What do do with my slightly beat up cylindrical square?

[macardoso]

I bought a 3"x6" Fowler Master Grade cylindrical square from HGR (listed as a weight - lol) for $16. It is in pretty good shape with the exception of a few rust spots and one ding on the square face.

I've used it a few times to tram my mill and set the tailstock on my lathe and it is awesome when it is needed.

I'd like to clean it up a bit but not sure how to go about it. The rust stands slightly proud of the surface so it does affect accuracy if I hit those spots. Any tips? If I owned a set of precision ground flat stones, this would be the perfect application I think.

I oiled it up to prevent further rust hence why it looks dirty.







Here is the actual "ding" in the surface.

 

[Aukai]

If you get the rust below surface chemically I'm sure there are quite a few degrees of circumference that are unmarred. I think it's a score....but that's me

 

[Nutfarmer]

Be careful with any chemical rust remover even the ones that are supposed to be safe. I lost a couple of gauge blocks by soaking them over night in vapo rust . It destroyed the finish. Shorter amount of time and watching it closely might work. The ding can be carefully removed with a fine stone. It should work just fine by avoiding the rust spot on the side

 

[macardoso]

If you get the rust below surface chemically I'm sure there are quite a few degrees of circumference that are unmarred. I think it's a score....but that's me

I think the accuracy of the whole unit is still very good. I ran it between centers on my lathe and my tenths indicator didn’t budge at all. The rust is only in a few tiny locations on the perimeter. My biggest concern was the rust on the square faces. If it sits proud of the surface it would cause the cylinder to no longer be square.

Id eventually like to build a Squareness comparator and use this as the master reference.

 

[macardoso]

Be careful with any chemical rust remover even the ones that are supposed to be safe. I lost a couple of gauge blocks by soaking them over night in vapo rust . It destroyed the finish. Shorter amount of time and watching it closely might work. The ding can be carefully removed with a fine stone. It should work just fine by avoiding the rust spot on the side

yeah, I was hoping to not use any chemicals on it. I think flat stones would be the ticket, but it is hard to justify a $200 pair of stones to touch up a $20 gage that can be bought new for $250

 

[RJSakowski]

I scrape rust off with a razor blade or utility knife blade. Once you have removed the bulk of the rust, a little careful polishing will remove any rust above the surface. I second not using any chemical rust remover. That include benign ones like EvapoRust.

 

[Moderatemixed]

You might try looking on Youtube for cleaning rusty chrome. They suggest very fine steel wool and metal polish. That rust
should lift and the superfine steel wool wont remove any material from the surface. I have a magnetic cylinder square and love it. Precision is pretty much “my jam”. I might get a T-Shirt that says just that! Cheers.

Derek


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[Shootymacshootface]

Jeeze, I didn't even know that there was such a thing.

 

[macardoso]

Jeeze, I didn't even know that there was such a thing.

They’re pretty cool. I worked in a metrology/inspection lab for an old job and we had a few. One was 18” tall and weighed probably 60lbs.

They’re a reference surface for comparing squareness and are excellent for use in machine alignment.

 

[macardoso]

You might try looking on Youtube for cleaning rusty chrome. They suggest very fine steel wool and metal polish. That rust
should lift and the superfine steel wool wont remove any material from the surface. I have a magnetic cylinder square and love it. Precision is pretty much “my jam”. I might get a T-Shirt that says just that! Cheers.

Derek


Sent from my iPhone using Tapatalk

God, I’d be really worried about damaging the precision finish. I do not believe it is chromed, only lapped, although I could be wrong in that regard.