Cleaning the blade of a old square

R

reggie_obe

Diamond

Joined

Jul 11, 2004

Location

Reddington, N.J., U.S.A.

• Jan 17, 2005

• #1

What would be the best (and least destructive) method for cleaning the dark oxidation (discoloration, patina?) from the blade of a combination square. I recently bought an old Tumico square and the blade while readable is dark. In addition the square and protractor heads also have some spots on the machined surfaces. How should I clean these up without ruining the machined surfaces? My machinest neighbor once showed me how hydrochloric brightened up to very old scales, but I hesitate to do this.

 

R

reggie_obe

Diamond

Joined

Jul 11, 2004

Location

Reddington, N.J., U.S.A.

• Jan 17, 2005

• #2

What would be the best (and least destructive) method for cleaning the dark oxidation (discoloration, patina?) from the blade of a combination square. I recently bought an old Tumico square and the blade while readable is dark. In addition the square and protractor heads also have some spots on the machined surfaces. How should I clean these up without ruining the machined surfaces? My machinest neighbor once showed me how hydrochloric brightened up to very old scales, but I hesitate to do this.

 

Greg B

Hot Rolled

Joined

Jul 13, 2002

Location

Irvine, CA

• Jan 17, 2005

• #3

Scotch-Brite and WD-40. Done it numerous times. While it won't make it look brand new, it will surely be a great improvement.
Greg B.

 

Greg B

Hot Rolled

Joined

Jul 13, 2002

Location

Irvine, CA

• Jan 17, 2005

• #4

Scotch-Brite and WD-40. Done it numerous times. While it won't make it look brand new, it will surely be a great improvement.
Greg B.

 

Forrest Addy

Diamond

Joined

Dec 20, 2000

Location

Bremerton WA USA

• Jan 17, 2005

• #5

It's a little risky using harsh methods when cleaning a scale with graduations on it. It's easy to blur the crisp edges that make the graduations easy to read. for that reason I strongly reccommend against any conformal like abrasive paper, ScotchBrite, or even wet or dry applied to a flat block. I learned this the hard way trying to restore an heirloom combination set for one of my apprentices. It was readable but the edges were rounded over.

Since then I've cleaned up rusty smutty scales and verniers using a slip stone held flat tot eh surface with a kitchen spray cleaner to keep the swarf in suspension. I went to bright metal taking off 0.002" in some cases and still had clear sharp graduations.

 

Forrest Addy

Diamond

Joined

Dec 20, 2000

Location

Bremerton WA USA

• Jan 17, 2005

• #6

It's a little risky using harsh methods when cleaning a scale with graduations on it. It's easy to blur the crisp edges that make the graduations easy to read. for that reason I strongly reccommend against any conformal like abrasive paper, ScotchBrite, or even wet or dry applied to a flat block. I learned this the hard way trying to restore an heirloom combination set for one of my apprentices. It was readable but the edges were rounded over.

Since then I've cleaned up rusty smutty scales and verniers using a slip stone held flat tot eh surface with a kitchen spray cleaner to keep the swarf in suspension. I went to bright metal taking off 0.002" in some cases and still had clear sharp graduations.

 

tnmgcarbide

Diamond

Joined

Jul 6, 2004

Location

N. GA- 33.992N , -83.72W usa

• Jan 17, 2005

• #7

might try a mild phosphoric acid bath. coke/pepsi/rc/drpepper
overnight would be a start, longer if needed.

 

tnmgcarbide

Diamond

Joined

Jul 6, 2004

Location

N. GA- 33.992N , -83.72W usa

• Jan 17, 2005

• #8

might try a mild phosphoric acid bath. coke/pepsi/rc/drpepper
overnight would be a start, longer if needed.

 

J

j.carlson

Hot Rolled

Joined

Feb 3, 2004

Location

Grand Island, NY USA

• Jan 17, 2005

• #9

Oil and fine steel wool. Will not bring it up as broght as Forrest Addy's method but will inprove readibility.

Jim C.

 

J

j.carlson

Hot Rolled

Joined

Feb 3, 2004

Location

Grand Island, NY USA

• Jan 17, 2005

• #10

Oil and fine steel wool. Will not bring it up as broght as Forrest Addy's method but will inprove readibility.

Jim C.

 

crzypete

Hot Rolled

Joined

Jun 8, 2003

Location

New York State

• Jan 17, 2005

• #11

I lik a product called sand-flex- it's an abrasive suspended in a rubber block available from klingspor- literally a rust eraser. Because the abrasive goes all the way through you can profile it to get into tight spots. I think it available elsewhere- I haven't looked- here's the link I know.

Sand flex

 

crzypete

Hot Rolled

Joined

Jun 8, 2003

Location

New York State

• Jan 17, 2005

• #12

I lik a product called sand-flex- it's an abrasive suspended in a rubber block available from klingspor- literally a rust eraser. Because the abrasive goes all the way through you can profile it to get into tight spots. I think it available elsewhere- I haven't looked- here's the link I know.

Sand flex

 

R

reggie_obe

Diamond

Joined

Jul 11, 2004

Location

Reddington, N.J., U.S.A.

• Jan 17, 2005

• #13

Forest, I am a little confused by all the conflicting replies to my question. You are saying any type of chemical method might make the graduations less readable. Correct? So skip the HCL dip and no Coke or Pepsi. Don't use Scotchbrite or steel wool, because I will loose flatness and round the edge of the rule. You advocate gently stoning the surface. Would a very fine grit Japanese waterstone be okay?

 

R

reggie_obe

Diamond

Joined

Jul 11, 2004

Location

Reddington, N.J., U.S.A.

• Jan 17, 2005

• #14

Forest, I am a little confused by all the conflicting replies to my question. You are saying any type of chemical method might make the graduations less readable. Correct? So skip the HCL dip and no Coke or Pepsi. Don't use Scotchbrite or steel wool, because I will loose flatness and round the edge of the rule. You advocate gently stoning the surface. Would a very fine grit Japanese waterstone be okay?

 

C

carla

Stainless

Joined

Mar 12, 2002

Location

W. Coast, USA

• Jan 17, 2005

• #15

Reggie, I'll concur with Forrest on this one......I've polished our a few old scales, one time and another, and found, exactly as did Forrest, that anything other than a very fine oilstone will radius the sharp edges, and create minor irregularities in the flat surfaces.

A fine Japanese waterstone is probably still too coarse for this purpose. A "Lily White Washita", or equivalent, used with a very light oil, such as "Break-Free" or equivalent, or mil-spec gun oil, or even "WD-40", or kerosene, if you've nothing better, will give you the best chance to clean up your scale nicely.

cheers

Carla

 

C

carla

Stainless

Joined

Mar 12, 2002

Location

W. Coast, USA

• Jan 17, 2005

• #16

Reggie, I'll concur with Forrest on this one......I've polished our a few old scales, one time and another, and found, exactly as did Forrest, that anything other than a very fine oilstone will radius the sharp edges, and create minor irregularities in the flat surfaces.

A fine Japanese waterstone is probably still too coarse for this purpose. A "Lily White Washita", or equivalent, used with a very light oil, such as "Break-Free" or equivalent, or mil-spec gun oil, or even "WD-40", or kerosene, if you've nothing better, will give you the best chance to clean up your scale nicely.

cheers

Carla