'Stained' cast iron

[stuartpaul]

In the process of setting up the new W650 purchased at Yandles and after having cleaned the usual protective gunk off the top noticed that the table appeared to be 'stained'.

A good rub with webrax and white spirit removes the heavier deposits but does leave this horrible stained look (the brown stains aren't rust!).

Anyone come across this before (I certainly haven't) and if so how do you get rid?

Charnwood haven't exactly been speedy in replying but waiting to see what they say.

 

[wobblycogs]

I had something that looked very similar on the tables of my P/T when it arrived. I assumed that somewhere along the lines plastic was placed over the top of the tables with grease or similar to stop the tables going rusty (probably on the way over from China). I guessed plastic because, like in the picture you show, the marks look like the imprint of crinkled paper. Anyway, I just rubbed the tables down with a bit of wet and dry and they came up a treat.

 

[ondablade]

It's possible it's another form of iron oxide (i.e. a corrosion product of some sort), there's loads of different types that form in different circumstances and in the presence of differing compounds.

I did a fair bit of digging to try to come up with a method that'll bring up a bright machined metal finish again, and (b) not remove metal or cause other problems. The bad news is that there doesn't seem to be any 100% performing DIY solution out there. There's a few methods you see about:

1. Abrasive pads with WD40 (trouble is that staining often gets down into the pores on CI)

2. Bead or other mild blasting. (required stripping off of parts)

3. Etching with dilute phosphoric or hydrochloric acid. (don't know what sort of surfaceit delivers, too much removes material and can cause brittleness)

Some of the automotive paint companies make what is possibly a mild acid based solution for removing 'flash' rusting before painting - it might be worth some cautious experimenting with.

Waxing seems to be the preferred option to both protect and make surfaces slick..

 

[NetBlindPaul]

Solvent to clean out the "pores", clean down, then look at Oxalic Acid, though that involves washing of with water IIRC, so you would then need to chase this out and oil/wax.
AT YOUR OWN RISK though, sorry guys!

Once up and running try a proprieraty anti slip coating expensive but in liquid form NOT aerosol it goes a very long way and is silicon free for the painters out there, it will "fill" the pores of the CI & prevent such an recurrance.

 

[stuartpaul]

I had something that looked very similar on the tables of my P/T when it arrived. I assumed that somewhere along the lines plastic was placed over the top of the tables with grease or similar to stop the tables going rusty (probably on the way over from China). I guessed plastic because, like in the picture you show, the marks look like the imprint of crinkled paper. Anyway, I just rubbed the tables down with a bit of wet and dry and they came up a treat.

Pretty certain that's what's happened here.

I don't really want to resort to chemicals to remove it as it does just look superficial. I guess some more elbow grease required!

Disappointed that a new machine comes in this sort of condition. Charnwood not very forthcoming on this or a couple of other issues. Starting to wish I'd gone down the Axminster route as you kind of know they'd deal with it efficiently.

 

[Dodge]

Charnwood not very forthcoming on this or a couple of other issues.

Charnwoods customer service/guarantee back up is atrocious! - I have had a couple of experiences of them in the past and two Charnwood machines failed within days of purchase but took months to sort out.

Basically I would not touch anything Charnwood again unliess I had a bargepole made from Unicorn Tusk with Hens teeth inlay!

Rog

 

[wobblycogs]

My P/T came from Axminster as an "almost new return" so clearly they shipped the table with marks on it both new and second hand. I think if I'd paid full price I'd have been a bit miffed that I had to rub up the tables but as I got a pretty good deal I was happy enough to break out the elbow grease.

 

[stuartpaul]

Charnwood not very forthcoming on this or a couple of other issues.

Charnwoods customer service/guarantee back up is atrocious! - I have had a couple of experiences of them in the past and two Charnwood machines failed within days of purchase but took months to sort out.

Basically I would not touch anything Charnwood again unliess I had a bargepole made from Unicorn Tusk with Hens teeth inlay!

Rog

Just what I needed to know right now :shock:

The only upside of that is having purchased it at Yandles I can (I think!) go back to them as the purchase 'contract' is with them.

 

[Steve Peacock]

Hi,

As far as I understand it, machines are often shipped or stored using a vapour phase corrosion inhibitor. It's an amine compound that forms a protective film on metallic surfaces and stops the oxygen from rusting them.

The vapour phase inhibitor usually comes in the form of brown paper that is impregnated with the chemical. That may be why your table looks as if it was in contact with something wet and crumpled (like paper or plastic).

I'm not sure why it would stain, though...

Cheers
Steve

 

[ondablade]

Another issue is that cast iron varies quite a bit as regards corrosion resistance depending on the composition - the more resistant versions it seems have some of the usual chrome and the like in there....