Caring for cast iron

[Beechwood Chip]

It's time for me to deal with some minor rusting and general cleanup of my cast iron.  My plan is

• WD40 + green Scotch Brite + ROS
• Johnson's paste wax + buffer

Questions:

What's the optimal buffer tool and pad?  I have a random orbit sander and an angle grinder.

Is there any benefit to spraying topcote or CRC 3-36 in addition to the paste wax?

Is it worth hitting the rust spots with Naval Jelly beforehand?  The instructions say to rinse with water, and the idea of pouring water on my cast iron makes me wince.  But I guess if I'm doing a complete scrub and wax afterwards, it's OK.

Any other advice?

 

[rodger.]

I normally go wd40 with 0000 steel wool.  Then a wipe down, and a layer of topcote.  Then wipe off, and apply paste wax.  I don't really see the need for the sander, but to each his own.

[Tpt life]

I have been noodling. How do you deal with liquids and ROS? Is there some way to allow air circulation without fear of sucking oil through the dust collection?

[Coop]

I have been noodling. How do you deal with liquids and ROS? Is there some way to allow air circulation without fear of sucking oil through the dust collection?

I cut a piece of solid 120 wet and dry sandpaper to fit my ros and it worked really well.

[Tom King]

I keep a wire cup wheel on a 15 amp sidegrinder and some Scotchbrite pads to use Jack Forsberg's method.  I can make the rustiest table saw top shine "like the top of the Chrysler Building" in less than a minute:

Jack uses a small grinder, but I had an old B&D that belonged to my Dad that I didn't have any other use for.  The big grinder makes much quicker work out of it, and keeps the wire brush farther away from clothing.

I haven't used anything but CRC 3.36 since I first found out about it.  It's not permanent, but does last a long time.

I'll see if I can find Jack's video.  I found it, but copying and pasting inserted the wrong video of his, and I can't figure out how to delete it.

Copy and paste this into the youtube search box:     Keeping cast iron tops clean and rust free the easy way

Another way is if you click on the 1/100 in the upper left, scroll down to video 34, that's it.

I don't bother to cut the Scotchbrite pad to fit the round wire cup.  I just stick the whole thing on, and the flying corners don't bother a thing.

 

 

 

 

 

 

[Jim DaddyO]

For the slight surface rust I deal with I wet sand with 400 grt and use wd-40 as a lubricant.  I clean it off after with naptha, and then apply paste wax (Johnsons, tre-wax, any paste wax without silicone) and rub it out with a clean rag after it dries.

[estesbubba]

Your first step is good but skip the paste wax and use CRC 3-36 instead. A nice thin coat and it's ready to use the next day. 

[Beechwood Chip]

Thanks for all the tips!  I knew it'd be smarter to ask than to guess.

[TerryMcK]

It sounds like you have a lot of rust if you are using a ROS. I normally use a hand sanding block with wet and dry. You can use WD as a lube without fear of it sucking into the mechanism of a ROS/dust collector ( not that it is a problem). But the benefit of hand sanding is that it is great for localized rust spots.

 

I then use Boeshield followed by a layer of paste wax.

[Jim DaddyO]

Hmmmm.  Fall is here and I have things that are way overdue, like my little jointer that has been sitting for a while.  Perhaps I ought to do a video of how I go about it.  It has a bit of rust developing on it.  Would that help?

[Beechwood Chip]

Wouldn't hurt!  Thanks!

 

[wtnhighlander]

If you really don't want to battle the rust, don't remove it all. Oxidation of the iron forms a somewhat protective layer, that slows or inhibits further formation if rust. I bought my current saw 3 years ago, used, and it had a good layer of fine rust on the top, no scales or pitting. I spent some time hand sanding with WD-40 to remove anything loose, and make it smooth, but there is still a layer of rust-brown "stain" over the whole surface. After cleaning up the WD-40, I applied a good coat of Johnson's paste wax, and haven't touched it since. My saw lives in my unheated, uninsulated garage, where temperatures range from 15* to 115*F, and humidity stays in the 80-90% range all summer. No rust.

[Jim DaddyO]

I will try to get it up before the end of the weekend.  I will start a new thread for it.

Wouldn't hurt!  Thanks!

 

[Lee Bussy]

Just in case people have not found the video:

Here's the 3-36 @ Grainger:  http://www.grainger.com/product/CRC-Multipurpose-Lubricant-2F141?opr=APPD&pbi=4JB28

 

[Beechwood Chip]

Found it, bought the CRC, wd-40, Scotch-Brite pads, 0000 steel wool, and wire cup for my grinder.

Thanks, everyone, fort the help!

--- Chip

[Tom Cancelleri]

I use maroon scotchbrite, and crc to clean any rust spots. The key to cleaning rust is to prevent it from happening. Get it nice and rust free, wipe down with mineral spirits, then crc wiped back with a paper towel, it should look nice and shiny. Let it sit for a few hours, then buff the iron with a dry rag and apply 2 or 3 coats of renaissance wax, or silicone free paste wax Sent from my 831C using Tapatalk

[Sac]

SO when you guys talk about rust spots, what kind rust spots are you talking about?  I have a few spots on my stuff from when I just moved.  The gorillas that moved my tools dripped sweat on them in spots and I want it off.  Right when I noticed it I hit it with WD and a green scotchbrite, but it didn't get it off.  It cleaned the big stuff off, but still left that rust stain.  Will the grinder/wheel/scotchbite pad take that off?  Thanks.

[Lee Bussy]

SO when you guys talk about rust spots, what kind rust spots are you talking about?  I have a few spots on my stuff from when I just moved.  The gorillas that moved my tools dripped sweat on them in spots and I want it off.  Right when I noticed it I hit it with WD and a green scotchbrite, but it didn't get it off.  It cleaned the big stuff off, but still left that rust stain.  Will the grinder/wheel/scotchbite pad take that off?  Thanks.

Ultimately, removing rust is an abrasive process.  So long as there is metal left underneath, application of an abrasive will remove it.  This is the same as sanding wood and prepping it.  You can use fine sandpaper if the wood is already smooth, but if there are deeper scratches/gouges, the fine sandpaper will never touch it/take forever.  

Cast iron also has some porosity so if you unluckily have some where the sweat landed, it's deeper than you may think.  If it's really deep you may have to use a more aggressive abrasive.  I've had similar issues in another pastime and had to take the piece to a machine shop to re-mill the surface to get a clean start.  Alternatively one can use some phosphoric acid (naval jelly) to transform the rust into iron phosphate which is black-ish in color.  You will still see the spots but arrests the rust's growth potential and oiling subsequently will help.  It's all a matter of how much metal you are willing to take off in one spot before it's too much.

Specific to your question - the green scotchbrite is really not an abrasive.  It's just hard-ish plastic.  The other ones guys are talking about are actually impregnated with an abrasive and will chew through metal as well as rust.  I was able to find those recently when at a local Sherwin Williams paint store.  This is what they are talking about (link to Amazon):

 

Hope that helps a little.  Green pads may eventually do something, but it's more likely to wear off your fingers before it starts to wear the metal.

[Sac]

Thanks LBussy. That is actually very helpful. I will have to try and find some of those pads. I am not sure how deep it got, I noticed it the same day it happened and cleaned it up pretty quickly. It's not like it stayed on there for an extended period of time. I have lots of cleaning and took setup to get done before I get to making sawdust again. I will have to make time for this too. Thanks again. 

[davestanton]

I use Festool's Vlies 800 pads on the rotex. Have a look here. https://youtu.be/_o1sGrcou6A