Removing Pitting from Cast Iron Surface

[Chems]

I have a cast iron planer and it has seen better days. The surface is heavily rusted (which comes off easily) but there is some pitting around the tables. I've been working on it with all sorts of kits, ROS, and diamond stones, whetstones everything I can think of to remove the material.

Whats the best suggestion for removing material from such a large area? I'm thinking it may be best to buy a Belt sanders and just work through the grades?

 

[Shakespeare]

Hiya Chems,

Have you thought of taking it to vehicle engine restorer. They quite often have to 'skim' a cylinder head, so why not a plane. Just a thought.

Baz

 

[Smudger]

I've not yet taken advantage of it, but I believe it is a service Ray Iles offers.

 

[JonnyD]

I would probably just live with it if it doesnt affect the performance. Removing more metal could make the tables inaacurate.

jon

 

[Chems]

I think I will keep working at it with the sand paper for the time being. I dont think its possible really to remove enough material with this method to make the tables in accurate, I've been running my straight edge down the tables and they are still 100% flat.

 

[wizer]

grrr went out to the workshop this morning to find rust spots on the TS. I think it must come from saw dust, there aren't any other sources of moisture. Luckily a few swipes with 600grit abranet saw them off. I'll be re-waxing it tomorrow.

 

[dickm]

Don't think it would be a good idea to skim it enough to remove all the pitting, unless it is very shallow. There'd be quite a chance of the casting distorting afterwards as the stresses change. If it's only cosmetic, then patience and emery paper might do it. Though an engineer's scraper might be quicker.
Or just live with it as a bit of battle scarring and keep up the waxing?

 

[Chems]

I think its fairly shallow. The machine has laid un-used since 2005 its only really on one table. It is cosmetic but I do want the tables to be nice and flat all over.

 

[wizer]

but I do want the tables to be nice and flat all over.

In which case, steer clear of scrubbing the top with abrasives. If it don't come off with a few light swipes, then leave it be!

 

[Racers]

Hi,

You might find the pits keep going rusty this has happened on several planes of mine, the only way I have found of stoping it was to put super glue in them. I tried epoxy but they still rusted, I thing if you super glue them then epoxyed them that would work.


Pete

 

[OPJ]

If both tables are still registering as straight and true against your straight edge then I would just leave it, it's never easy to tell just how deep any pitting can be! White spirit's a good lubricant for cleaning off all sorts of gunk. Apply a coat of wax or two afterwards and you shouldn't have many problems.

Is this the 6" Axminster machine you've just bought? I assume you went for the second hand one on eBay...? (Any chance of som photo's??? :wink

 

[Chems]

It is that one indeed. Heres a photo of it from ebay:

It is all stripped down to parts at the moment and taking its first coat of paint. The rust isn't to bad at all, except on the cutter block. I can't get it off and I can't remove any material incase I ruin the balance of the block. It may be a case of buying a new one. Other than that everything else is in A1 condition. Its barely been used, not a single spec of dust inside.

I'm getting a euro style blade guard from Axminster, £28 instead of the American style one this Mk1 machine has. Its defiantly the bargain of the century, £150 for this, so far spent £20 on petrol collecting it plus another £8 on paint. Probably will spend another bit on paint as well as some replacement parts.

The only other pictures I have at the moment are the ones I took as I was disassembling to make sure I know where everything goes:

Its really easy to take apart, and hopefully easy to put back together as well. I will get a picture of the painting thats going on later today.

 

[dickm]

If the rust pits keep rusting (so to speak) it sounds as if your shop must be damp enough for the pits to suck some water out of the air and carry on the reaction. Might be worth giving the whole thing a good scrub with Jenolite or similar phosphating agent, scrubbed well into the pits with a wire brush until all the rust goes black.
Vague memories of O-level chemistry say that once rust starts, it is almost self sustaining even without damp, so you need to kill all the rust somehow. Then regular waxing ought to keep it OK.

 

[Chems]

Had a look today and you know when you get a bit job specific you see the tiny imperfections, well it looked fine today. Do the other table to the same level and the fence and it will be a fantastic machine!

 

[TheTiddles]

Pitting is exactly as it sounds, you get a localised corrosion reaction which burrows down into the iron. The good thing is that it is contained and removes small areas of material that won't afftect your flat tables till it gets really, really bad, the downer is that it will keep occuring at these pitting sites in preference to anywhere else, however, keep it covered and protected and it will stop dead, all you will be left with is a gentle 'patina' or as I call it 'crap all over the surface'

Removing material is a bad idea beyond polishing, the look of that level of corrosion suggests it's not bad at all and should clean up lovely... pictures please!

Aidan