stuckinthemud
Established Member
The measurement marks on my old callipers are getting difficult to read, how do I re-black them?
Renew measuring marks
- Thread starter stuckinthemud
- Start date
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can you show a picture? The typical thing if they're recessed is to etch them with some kind of bluing agent or something acidic and then polish the surface. This supposes two things:
1) that the parts needing to be refreshed are recessed and clean enough to be etched
2) that you have the means to abrade the surface above the edge in a way that will leave it neat without reaching into the etched area. For example, sandpaper will often flex even on a block and may squish into the markings and either push around a slurry and remove the etch or abrade it directly.
I used to refresh etches on razors or saws from time to time, but decided not to do it as there needs to be enough depth and it kind of reminds me of using one of those bottles of white tinted stuff to make old shoes look new.
But on a measuring tool, it actually matters. (it's a pain on a razor, too, because the surface is curved and if you try to buff the etchant off of the surface, the buffing bob just buffs the inside of the etch, too).
stuckinthemud
Established Member
If you could get the thing really clean and use a very fine sanding media held tight to a hard block, I think etchant, like phosphoric gun blue would do the job. It may remain in the pits, though, leaving them dark.
There's seemingly plenty of depth there, though.
Not sure what would've been used industrially. I've seen razors having their etch decorated and the stuff being used looks more like paint, but it must be reactive like a gun blue - just thicker, as it's not just paint. I'd clean it up as much as possible and then scrub all of it with something like acetone and go from there.
There's seemingly plenty of depth there, though.
Not sure what would've been used industrially. I've seen razors having their etch decorated and the stuff being used looks more like paint, but it must be reactive like a gun blue - just thicker, as it's not just paint. I'd clean it up as much as possible and then scrub all of it with something like acetone and go from there.
Jacob
What goes around comes around.
They look even worse than mine! Draper - had them for years and they work perfectly. Maybe replace them? A fiver or so on ebay.
I wouldn't bother with digital or plastic.
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stuckinthemud
Established Member
Replacing them would be very practical but unnecessary as I also have a very cheap, very accurate plastic set. I just like using these, dunno why, so refurbishing them seems like a nice project. Could they be cleaned with a diamond stone?
rogxwhit
Established Member
Would you really destroy that delectable patina? Are you familiar with the Japanese concept of wabi sabi?
Jacob
What goes around comes around.
Yep it'd halve the value. Best left alone!
rogxwhit
Established Member
Could you define the term 'value' there, Jacob? You should always define your terms, otherwise communication can get woolly ...
Jacob
What goes around comes around.
stuckinthemud
Established Member
Wasn’t it a fiver on eBay???
Mmm delicate patina or easy to read?
Mmm delicate patina or easy to read?
rogxwhit
Established Member
Buy a second one, then one can have the patina and the other be easy to read ...
yes, but diamond is a tough thing to use for surface conditioning .It tends to find the high spots only and cut a bunch of narrow grooves that don't look right.
Fine PSA roll on hardwood would be my choice to start with here, but PSA roll is one of those things where it's cheap by the unit, but only sold at larger units. If it's sold in small units, it's not cheap. 400 grit or so is where I'd start with this. Clean everything off from time to time if you go that route so that the dust can't end up rolling in the recesses and abrading them, too, along with separated grit.
I never had much luck with diamonds to surface finish things.
Inspector
Nyuck, Nyuck, Nyuck!
Take some #0000 steel wool with some oil or solvent and carefully rub them enough to remove the grime and still leave the patina. If you want you can try and fill the lines a little with some black paint or nail polish and wipe off the excess. I think the steel wool alone will give you enough contrast see the markings better.
Pete
Pete
stuckinthemud
Established Member
Just had a quick look at getting another but could only find an out of stock listing on Etsy where it sold for £41:00 !!! Maybe having a rethink on the patina……
Last time they were cleaned (over a year ago) I used 0000 wire wool and it helped a lot but I used a sharpie to re-ink and it rubbed out pretty quickly. Didn’t use a solvent but I will try the wire wool with rubbing alcohol (hand sanitizer).
