Thread: Vinegar Ate My Calipers

I submerged the calipers in White Vinegar to remove some slight surface rust. My intention was to clean them up and then spray some clear lacquer on them to slow down any further rust. Yep you guessed it and forgot, for about a week, to pull them out of the vinegar. The vinegar ate into the spring that keeps tension on the 2 legs rendering the calipers totally useless.<br>&nbsp;Question; what can I use for new springs? It looks like a short piece of spring steel pipe with a cut to allow the legs to be held in place.<br><br>Anyone got any clues?&nbsp;

Can't help you with a replacement spring, however l had a similar issue with the spring on a pair of dividers in an electrolysis bath, the spring just cracked in half ( hydrogen embrittlement?)
Pete

Try a tape measure blade or the spring from the same.

I made a new spring from mine out of . . . . . . . . some spring steel from a defunct retractable hose reel - gee that stuff has been useful. It was a bugger to bend into shape but I did it eventually because I used a piece that was almost already the right shape from the very inside of the coiled spring.

As for vinegar - like any acid based removal it can be hit and miss. It can seem to do nothing for a while and then it takes off when you are least ready for it and left with a potted or destroyed object. Probably better to use molasses as it works in a different way and does not generate hydrogen. Hydrogen embrittlement during Electrolysis can be minimised if much lower Voltages are used. Car battery chargers etc are too high a V and generate excess H - even just a few V is all that is needed to get it to work. I've been using 6V and 3A for small objects with some success.

I know you all have been sitting on the edge of your chairs waiting for me to give you an update.....the spring material in tape measures is WAY too thin (less than half a millimetre) a mate dropped in and I showed him and he suggested I use an old hole saw cutter. I located a couple that look promising so tomorrow I will attack and see if I can make them work

That sounds a good suggestion Rod, Good luck with it and we look forward to your report on the result.
Rob

A hole saw cutter for timber may be OK but one for steel I would think would be way too thick and stiff.

Another option is a clock spring from a drill press or the quill return spring from a mill, if you had a broken one laying around..

Good luck!

Simon

Well I suppose you blokes have had a sleepless night wondering how I was going with the "fix" needed to make these calipers usable again. I hunted around and found a few hole saws that I foolishly bought because they were cheap and turned out to be crap. I nipped up each one in the lathe just to safely hold them while I cut the teeth and the back piece off. I then cut through the little hole long wise there by making the "hinge". While trying to get the spring (hole saw) onto the caliper legs I lost the hub so had to machine some new ones out of mild steel rod. A bit tricky but had success after some perseverance.

The next thing was to sand blast the surface rust off then give them a heavy coat of lacquer.I should have used this method to begin with and would have saved me from the remedy I have just performed.

I used a few 25 mm hole saws as well as a 22 mm

Originally Posted by chambezio

Well I suppose you blokes have had a sleepless night wondering how I was going with the "fix" needed to make these calipers usable again. I hunted around and found a few hole saws that I foolishly bought because they were cheap and turned out to be crap. I nipped up each one in the lathe just to safely hold them while I cut the teeth and the back piece off. I then cut through the little hole long wise there by making the "hinge". While trying to get the spring (hole saw) onto the caliper legs I lost the hub so had to machine some new ones out of mild steel rod. A bit tricky but had success after some perseverance.

The next thing was to sand blast the surface rust off then give them a heavy coat of lacquer.I should have used this method to begin with and would have saved me from the remedy I have just performed.

I used a few 25 mm hole saws as well as a 22 mm

Good one Chambezio

Thanks Rod excellent save