Surface plate recoverable?

[lotus_esprit_s1]

This 1939 surface plate has been sat abandoned in corner of workshop for many years - what’s the best way to clean it up? Electrolysis to remove the surface rust?
Obviously I wouldn’t expect it to be calibration quality but thought it may be more useful cleaned up rather than sat doing nothing and potentially binned.

 

[pressbrake1]

Elbow grease

 

[Stupoty]

They are fairly hardy , I would just give it a de-grease and maybe some kitchen scrubber love first.

Stu

 

[brightspark]

cleaned mine up nicely with a coarse scotchpad and wd40

 

[DiyAddict]

I've always been impressed with how old cast iron cleans up. I had an angle plate that sat outside under a downpipe for 20 years. Gave it a go with a wire brush and you could still see the original machining marks. I wouldn't suggest wire brushing in your case though!

After a good de-grease, electrolysis is worth a go, but you need to keep on top of the black/grey gunk that the rust turns into. If you wait too long, it can turn super-hard. I'd stop the current every hour and clean it off with a non-abrasive pad, then resume.

 

[Pete.]

I wouldn't use electrlolysis as it doesn't look rusty, only dirty. Hot water and strong detergent to get all the crud off then wire wool. It actually looks pretty decent under the crap.

 

[Brad93]

You can scrape a plate in by hand even if it has a big low in the middle.

This was my first piece ever scraped.

 

[lotus_esprit_s1]

I started cleaning it up and it is absolutely covered in digs and scrapes - looks like it is only fit for the skip and probably why it was left in the corner and forgotten about!

 

[pressbrake1]

I started cleaning it up and it is absolutely covered in digs and scrapes - looks like it is only fit for the skip and probably why it was left in the corner and forgotten about!

I’ll home it
A hour on the planer, job done

 

[Arc Tourist]

It can be scraped in. I'd be confident that there are a couple of members here who would like to have a surface plate as a project.

 

[daedalusminos]

I hope that foot standing off your bench is due to uneven bench top!

 

[MickeyW]

Unless you want to use it commercially for super precision work it may well be usable despite the digs in the surface. I'd clean up the surface and get a straight edge on it to find out what's what.
How you improve it will depend on your skills and what equipment you have to hand. Scraping is a skilled job and time consuming, plus if you're going to go down that road I'd suggest skimming it first to remove the damage.
We used to have our precision tables (some granite and some iron) lapped and calibrated annually. The guy used another smaller surface plate upturned on the work piece to lap it flat. Most plates wear around the centre.

 

[minimutly]

Stress relieving therapy, can’t fault it. Like bricklaying without having to wash the mixer and tools.

 

[Brad93]

Doesn't matter if it has digs in it. It only has to be a planar surface.

 

[Lewis_RX8]

You can scrape a plate in by hand even if it has a big low in the middle.

This was my first piece ever scraped.

View attachment 323394

What did you use as a reference to check its flatness ? , Another bigger surface table or something

 

[Brad93]

What did you use as a reference to check its flatness ? , Another bigger surface table or something

Yes a 18" x 12"granite surface plate. This is only small, about 14" x 10" or so. Criterion is the brand and it was once Grade A. It could use more work but I haven't had the time. It's flat enough for workshop floor use.

I've got my big 2ftx2ft cast iron surface plate in the workshop too which is seriously flat.

 

[pressbrake1]

It can be scraped in. I'd be confident that there are a couple of members here who would like to have a surface plate as a project.

Anything can be scraped in its wherever you want to

 

[pressbrake1]

Stress relieving therapy, can’t fault it. Like bricklaying without having to wash the mixer and tools.

70 hr weeks of it relieved me of any romantic thoughts about scraping

 

[minimutly]

Bit like ******* really clive - the novelty soon wears off?