The Best Way to Remove Rust From a Cast-Iron Tool Table
George VondriskaGeorge Vondriska demonstrates the best way to remove rust from a cast-iron tool table.
Unlock Your Woodworking Potential!
Sign up for our newsletter for endless woodworking inspiration! Become a member today and gain access to a world of craftsmanship.
Here's something that I hope never happens to you but I know that shops being shops, humidity being humidity, sometimes these things happen. This is a Cast Iron Band Saw Table that has quite a bit of surface rust on it. So what I wanna do is show you how you can fix this and help prevent this from happening again in the future. Luckily, like I said, it's surface rust. The rust is not pitted into the cast iron so that's good cause it hasn't left any holes behind.
So I think once we get through this whole process you're gonna be surprised at one, how easy it is and two how close we can get this table to its original condition, with a little bit of cleaner and a little bit of elbow grease. I've got a couple of different products here that are gonna help solve this problem. One is a penetrant right off the shelf from a home center or a hardware store. Same stuff you would normally use on a rusty bolt or anything like that, that you're trying to get loose. The other, little bit more woodworking specific.
This is out of a dry lube family of products. This one is a product that will take rust off I hear. So let's do a little experiment here. We'll do a little bit on one side and then the other product on the other side. The key is make your life easy.
Get the stuff on there, give it a chance to sit and work so that you don't have to work so hard. Got a good coating of that on there. Now let's run this on this side. while this stuff is cooking a little bit, get yourself some Scotch-Brite or some sandpaper. Basically what we're gonna do here is wet sand this cast iron in order to get the rust off.
So like I said, before the wet sanding begins, let's give this stuff a couple of minutes to do its thing. Then we'll come back and see what an abrasive does to start cleaning that rust off. This has had about 10 minutes to sit and I did rub a corner down here just to see where it was at and know that we could come back and get started. So let's take the Scotch-Brite pad to this. See what happens.
Now here's the deal, Scotch-Brite is a great choice for this cause it's abrasive, but it's not real abrasive. If you find that you have problem spots. I'm suspecting that right through here, the Scotch-Brite might not quite be enough to clean that up. Then you can go to a sandpaper. I'll start with probably a 220-grit.
See how that goes. You can tell... You can see just from the orange I'm producing here that a lot of rust is coming off. Let's rub on this side a little bit. See how we did over here.
At this point it's just an elbow grease thing. You gotta take the time to abrade the surface and undo what water and nature did to your cast iron. All right, let me do a little cleanup with paper towel just so you can see where I'm at. Got a ways to go yet. I'm gonna switch to sandpaper, the Scotch-Brite's not quite gonna be enough here.
It's better. We've opened up a lot 'a cast iron here that we couldn't see before. But I'm going to apply some more Schmutz on there. We'll do the same thing, this stuff on this side, this product over on this side, but I'm gonna go to that 220-grit sandpaper, little bit more abrasive. It's gonna do the work a little bit faster for us.
Let's see where we're at now. Ah much better than it was. Big difference going to that sandpaper 'cause it is more abrasive than the Scotch-Brite. I got a little ways to go yet. Some more of that black is gonna come off.
So I'm gonna keep going. I'm gonna get some more of the liquid on here. I'm gonna let it do its thing. Keep working with the sandpaper and get this top cleaner yet than it is right now. Here's where I'm at.
I've got about 15 minutes of elbow grease time in this baby. And I've progressed through the 220-grit sandpaper. I'm up to a 280-grit piece here, wrapping it up. And I did wipe it and then reapply the liquid twice in the time I was rubbing it. Now, what I wanna do is get this cleaned off.
So I'm gonna use a clean paper towel, little bit of Mineral Spirits on it. That's gonna help cut through this. There now you can see the work that the abrasive and the rust remover did for us. Like I mentioned earlier the good news is the top isn't pitted. It was really rusty but there are no holes left behind by that rust.
It was all just surface rust. So one of the lessons out of this is when you're tool shopping if you find some used tool that wasn't very well taken care of and you see that surface rust on it now you know that it can be cleaned up. Good question would be why all that hand sanding why not take a power sander of this? I just don't like the chance that with a power sander I'm gonna take too much material off. I'd rather hand sand the whole thing.
