Cleaning up a starrett square

I have my fathers set from his work and want to keep using it. I have some what i think is very old rust turned black on both narrow edges and want to remove this properly. Looking for suggestions.

Thanks.

Brian

To do this I use a fixture on a surface plate. I run the square along its edge over abrasive with a fixture maintaining perpendicular.

I then check the square on another surface plate with a 90 degree angle plate which has been hand scraped into accuracy. I shine a light behind the square and turn the lights off in the shop. When the two agree, then the square is accurate.

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Originally Posted by Brian Holcombe

To do this I use a fixture on a surface plate. I run the square along its edge over abrasive with a fixture maintaining perpendicular.

I then check the square on another surface plate with a 90 degree angle plate which has been hand scraped into accuracy. I shine a light behind the square and turn the lights off in the shop. When the two agree, then the square is accurate.

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It's square, the buildup on the edge drives me nuts when checking if a cut is square. What type of fixture could I use to hold it 90 degrees?

Yeah, soon as you start to strip the rust off you will take it out of square unless you can somehow do so with perfect evenness. So, you have to do this while checking your effort.

You can use a 1-2-3 block or 2-4-6 block clamped to a scraped beam or bolted to a fixture plate.

Drop an email to repair@starrett.com and see what they say.

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Originally Posted by Rich Engelhardt

Drop an email to repair@starrett.com and see what they say.

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Thanks great idea. brian