Thread: Rusty Cast Iron Table Saw

If it's only surface rust, a fine wet & dry abrasive paper, say 240 or 320 on a flat sanding block, lubricated with kero or WD40 will do the trick.
Wipe it dry and apply wax, and polish it out. That will seal the surface after several applications and stop a recurrence. It will also make it easier to use, as the timber will slide easier.
If it is heavier rust, the surface may well be pitted which you can't do much about except clean up what's left of the table with a coarser grit, say 120, and use a ROS to save the elbow grease. Then wax as above.

If it is severely pitted you can fill the pits with metal filled epoxy and sand to a smooth finish. This works surprisingly well and lasts for decades.

As well as protection the wax makes for a very smooth finish to move wood around on, just don't use too much of it or it may affect finished.

For surface rust, I have found the best way is to buy some 3M Scotchbrite scouring pads, heavy duty, from your local supermarket and spray the table with WD40 and then use the pads to remove the rust. Requires elbow grease, and lots of it, but I found that a cheap Ozito 1/3 orbital sheet sander with a velcro attaching base will take the pad nicely, and that is far easier than rubbing the rust off by hand - so quick and easy. Do it a few times, wiping the the oily rust off by rag, then respraying and rubbing again.

Next trick is to remove the oily residue after wiping the cast iron clean. Some use kero, others metho and others turps, but I am not sure. Can anyone advise on this please? I have previously used metho, and today used kero , which the label says is also good for removing wax.

The final trick is to use a wax finish to prevent, or rather minimise rust because you will never stop it unless you do the above regularly.

Some use Superglide from Carbatec, some use Canuba or some Traditional Wax from Ubeaut, and others in high humidity in the tropics use Becketts Bronze / Ferrous microcrystalline wax polish. I have tried the first two without much satisfaction, so am now trying the Becketts. Whatever you choose, make sure it does not contain silicone, as this will ruin the finish of your timber

Hope this helps. This is best for smooth unpitted surfaces.

Thanks for the comments and suggestions. It's good to know it's a common occurrence, as I was starting to worried I had brought a poor quality table saw because of it.

Beckitt's wax is made in WA

I've been through numerous fixes for rusty cast iron table saw tops and have found Evapo-Rust to be hands down the best solution. It's quick, easy and clean-up is straight forward and, environmental and health hazard free. You can read all the details on how it works on the link provided.

Using a brush I apply the liquid directly to the surface. I usually pour some onto the table in small pools so I'm not putting the brush back in the container. I then wait 10-15mins and wipe the excess off with several paper towels. Re-apply and wipe off until clean. If the rust is on the heavy side you may want to use some fine steel wool, or perhaps a kitchen scotch pad, I'd not use anything too abrasive though. Use the wool with the liquid on the table, not dry. If left to dry without wiping down the surface will be sticky, reapply some liquid, wait some minutes and use a scotch pad or the like. Afterwards I dab some solution on a paper towel and wipe the table down without rinsing off. Leave it to dry and it'll form a protective surface for a couple weeks.

When I'm not using my TS I cover the table with an old sheet. I find keeping a cover on maintains the surface for much longer than without. Also, keep wiping the surface down with neat solution on a paper towel every couple weeks.

The only down side is the slight mess it might make from drips, etc. If you're careful though these will be minimal. You could always put some old rags or towels around the base to catch the drips.

Easiest solution ever IMO. It's also great for any rusty items such as screws, tools, etc.

The previous posts should have given you enough info to get you back on track and should allow you to get your saw back to normal bright and shiny condition.
Others have advised me that anything settling on the surface will attract moisture (dust/sawdust etc) and then cause rust, so the best way to keep shiny is to keep it covered. I also use wax regularly and buff it off so it doesn't stain jobs.

I use a large cloth to cover my saw and all my machine tables. It also keeps the gecko's off, they have a habit of pi#$%g on cast iron and the acid pits cast iron overnight.

Avoid placing any moisture generating items on your tabletops, leave a piece of timber on a cast iron table overnight to see how much moisture that holds. Many a woodie has found out the hard way how dry their timber really is.

Rust, It's a never ending story in the tropics,

Cheers, Ian

Thanks for the suggestions everyone. I started sanding it with some 400 grit sandpaper and kero in the end. Which wax is good to apply to the surface and where can I buy it? I'm in Perth, WA if that helps. Prefer something that won't taint any wood I cut if that's possible?

Further to the posts of Gareth R and Nanigai I have found that an old blanket works better than a sheet or other cloth. Probably because the blanket is thicker and repels dampness better and may keep any warmth in.

Safari

Thanks Safari, is a blanket enough to prevent rust, or is that on top of using wax?

Johnsons floor wax is all you need, any supermarket will stock it. You can also use any other paste wax you can find. Just buff it all off after applying an even coat. even though you remove it by buffing there is always some left to protect the surface, just like on a car. Don't use any product containing silicone as it will cause finishing problems if transferred to you job.
Cheers, Ian

I use Ubeaut Traditional Wax, also use it on the bandsaw, thicknesser and jointer etc. Does a great job.

In addition, I place a sheet of 18mm MDF on the tablesaw (after winding the blade down), as well as keeping off any moisture etc, it serves as a great work surface when the table saw is not in use.

I use lino offcuts for all my cast iron tops

stops the moisture and makes a good surface to put stuff on

I also apply inox lanox when I remember to each top

As previously posted I apply some Evaporust with a paper towel and leave to dry. I then cover the saw with an old sheet or more recently a thick thermally backed curtain. I find the curtain does a better job than the sheet. The cover goes on the table with the guard still in place so the cover does not sit directly on the cast iron.

Alternatively you could apply any reasonable furniture wax, leave to dry and cover. I'd recommend doing both, says he who has not covered his TS in the last couple couple of weeks!

The laminate and MDF also sound like a reasonable idea as it would give protection plus a surface to work on.