Watch it real close. Make sure that I'm just taking the rust off. I'm not really removing any cast iron. So this did a real nice job 'a cleaning this up. What we should look at next is what steps can we take so that this doesn't happen again.
When it comes to cleaning up that top it's a really good idea to wet sand it like I did, it could be tempting to just go straight to sandpaper but the wet sanding really eliminates a lot of the elbow grease that you'd have to do in the absence of using those rust removers. Now, what we wanna do is make sure this never happens again. So a couple solutions here, Carnauba Based Paste Wax is one solution. This is the same stuff that somebody might use on a wooden floor, a wooden piece of furniture. The key is like always, no silicone in the product because we don't want that to migrate into your material.
I'm gonna go back because I'm way too lazy to use paste wax and rub it out to my tabletop sealer, spritz that on just like I've done on all my tools, rub it out. Now a couple of reminders this particular tabletop actually got rained on. There was a leak in a roof and it dripped right on the tabletop. That's how it got so bad. Hopefully that'll never happen in your shop but just humidity in the air is enough to cause rust on cast iron.
So the sealer is really going to help prevent that. Another thing when you're walking into your shop with a soda can, or a coffee cup, don't ever set those down on your cast, iron tabletops, cause they're going to sweat and that's going to drip down onto the cast iron and it's going to leave a little ring on the tabletop. Well, this did a great job of cleaning up cast iron and we've cleaned up on a lot of ideas about setting up and maintaining tools in your shop. Table saw, joiner, bandsaw, planers lot of great information to help make sure that your tools are set up correctly and that they're going to keep running and running and running. So you get a lifetime, a good, hard work out of the tools in your shop.
Happy woodworking and have fun.
Here's a tip. As a woodworker for over 50 years I've come to the conclusion that there is no reason for the cast iron to be raw for "Woodworking". I paint all my cast iron surface like a car. If a old machine is pitted i use Bondo plastic filler and paint. Wood slides better and there is no maintenance. Metalworking machines a different story. Keep them raw.
olive oil works good also
I use CRC 3-36 and spray the entire surface first. I then load a gray 3M Scotch-Brite pad (rectangular...I forget the product number for the gray pads) into a quarter sheet vibrating sander (NOT a random orbital sander). I go back and forth on the table, following the "grain" of the metal top (if there is such a thing) for a few minutes until a black "slurry" forms. I then wipe this off with towels and denatured alcohol and then give the entire top a few coats of paste wax. Works great!
I've done this on several cast iron table saw table tops. I just use car wax and a wire brush on a drill. Works wonders with no effort and only a couple of minutes.
I use crud cutter rust remover and the gel spray it down let it sit 15 minutes wipe it off it's almost spotless. I also soak my tools in muric acid and I’ve also used miric acid on my old rust vise but do it where you have good ventilation or outside with a mask or respirator on.
I use a grill brick and oil or WD40, then use a good paste wax and I am good all winter long, this makes the table top like new. Thanks and you shows are great
WD-40 isn't bad either but white vinegar is good too. It does have to soak for a while.
I clean off rust the same way you do--with penetrating spray--but I use a "new improved" version. After letting the spray sit for 15 minutes, I sprinkle on Bar Keepers Friend. It's like the old timey Dutch Cleanser. It's intended to clean and polish stainless steel. I sprinkle it on the spray and mix them up until I get a slurry. Usually a scotch Brite pad on a sanding block finishes off the rust removal. I seal it with furniture wax. Top can actually get a little shiny.
George, The chemicals you used for this video are good, WD-40 is also, but the abrasive process you used could leave flatness imperfections on the table surface. I was a machinist then engineer for many years and had to clean up many a rusty or banged up milling machine table. A clean, flat 220 grit, or higher sharpening stone is a much better approach. It's also considerably faster than using the scotch bright.
We hVe been told if there is any difference between the two lubricants that he used for wet sanding. Did he find one better than the other?