[Shiny]

There is a recent thread about labels that reminded me of a project I abandoned because I got stuck before I really "needed" a solution.

The goal was to reproduce gauge graphics - I was working on a dash tach at the time and thought it was an interesting challenge.

Warning - I don't have a solution but will babble in hopes of getting some ideas.

I wanted a method to print graphics onto the curved surfaces of the black-painted stamped steel (and recessed) gauge faces. I don't know the process used originally, but suspect it was pad printing. I'm sure there are modern commercial methods but I wanted a cheap DIY process.

I did not want to use anything that had a full label like a vinyl decal. To me, this would never look like the original, especially if one "decal'ed" gauge sat next to an original. There's a world of these vinyl gauge overlays out there, but I hoped for something that would get white letters directly onto the painted face like the originals.

I started to pursue a dry transfer method... basically graphics are printed onto a carrier or "release" paper and then rubbed onto the substrate (rub-on graphics).

There are suppliers for these graphics that will custom print and send you a dry transfer "decal" but it's expensive - like $150 for an 8.5 x 11 page in 2 colors. Not so hobby-friendly for me.

It has been many years but I did find a DIY process and material supplier that included white "ink":

Link to DecalPro fx

The process is a little complicated but clever. It requires a laser printer or copier so cannot use ink-jet alone. It also requires a hot-roll laminator.

I have some of the material but never followed through so can't say if it works or not. Unfortunately, it seems the company is out of business but perhaps there are others like it.

I'd love to hear other DIY-friendly ideas for printing white letters onto the black-painted gauge faces.

Maybe a die-cut temporary vinyl label used as a mask for painting would work? I'm a little familiar with "Cricut" machines but never explored...

I have done some screen-printing, and suspect that might also work, but I'm used to the screen/stencil being supported by a frame. This wouldn't work well to reach down into a recessed gauge face stamping, but maybe there's a clever way to do this? Maybe an unsupported screen could be made to work?

I'm interested in how you have done this, have other ideas, or if there's already an inexpensive source for either DIY gauge graphics or reproduced faces that are true to the originals.

Mike

[Formulabruce]

https://www.instrument-specialties.com/
Why no Home brew ideas? They use a lithography which actually repels ink where you dont want it making the letters crisp.
The only thing I have tried is to use a model type decal which is water based..
Good luck with getting something to your satisfaction...

[Shiny]

Originally Posted by Formulabruce

https://www.instrument-specialties.com/
Why no Home brew ideas? They use a lithography which actually repels ink where you dont want it making the letters crisp.
The only thing I have tried is to use a model type decal which is water based..
Good luck with getting something to your satisfaction...

Thanks for the reply.

Yes, they know how to do it and the results look great. What do they charge for a single clock or dash-tach face? I guess I could call them and try to learn more from experts!

What do you mean by "no home brew ideas?".

As I glanced through their site, they mention both silk-screen and "photochemical" processes to apply the graphics. You mention "lithography... repels ink", which may be the same.

More rambling babble...

Silk-screen may be do-able for DIY.. I'll look into materials. Way back when I did this for electronic circuit fab (hybrids), we would buy photoemulsion-coated screens and expose them to artwork. Then you just rinsed off the emulsion where it didn't harden to form the pattern. The trick for a gauge would be to hold the screen down inside the stamped plate. Sounds tricky to me but maybe it's routine.

As to photochemical processes..

I understand electrophotography (copiers, laser printers) that uses dry toner and hot-roll fusers, but not sure how this could be used on a stamped metal gauge face. There are white toner cartridges for some machines... would require a transfer process of some type, though.

A lithography that repels ink? So maybe they have a laser etcher that can open up the graphics area in a hydrophobic or temporary film applied to the gauge face? Anyone know if a hobby laser etcher can project an accurate image at say, an inch away from the working surface? Maybe a laser etcher could open a mask in a flexible polymer film that "repels" ink? PSA-coated polypropylene films might be out there.. this idea might be worth investigating. This would be a lot like silk-screening.

A liquid or film photo-resist could also be applied, then exposed to form a mask if there was either a collimated exposure source or a flexible contact mask. After that, I'm not sure how the process would play out as photoresists I'm familiar with don't just peel off.

Maybe some type of powder-coating could work if you could selectively deposit the toner. For example, if you could apply a stencil, apply powder, lift the stencil, bake to fuse. This could be very durable... something else for me to think about.

[Shiny]

Here is a product I just stumbled on that allows a "dry transfer" method to create a screening stencil... simpler than exposing and developing a photoemulsion.

It requires printing on a laser printer as the transfer starts with the toner on the printed page.

This is very similar to the DecalPro process but would allow screen printing an ink onto the gauge face instead of transferring a dry film. My guess is a UV-cured ink could be very durable and look near original.

I will call this company and talk to them. They show a flat thermal transfer press. If it can work with a hot-roll laminator, I may order some of the material and try it out.

It would still require printing with an "unsupported" screen, which could be tricky but that is challenge number 2 or 3...

Link to RhinoScreen 2.0 Video on YouTube

[Shiny]

Talked to tech support at Rhino and unfortunately, their material won't work with a hot-roll laminator. It uses two films with different melting temperatures so you can't just turn the heat up and the time down.

I would need a temperature-controlled press (like is used for t-shirt printing) and I don't have one.

Any ideas on what I could use as a cheap heated press? Work area would only need to be the size of a gauge face.