Need Help: Re-Inking Machinist's Scales

[extropic]

I got some 6" Starrett scales (C316R) in a lot of industrial surplus. A previous owner had applied some type of label (about .25" x 1.00 ") on one end of one side of each scale. The labels were overcoated with a tough, clear resin product which was also stuck to the scale itself.

To removed the resin, I scraped it with a razor blade. Where the resin had overcoated it, the black "ink", in the scale graduations, came off with the resin.

The scales have the Satin Chrome finish. Where the "ink" is removed, the scale is difficult to read because of poor contrast.

I want to re-apply some sort of black to the engraved graduations. Ideally the black would be as durable as the factory stuff.

I'd like some referrals regarding specifically what black material I should use and any suggestions regarding process/technique.

I searched Google and Youtube for "re-inking machinist's scale" and saw nothing useful.

I have essentially zero experience with paint pens, but that would be my first try if I don't get some better ideas here. I expect that the trick will be to wipe off the excess, while it's still wet, while leaving the engravings still black. I'm guessing that using a dry (no solvent) bond paper, to wipe the excess black off, will be my first try. Not sure what to do if that's a bust. Maybe add a VERY little bit (2 drops?) of lacquer thinner on the bond paper.

Any experience out there? Other ideas?

TIA

 

[francist]

A bit of solvent on the paper blotter will be advantageous otherwise the ink/paint will just smear. I used to have a small pad (like a stamp pad, actually) that I could tamp my block in to just get a whisper of solvent to the surface. A hard rubber block with a wrap of old telephone book paper works very well — the paper is least likely to scratch fine surfaces.

For ink, a lacquer works the best as the pigment particles will be very fine — oil paints are quite coarse in comparison so not as likely to fill the fine grooves as well. I’ve also used a ceramic paint (for painting on glass and ceramics) that worked well too — it was almost like a dye more than a paint.

Technique will vary but I found it best to wait a bit (10 to 30 minutes) for the paint to take a set and start to tack up a bit before trying to scud the excess. Paint has a lot of bulk with the solvent in so it’ll sit close to the surface edges of the relief bit as the solvent evaporates the paint recedes ( less volume, eh) and you have less smearing.

Used to paint key fobs and signs for hotels and things in another life. Hours of sitting at my kitchen table with a pie plate of xylene in front of me (oh yeah, xylene works very nicely and isn’t quite as hot as acetone for flashing off).

Good luck. Shallow recesses are harder than they look so you may need to do some experimenting to get satisfactory results.

-frank

Oh, and only use the paper once. One pass and then change to a fresh one so you’re not just smearing the old ink around. And no “scrubbing”, just a clean pass over top.

 

[extropic]

@francist
Thanks Frank. I appreciate your advise.

Lacquer it is then. I found the linked item (Gloss Black) on Amazon. They also have Semi-Gloss and Flat. Do you have an opinion whether one would be better over the others? What I'm wondering is whether or not the level of gloss (what ever effects that) will be best suited to my purpose.

Do you think the hobby supply type lacquer is probably suitable, or would you suggest an alternative source?

Phone books? LOL, I threw away (recycled) about a foot high stack of phone books a couple of years ago. I'll try to scare one up.

https://www.amazon.com/Tamiya-82101-Lacquer-Paint-Black/dp/B08127Z16T/ref=sr_1_4?keywords=black+lacquer+paint&qid=1674624873&sr=8-4

 

[darkzero]

Markal Laquer Stiks. Never needed to use em on a micrometer yet but I've used them on various things with great results. So much easier trying to fill in with paint then wiping off excess.... which I have done in the past.

https://www.hobby-machinist.com/thr...nes-on-a-micrometer.102995/page-2#post-995594

 

[extropic]

@darkzero
Thanks Will.

I like easy. I'm fair to middling at easy.

 

[Razzle]

+1 for lacquer sticks. I refilled the markings on my starrett 98-8 machinist level bubble. Worked great. FYI you need to scrape off the end of the stick until you get to the soft stuff. The end of the stick gets hard as it dries. You need to get to the stuff that is like a crayon consistency.

 

[francist]

Do you think the hobby supply type lacquer is probably suitable, or would you suggest an alternative source?

I don’t see why that wouldn’t work, and for your application where the graduation lines are so narrow anyways I don’t know if you’d be able to see a difference in the gloss. I used to just spray a little from a spray bomb into into the cap and dip out with a fine brush from there depending on the quantity needed. I think if I were forced to choose one I’d probably go with the flat but that’s just a gut response more than anything. Sometimes we would darken-in engravings with a product called stove black. It imparted no gloss whatsoever but I don’t know if that’s even around anymore. A suitable substitute for telephone book pages would be a pad of the yellow typewriter paper — you do have some of that don’t you?

-f

 

[ChazzC]

+1 for lacquer sticks. I refilled the markings on my starrett 98-8 machinist level bubble. Worked great. FYI you need to scrape off the end of the stick until you get to the soft stuff. The end of the stick gets hard as it dries. You need to get to the stuff that is like a crayon consistency.

Me three – I've used both black & white to cleanup old graduations. You do need to make sure that the existing lines or whatever are clean.

Starrett uses I'm guessing a proprietary enamel paint during manufacturing.

 

[extropic]

Me three – I've used both black & white to cleanup old graduations. You do need to make sure that the existing lines or whatever are clean.

Starrett uses I'm guessing a proprietary enamel paint during manufacturing.

Thanks for the video link. They make it look easy.

 

[extropic]

I ordered both today, a small bottle of lacquer and a Lacquer-Stik.

I'll report back in a few days and try to describe my experience.
I have about 1/2 dozen scales to do, so I can try different techniques.

Thank you all again.