scribbles

you can gouge the metal, and cause more sever inaccuracies, or heat the metal and warp it.

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Kudzu

OK, I see where you coming from.

I have wire brushed 1,000 of lbs of steel and cast iron restoring old machines and tools. Your not going to damage a ruler with a wire wheel unless you do something really dumb. It will actually impart a bit of a polished finish. The two I use now were wire brushed because I couldn't read them when I got them.

Sanding, if you used a belt sander or something to aggressive I could see over heating it or sanding it to the point there were not lines left. But a light sanding isn't going to hurt it. I have cleaned up old ones with a ROS even though it is not my first choice.

This isn't arguing, but I don't see how you are going to change the accuracy. Assuming the marks/groves are recessed in the metal your not going to move them by cleaning it with a wire brush (my first choice) or a light sanding. It would take something pretty aggressive to heat it enough to make it move.

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It seems I have reached the point where I can forget things easily....of course this just means there is always room for more.

GeorgeC

I really must be out of touch. Or is it just that this modern generation lives by abreviations without understanding that all of us do not know what they mean.

It seems that I have to ask about an abreviation at least 2 or 3 times a week.

This time it is What is a "ROS?"

George

pianoman

A combination square has a curf in the rule and a keeper as a slide mechanizum...sorry about the spelling...any sanding or power wire brushing may roll off the edges hence, rendering it even more inaccurate. This is only my opinion. Still, old tools are like blue jeans...hard to get rid of...Rick

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Kudzu

Random Orbital Sander

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It seems I have reached the point where I can forget things easily....of course this just means there is always room for more.

Kudzu

I don't follow you there. I know what you talking about but I don't see how that would make the marks on the ruler inaccurate. What am I missing?

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It seems I have reached the point where I can forget things easily....of course this just means there is always room for more.

Sleeper

I agree with Kudzu, the curf and the keeper have nothing to do the accuracy. They are just a way to hold the rule tight up against the square surface.
The accuracy of the square depends on the edge of the rule being straight and the inside surface of square head being free of debris. The only way the square is going to change is if you grind or over sand the edge so that it isn't straight anymore. An unless maybe the rule was cold stamped out of a press without any machining, which isn’t very accurate in the first place, rounding of the edge isn’t going to change the square.
The accuracy of the markings depends on the accuracy of the manufacturing techniques. They are not going to move or change unless you grind the ends.
We are talking about cleaning the rust off, not reshaping the square.
I also wanted to add that if you are the type to overheat the rule in a grinder to remove rust, then maybe you shouldn’t touch power tools.

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JohnnyB
"I do what I do well, but I still like to dabble in what I don’t do well"