matt black paint. I doubt if the colour matters. In early tests the enamel seemed to protect the brass as well as the nail varnish but it took about 2 hours to etch the parts shown and by that time the enamel was failing to provide enough protection. Nevertheless I think this technique offers a lot of promise. Maybe gloss enamel would be better, or maybe I can figure how to scribe nail varnish.

I made a scriber-holder for my Silhouette Portrait from a piece of aluminium I happened to have. The scriber itself is just a piece of 2mm silver steel with a point filed onto it. I have not hardened it.

The next two pictures show the two sides of the brass after scribing.

To position the brass in the Silhouette Portrait I printed a piece of card with registration marks and then used the Portrait to cut a large rectangle from the centre to create a frame. I glued the frame to a larger piece of card to make a backing sheet. Then I can accurately locate the brass by pushing it into the corner of the frame and holding it with a couple of bits of masking tape.

The 4th picture shows the rather messy aftermath resulting from 2 hours of etching. The smaller piece shows the nice shiny brass surface that was fully protected by nail varnish (right hand side) and Humbrol enamel (Lhs) in an earlier test where the etch time was shorter.

And the 5th picture shows the parts after a bit of cleaning up.

The window-frame has come out well.
The next item is an attempt to create something equivalent to a radiator grill by drawing a series of diamonds hoping the centres would all fall out. Some did, some didn't. I think another technique will be required.
Then I tried to make something like a drain cover with etched grooves on one side only. That seems to have worked reasonably well.
Some of the spokes in the wheel have disappeared altogether - I may have drawn them too thin to start with.

 

...R

Edited August 8, 2017 by Robin2

[Robin2]

After a lot of fruitless experimenting with different substances for etch resist (Humbrol matt black paint and Boots "Collection Lasting Gel" nail varnish seemed best) I eventually read the "instructions" again which say that a high voltage can cause the resist to fail. So I tried etching powered by a pair of AA alkaline cells (about 3v) and it sorted out all the problems.

 

I got a nice clean window frame after about 75 minutes using black permanent marker as the etch resist. The marker has the advantage that it is easy to remove from delicate parts.

 

The nail varnish is also easy to remove but it does not scribe as easily. The Humbrol paint scribes well but is hard to remove with white spirit.

 

Edit to add ...

I am having second thoughts about using salt-water for the electrolyte as more reading suggests that it produces some chlorine compounds.  I have also been trying copper sulphate solution as the electrolyte but the permanent marker does not work as etch resist.  More experiments ...

 

...R

Edited August 20, 2017 by Robin2

[CWJ]

Well a few years have passed and I find myself in need of etched parts again.  It has been interesting to revisit this topic and catch up with Robin2's progress using his CNC cutter to create etching masks and the electrolytic method using salt.  I've reinstated the missing photos in the preceding thread for the enlightenment of anyone wanting to avoid the many mistakes I made!

 

As before, my mission is to etch some parts of mediocre quality but still better than what I could make by hand, using only household items. 

 

Spoiler alert: this is unlikely to give better results than the previous project described above.

 

The difference is that I need some quite small and finely-detailed parts this time so I may ultimately find it necessary to have them professionally etched instead, which is what a more sensible person would have done in the first place but I quite like the satisfaction of making things for myself if possible.

 

The plan of attack is roughly:

1. Draw out etched frets using ordinary MS Office drawing tools that anyone can use (I will learn to use CAD one day, but I want to make these parts faster than it would take me to do so).
2. Use the toner transfer method to mask the brass sheet (the details are too fine for Robin2's much more appealing vinyl cutter method, even if I had one).
3. Either etch in the ferric chloride I already have (it's been sitting in the same plastic tub for 10 years, so I either need to use it or find some way to dispose of the stuff!) or try Robin2's salt water technique.

Wish me luck...

 

Cheers,

 

Will

[CWJ]

OK, here's Step 1.

 

Here's an example of the artwork, which I draw at a scale of 2:1 to make the fine details easier.  This happens to be a cab floor and bulkhead wall for a Blackpool Tram.  I follow what seems to be a common convention of red for areas etched on the front of the brass and blue is etched on the back.  White is etched all the way through.  

 

 

In this example, the red panels are etched on the front as they'll be visible through the windscreen.  The door isn't supposed to open, its sides are only etched through so that the outline of the door can be seen from both sides.  The etched line isn't as wide as it should be for a through hole, so it might not etch all the way through anyway.  The centre panel will be covered by a tip-up seat so I've etched it on the back instead, where it may be visible down the aisle of the passenger saloon.

 

I'm using Powerpoint because it has less of the annoying automatic formatting etc. of Word.  Although this may be  a basic drawing tool, there are still elements of CAD, such as being able to align shapes, accurately adjust their dimensions or scale them up and down.

