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rusty iron - clean up methods?

Russ Tibauls

Plastic
Joined
Feb 11, 2012
Location
ohio
hi all,

i posted this in the Bridgeport/Hardinge section but it may be better here??

anyways... i got a Hardinge TM for scrap price. seems to have been used very little but was left in an unheated/uninsulated closed up shop for 40 yrs.

this is the result. this stuff is giving me fits, all the t-slots are loaded with it.
so far i`ve only been using WD-40 and a wood paint stick.

any suggestions for getting this stuff cleared out? it`s like a hard gritty clay.

thanks for any help and/or suggestions.

i should add that all the protected areas are fine so i don`t want to tear it down. it`s just the table that i`m having the issue with, otherwise i would just try electrolysis.

1331495181.jpg
 
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Taking off the table isn't that hard for a electrolysis bath...but if it must stay on - then scrape out what you can - plug up the T-slots on sides - fill with Evaporust, or vinegar (some add salt), or other (mild) rust reacting fluid - lots of different 'recipes' for such fluids on the internet. Note that I once tried doing that to an large lathe bed using evaporust and little clay damns and leveling the bed and then covering with saran wrap...that didn't work too well and was pretty ugly where saran wrap met metal. Everything rusted needs to be flooded with reacting fluid to come out well
 
Russ,

So, is it old shavings and oil hardened over the years and turned into "hard gritty clay"?

If so, I have cleaned out a similar amalgam using a chisel and gouge (old ones), a scraper and then sandpaper and scotch brite to get down to the normal surface.

After that, perhaps electrolysis, or just a scrubbing with WD-40 and scotch brite?

:cheers:
 
you guys are right.
i should just take the knee and table off and do the electrolysis.

FWIW- it looks like it going to come out nice, there is just a touch of pitting in a couple spots.
whoever used it was very careful. there isn`t any marks i can see.

thanks!

ps. yep- it seems to be chips,dried oil and rust. where it was sitting there was some drips from the roof landing right on the table. it was probably near new condition when it was used last. :(
 
Vinegar yes, salt NO! The chloride ions in salt will start a rusting reaction similar to what road salt does to an automobile - once it starts, you cannot stop it without removing the ions from the steel.

I'd attack this one first with John Oder's "push the rust off with a machinist's scraper" method on the machined surfaces followed by custom-fit tee slot scrapers for the insides of the tee-slots. (You will need tee slot scrapers anyway when you use the mill.)

I'd follow up with EvapoRust or Phosphoric Acid or Citric Acid. Phosphoric is available as "Naval Jelly", which can stick to a vertical surface. Leaves a nice semi-protective coating that would be good inside a tee slot.

Nothing abrasive on any assembled machine with ways.

John Ruth
 
I've used Evaporust for soaking parts in. It might work well if you put it in a spray bottle; but you might need to lay something over the surface to "hold" the Evaporust on the piece since you wouldn't be soaking it. Maybe shop rags or newspaper?
 
I've used Evaporust for soaking parts in. It might work well if you put it in a spray bottle; but you might need to lay something over the surface to "hold" the Evaporust on the piece since you wouldn't be soaking it. Maybe shop rags or newspaper?

In my experience using Evaporust it is better to submerge the parts completely. Otherwise a thin black line forms at the edge of the wet section. This line does not come off during subsequent soakings.

I think the same problem might be had with keeping a wet rag on a surface. The surface where the rag is located will be rust free; the adjacent edges will not, and there will be a black line between them.

These links are informative:

Rusted Parts Pictures

Rotisserie Car

Notice where they use a continuous spray for large parts.
 
Vinegar yes, salt NO! The chloride ions in salt will start a rusting reaction similar to what road salt does to an automobile - once it starts, you cannot stop it without removing the ions from the steel.

Hmm - not sure that's true..I won't post anything I haven't actually tried - too much of that already out there in the internet ether.
I have de-rusted lots of items with both vinegar alone and vinegar + salt solution, and the end result is about the same - with salt perhaps the rust removal is faster, but not much. Both methods require a good washing after or the item with start to rust exposed to atmosphere.
Rust removal with vinegar works quite well and is cheap - but does leave a black residue coating that looks the same as using chelating agents like evaporust if item left too long in evaporust. Not sure what that' black' is - would like to know

Also have tried the paper towel soaked evaporust and previously mentioned evaporust under saran wrap for items to big to submerge -and i agree with FrankR - both methods left harsh black stains and goop at the atmosphere evaporust interface that were more difficult to remove than the rust itself - although I left things sit too long (a day)...and I perhaps with experimentation it could be made to work - but my conclusion having actually tried it - doesn't work very well - even with the saran wrap preventing atmosphere contact - I.e must submerge iron entirely.

BTW - I used 20% vinegar diluted half with water - that is found in the chemicals/'cleaners section of larger stores and not as easy to find as normal 'kitchen' vinegar, which I have never tried. My jugs states "20% acidity Not for consumption or pickling"
 
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