Removing Rust from Cast Iron Table Top

[Fastnhappy]

HOW???

Someone at HD said coke and a wirebrush which I've been using with some success, but is there a better way? I just bought a Ridgid TS 3650 and it has some rust on top of the table. Looking for the best way to get it performing as well as it can. The rust has bubbled up a bit, so it leave the table slightly uneven.

any help would be great!

[thrytis]

I used some of the Rust Free (by the same guys that make Boeshield T-9) and wasn't impressed. It seemed to do the job, but you could tell afterwards where it was sprayed. My suggestion is to start with some green scotch-brite pads and lots of WD40. It does a pretty good job on light rust to leave a smooth finish. You can even put the scotch-brite pad on the bottom of a hook and loop sander to give it a little more omph. If it is heavy rust you probably need something more though.

[kramer katt]

evapo rust

this is a product highly regarded at OWWM.org for iron rust removal
It is sold in quarts and gallons for about $10 and $20
I found some at good old Harbor Freight and used a 20 percent coupon
Not as toxic/obnonxious as some removers and can be reused until it its powers are gone
kk
BTW
works best if you can soak the item so better for smaller parts unless you have a large enough tub for the CI top

[cabinetman]

On a badly rusted top, I use 120x silicone carbide sandpaper (wet-or-dry) folded on a flat block of wood, used wet with WD-40. Afterward, a good wipe down with lacquer thinner (acetone wood be better). Then, treat with Topcote. I don't use wax on surfaces that come in contact with wood.
.

[conwaygolfer]

Why not a belt sander with light pressure applied? Let the tool do the work. I am all for modern "elbow grease".

Conwaygolfer

[gary]

Spray the surface with WD40 and use a random orbit sander with a scotch-brite pad on it. The hook and loop sanders hold the pads well. Wipe surface and repeat until clean.

After it's done and dry. Use Boeshield T9 followed by a coating of wax.

Scotch brite pads come on different sizes. The larger green ones work great and fit the sander.

This technique works great.

[phrog]

On a badly rusted top, I use 120x silicone carbide sandpaper (wet-or-dry) folded on a flat block of wood, used wet with WD-40. Afterward, a good wipe down with lacquer thinner (acetone wood be better). Then, treat with Topcote. I don't use wax on surfaces that come in contact with wood.
.

Cabinetman,
Why don't you use wax? Is it because it impedes further finishing of the wood? I've read that a lot of people use Johnson's paste wax on cast iron surfaces and just wondered your reasoning. Thanks.
Richard

[Uncle Cracker]

Cabinetman,
Why don't you use wax? Is it because it impedes further finishing of the wood?

Yup, some waxes act like silicone, and will keep a stain from soaking in, or a finish from adhering. Usually just leaves blotches, and the more you try to match them up, the worse it usually looks. Other waxes are OK, but I usually don't risk it. There are products that are made specifically for this purpose. I do use wax for metal-to-metal surfaces (such as lathe bedways) since there will be no contact with finished work (I hope)...

[cabinetman]

Yup, some waxes act like silicone, and will keep a stain from soaking in, or a finish from adhering. Usually just leaves blotches, and the more you try to match them up, the worse it usually looks. Other waxes are OK, but I usually don't risk it. There are products that are made specifically for this purpose. I do use wax for metal-to-metal surfaces (such as lathe bedways) since there will be no contact with finished work (I hope)...

Not only do some waxes act like silicone, but have it as an ingredient. Others may have similar ingredients such as PTFE (Teflon). Contamination from waxes or wax like substances on machine tops like a table saw can go a long way in a shop. A simple scenario would be a piece of wood gets cut and comes in direct contact with the substance. Airborne debris from that process becomes ambient. Further machining such as planing, jointing, or sanding disperse dust into the air, which some will float for a while and land just about anywhere.

It's resting place could be the next item to be finished, or some area that will further cause contamination. This is a real issue, if you do any degree of finishing in the shop.
.

[pelligrini]

I used some fine grit discs in my old ROS on low speed when I was fixing up a badly rusted jointer bed. Steel wool and Boeshield T-9 rust free was taking a long time. The sander made quick work of it.

The Sandflex blocks are really nice for smaller areas. A lot of woodworking stores sell them. I wish I knew about them when I working on that jointer the first time.

http://www.bt3central.com/showthread...andflex&page=2

[goohs]

I purchased an old delta with the steel top all rusted., Almost solid rust!! I wet the surface with warm water then applied naval jelly and followed the instructions. The top took about 1 hour to to totally clear and it looks like new. Over the last year I have only had to treat a few spots with naval jelly once. I do keep a wax coat on the table ( make sure no silicon) and have never had any problem with wood finishing, of course I do use minwax wood prep prior to staining and that might be an influence.

[JSUPreston]

I purchased an old delta with the steel top all rusted., Almost solid rust!! I wet the surface with warm water then applied naval jelly and followed the instructions. The top took about 1 hour to to totally clear and it looks like new. Over the last year I have only had to treat a few spots with naval jelly once. I do keep a wax coat on the table ( make sure no silicon) and have never had any problem with wood finishing, of course I do use minwax wood prep prior to staining and that might be an influence.

I admit, I've had belly button lint before...but never jelly.

Personally, I've used WD40 and something like 320 grit on a ROS. I've got some staining on the surface of my saw (leaky roof), but the sanding knocked the surface down flush. I then coated the surface with some surface wax I bought from Rockler years ago. Seems to work for me.

[Black wallnut]

This thread is only 4 years old..........

[jdon]

This thread is only 4 years old..........

Before it's reinterred, has anyone tried electrolysis on a CI table top?

I dimly recall reading about using a towel soaked in a baking soda solution sandwiched between the table top and a steel plate (as the anode). It should be non-destructive and not too labor intensive.

[Pappy]

Before it's reinterred, has anyone tried electrolysis on a CI table top?

I dimly recall reading about using a towel soaked in a baking soda solution sandwiched between the table top and a steel plate (as the anode). It should be non-destructive and not too labor intensive.

I did that on my Rockwell jointer. After the electrolysis, I buffed it with a fine synthetic pad and DuPont Rubbing Compound then affine pad with DuPont Polishing Compound.