 

Next here's the same drawing converted into a front and back pair of 'masks' which could be used as photo-tools for the more common photo-etching process, or in my case for toner transfer direct to the brass.

 

 

I added a 100mm long box to ensure it's printed to scale, and crosshairs for aligning the two masks on each side of the brass.  You can see how fine some of the parts are, in particular the window frames for the windscreen (centre).

 

I found some sticky labels which came on an A4 sheet of waxed paper.  The labels were removed, which seems a bit wasteful but Iv'e had them for years and they were never going to get used.  From experience, it's easier to get the toner to transfer from waxed paper than from OHP* transparencies, which is another option.

 

 

Next came a trip to an undisclosed location to use a laser printer.  It doesn't half get you some funny looks in the office when you keep toddling back and forth to the printer, adjusting the settings until the print comes out at the right scale, on the right side of the sheet, and without the thin, floppy paper getting jammed in the mechanism.  After a few false starts I eventually found this worked better when my paper came from the main tray underneath, rather than the special one at the side which, on this printer, caused the paper to take an S-shaped path which was frought with navigational difficulties.

 

 

Eventually I had what I wanted.  Not quite as many copies as I'd ideally like for trial and error at the next stage, but I decided to make a strategic exit before a work colleague asked me why I was furtively fluttering sheets of strange patterns around on my desk.  The LH sheet is detailing parts for my tram, the RH one is some experimental tram bogie frames and a test etch to experiment with different shapes and dimensions.

 

Cheers,

 

Will

[CWJ]

* Overhead Projector. If you don't know what this means, ask your Dad!

[CWJ]

Step 2 is the trickiest part of the whole process in my experience - transferring the pattern to the brass sheet.

 

In my earlier attempts I found that a laminator wasn't very effective, so I used a domestic iron instead.  However, that was when I was still  trying to use OHP transparencies rather than label paper.  According to the internet, laminators operate at around 100 to 150 degrees C, whereas laser printers melt the toner onto the paper at up to 400 degrees ...BUT apparently slower printers can use lower temperatures.  I thought I'd try the laminator with label paper, as it just seems a much more consistent and controlled technique compared with a bloke waggling an iron around.

 

Here's my starting point.  A mirror image of each side of the etched fret, printed on label paper.

 

 

This one contains the door vestibule floor and partitions, a destination blind panel and a couple of handbrake wheels.  As this is a practice run, I'm using one of the rejects from my stressful undercover printing experience which has a smudged bit at the top.

 

This is folded in half so that the crosshairs align.  Holding it up to a window made this fairly easy, as the paper's pretty thin.

 

 

Here's my victim: a sheet of 10 thou brass, which is just over 0.25mm.  I rubbed it down with the finest wet and dry paper I had, 1200 grit, used wet.

 

 

...and into the laminator it goes.  Fingers crossed everyone...

 

 

[RIP Eileen's Emporium]

 

Remembering my unsuccessful attempts 11 years ago, I ran it through the laminator twice this time.  The result, almost inevitably, wasn't great:

 

 

The worst areas seem to be where the paper has wrinkled and lifted away from the brass.  On the plus side, where the toner has transferred to the brass it has done so neatly, without melting into a distorted shape as happened with my ironed efforts in the past.

 

Attempt No.2, this time, and it's another rejected print-out just for testing purposes:

 

 

This time I used masking tape to hold things together a bit more securely.  I didn't think sellotape and a laminator would be a healthy combination. 

 

 

I also ran it through the laminator 3 times to ensure all the toner is softened.  The result:

 

 

I was pretty happy with this.  Still lots of little flecks, and that vertical line on the bottom-left which was where the edge of the labels was situated on the backing paper, causing a tiny crease.  Remember the 'ghosting' effect is caused by me messing up the print, not by this stage going wrong.

 

To be continued...

[CWJ]

So if 3 runs through the laminator worked better than 2, surely 4 would be even better?  And my toner would be neatly transferred to the brass without all those little missing flecks?  Here we go...

 

 

Ah.  Useless.  At first I couldn't think why this would be so much worse than my last attempt.  Surely a little extra time in the laminator couldn't actually prevent the toner from sticking to the brass?  Then I realised my error.  Before my first two attempts I'd rubbed the brass down with wet and dry, but before this one I'd only removed the toner with a (used) pan scrub in the kitchen sink and then dried it on the tea towel.  Presumably that had left a little greasy residue on the surface.

 

Onwards and upwards!  Out came the 1200-grit wet and dry, and I prepared another paper mask.  This one's for a future DMU project and contains some grilles, footsteps and headlight cluster surrounds.  I'd run out of defective ones so this is a decent print-out.