Last time they were cleaned (over a year ago) I used 0000 wire wool and it helped a lot but I used a sharpie to re-ink and it rubbed out pretty quickly. Didn’t use a solvent but I will try the wire wool with rubbing alcohol (hand sanitizer).
I just did the five minute method I mentioned. The one thing that it does require that you may not have is cold blue for guns, but you would have a lifetime in the smallest container.
Here is a starrett rule that's not got great contrast before.
apologies, it's upside down.
Process - clean the surface off, not with anything very abrasive, in my case a gray scotchbrite but only to ensure the cold blue etch was getting everything. Oil or finish will block it some.
Here's what we have available in the states, or one of the types - this one is popular - oxpho blue. you can see the rule getting dark. I got it a bit darker than this but I don't want the etchant to work too deep. It has to be phosphoric acid, it smells like someone with a gas problem and a strange diet.
And then sanded off with a hard flat wood block and 1200 grit automotive paper, which is definitely offered in cheap small packages, just using water as the lubricant. IF any slurry built up, I cleaned off the rule to prevent it from abrading the bottoms of the marks.
Here is the result. One could go further, but there's no need and it's just cheating room to do it again later. I'm ok with leaving the small pits vs. accidentally getting to the bottom of the marks.
The cold blue doesn't really do the india black job that an etchant paint would, but it's good enough. You can see that some of the marks in the rule were already good, just with the surface cark, but the 11 and 1 and such at the end no longer had their etch paint and have been improved a significant amount.
Certainly this fits in one of my "think for a minute" categories. I have the materials on hand, but realistically, it takes less time to do this than it does to do a look-around and find the best price for something - that itself often ends in having to search harder to get past the first five overpriced advertiser links.
5 minutes, no kidding (I actually used spit, but water would be more appropriate had I had any in the shop).
Here is a starrett rule that's not got great contrast before.
apologies, it's upside down.
Process - clean the surface off, not with anything very abrasive, in my case a gray scotchbrite but only to ensure the cold blue etch was getting everything. Oil or finish will block it some.
Here's what we have available in the states, or one of the types - this one is popular - oxpho blue. you can see the rule getting dark. I got it a bit darker than this but I don't want the etchant to work too deep. It has to be phosphoric acid, it smells like someone with a gas problem and a strange diet.
And then sanded off with a hard flat wood block and 1200 grit automotive paper, which is definitely offered in cheap small packages, just using water as the lubricant. IF any slurry built up, I cleaned off the rule to prevent it from abrading the bottoms of the marks.
Here is the result. One could go further, but there's no need and it's just cheating room to do it again later. I'm ok with leaving the small pits vs. accidentally getting to the bottom of the marks.
The cold blue doesn't really do the india black job that an etchant paint would, but it's good enough. You can see that some of the marks in the rule were already good, just with the surface cark, but the 11 and 1 and such at the end no longer had their etch paint and have been improved a significant amount.
Certainly this fits in one of my "think for a minute" categories. I have the materials on hand, but realistically, it takes less time to do this than it does to do a look-around and find the best price for something - that itself often ends in having to search harder to get past the first five overpriced advertiser links.
5 minutes, no kidding (I actually used spit, but water would be more appropriate had I had any in the shop).
Jacob
What goes around comes around.
It was a long time ago. Probably something like 5/- from Woolworths.
I'd just rub it up a bit with my thumb - shine up the flat bits a touch but leave the etchings dark.
Doesn't do to overthink these things!
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Inspector
Nyuck, Nyuck, Nyuck!
The solvents I had in mind are Varsol, Stoddard, mineral spirits, paint thinners etc. They leave just a hint of oil behind that slows or stops corrosion. Alcohol in any form will degrease and leave the metal bare, thus prone to rusting but use it if you like it better.
Pete
Pete
by the way, thanks for bringing this up. I've got a couple of older squares that are kind of filthy like this one and I hadn't really considered doing anything about it. They are hardened with hardened heads, which are just bodacious for close hand work because they never seem to really wear or get out of square and their action is super slick. But they do get harder to see. now my rule is refreshed and I won't just hang with the head behind the others.
