Electro etching

I have been thinking of Electro etching the 360deg scale around my Pillar Tool Table.

Does anyone know of a supplier for the masks ?

Cheers

Peter

Could the masking be done photographically, perhaps using a cheap circular degree perspex disc from W H Smith(?), in the area of items aimed at school usage.

Thank you, but it needs to be a linear scale, essentially a strip to wrap around the circumference to etch through.

Would this help?

https://sundialsoc.org.uk/sundial-maker/photoetching-for-sundial-makers/

David

I wonder if I am the only one thinking 'What material is going to be etched? - What electrolyte is in mind?'

But then, we all enjoy a good guessing game now and then.

Regards, Tim

Thanks David. I enjoyed watching it. I´ve even got Ferric Chloride. I´ḿ familiar with the process and have photo etched in the past. From his comments in the Postscript, it sounds like he is making his own masks.

Thanks

Peter

Given that I mentioned that I was wanting to etch the GHT Pillar Tool table, I assumed that most people knew that these are made of cast iron.

Sealing the mask around a curved surface sounds interesting

At the risk of being tedious, here is another video that I found helpful with my clocks.

https://www.youtube.com/watch?v=qpy5O0b7cL8&list=PLZioPDnFPNsETq9h35dgQq80Ryx-beOli&index=9

David

Yuo could use a photo sensitive resist like this:

https://uk.farnell.com/kontakt-chemie/positiv-20-200ml/positive-resist-photo-sensitive/dp/801010

and use a negative of the sacle to expose it Devlop (in sodium hydroxide/ casutic soda typically) then etch with ferric cloride. Scle cn be printed on clear film in a laser printer.

Robert G8RPI.

Hi, I've had some success with electro etching nameplates for locos. I use Press n peel blue [ebay]. The print has to be done on a laser printer. The etching is done in copper sulphate solution, I found it best to do it face down so the material etched away falls off. It doesn't take long or much current, I used a small variable power supply. There was a good article about it in MEW some years back.

The guy in the video below uses a vinyl stencil (7:28 if it doesn't go there on its own). I see that there are plenty of places offering a cutting service, but haven't done it myself, so can't make any personal recommendations.

Thank you. Yes, I had seen that. The sort of thing I need would be a straight strip, as it goes around the thickness of the table.

I don't think there'd be a problem cutting a long strip (one would need to produce the artwork somehow though). It might be a bit tricky to get the scaling right to exactly match the table circumference. Maybe not so much of an issue if you were only proposing to etch the numerals, but (I think) quite challenging for the graduations.

Sorry Peter, mis understood what was required.

Now I do and I would go about in similar fashion to that suggested by Andy G, in that as I have dividing gear, I would engrave the divisions and etch numbers and lettering, thus getting the best of both worlds, in my opinion. Certainly, dividing and engraving with some sort of scratching implement will overcome problem of matching a flat scale to a circumferential position. Etching letters and numbers would create acceptably good appearance.

John