 

 

I went back to 3 passes through the laminator this time, as that had worked fairly well.  This time, I watched closely and could actually see the paper waving up and down as it was squeezed through the machine, preventing it from staying put on the brass.  So the result wasn't great:

 

 

I had noticed by this stage that all my results seemed to have one edge worse than the rest of the image, like the LHS of the one above.  The penny dropped, and I realised that the side where the paper is folded might be trying to unfold, causing the paper to pop up off the surface of the brass as soon as it comes out of the laminator.

 

...and so, with my patience not quite expired yet but with no more spare masks to play with, I decided to take the plunge and transfer my 'good' images onto the brass.  I had nothing to lose.  Off came the Eileen's Emporium sticker so I could produce all three frets.

 

Again I ran all three through the laminator 3 times, but this time I cut the folded edge off the masks after wrapping them around the brass and securing with tape.  The results were mixed.  In order of worst to best:

 

 

The bogie frames (right, with an unused printed mask on the left) are not useable.  The LH side could be salvageable by touching in with a marker pen, but not on the right! 

 

 

The main detail etch is not a complete disaster actually.  With a fine marker pen I could touch in the speckly bits, where they matter.  I couldn't use the tram controller which is on the top-left, but that wouldn't be difficult to knock up out of plastic bits and pieces anyway.  The things I could only possibly make out of etched metal are the window frames, and they're OK.

 

 

And finally, finishing on a high, I'm really happy with how this one came out.  I know it looks scruffy close up, but you have to remember this thing's less than an inch wide, and none of the scruffy bits are too fine to be touched in with a marker pen.

[CWJ]

So, what have I learnt so far?

 

Positives:

• The laminator doesn't 'melt' the image like the iron did, so the shape of the fine detail is really good.
• It is possible to transfer a reasonably usable image onto brass this way (even if I only managed it once!)
• I'm convinced that by tweaking different parts of the process until everything is as good as it can be, I could eventually get decent results.  Never as good as a professional photo-etch of course, but useable for parts that will be viewed from a safe distance 😉

 

Negatives:

• Even my best examples are scattered with little flecks of missing toner.  I'm not sure what might cure this, as it doesn't seem related to the finish of the brass... perhaps the waxed surface of the paper has bits that are more sticky than others, and don't like to let go of the toner, or perhaps I'm not softening all of the toner enough and need more heat?
• One edge of each fret is noticeably worse than the rest of it.  See the right-hand side of each in the photo below.  These were all on the leading edge as the brass entered the laminator, so perhaps something to do with temperature, pressure of the roller, or the paper lifting.  The only one which didn't have this problem was the last photo in my previous post, which had more of a border of 'spare brass' around it.  Next time I could perhaps try cutting the brass a bit larger than the image and see if that helps.

 

 

What next?

 

I'll see if I can tidy up some of these with a fine permanent marker and have a go at etching.  The bogie frames will need to be re-done though so I might have another go with the laser printer, laminator and a bigger sheet of brass.

 

In the meantime if anyone has any experience of this method it would be great to hear how you got on!

 

Cheers,

 

Will

[ianmaccormac]

https://www.amazon.co.uk/Portable-Photosensitive-30cm×5m-Production-Photoresist/dp/B07MKWTK1G

 

dry film to laminate onto the brass?

Cheers, ian

[CWJ]

That's interesting, Ian, I had always assumed the photoresist had to be painted onto the brass in liquid form. That film would be easier to use.  If I do end up photo-etching, I'll give it a try 👍

 

The thing that draws me to toner transfer, as opposed to photo-exposure, is that in theory it involves fewer stages and no need for developing chemicals or a UV lightbox. Of course that theory is only of any use if it works reliably!

 

Your post prompted me to have a good browse on PCB etching forums to find out if there have been any developments, and I found this one which was particularly helpful: https://hackaday.com/2016/09/12/take-your-pcbs-from-good-to-great-toner-transfer/

 

Basically this chap's first photo shows the difference between rubbish toner transfer like mine, and the kind of standard I'm trying to achieve. Combining his experience and some other feedback in his comments section at the end, there are a few things I could try:

 

1. Preheating the brass beforehand.

2. Applying heavy pressure using a rolling pin.

3. Go back to using the iron, but using low temperature and high pressure.

4. Pre-etching the brass to help the toner adhere to the different surface chemistry (although this extra stage would kind of defeat the object of keeping this process simple).

 

 

If I get time this weekend I might tinker with some of these options before I start etching the frets from my previous post next week. Wtach this space!

 

Cheers,

 

Will

 

[ianmaccormac]

An interesting read! Cheers and good luck, Ian

 

[Chas Levin]

Following with interest as home etching is something I've thought about from time to time - good luck and looking forward to further news...

[sej]

Following with great interest!

 

Cheers

Simon