Rust Removal for Cast Iron TS

[Bill Borchers]

Hi,
I have a cast iron TS that has some mild rust. I have done some searching through the posts and have decided on a T9 and wax combo to prevent rust, but how do I remove it?
I like the idea of using my ROS and some Scotch Brite pads...but
1.) I haven't found round scotch brite pads...do you just cut them?
2.) How do they stay attached to the ROS?
3.) Do you use WD-40 with it and won't it get sucked up into my ROS?
3.) Is it better to use 220 grit dry sandpaper?
Any advice would be appreciated.
Thanks,
Bill

[Russ Filtz]

If it's not too much rust, I would forgo the ROS and just use elbow grease with the scotchbrite pads. I would also forgo the WD40 and use mineral spirits. The 220 is too rough. I would use 400 or 600 wet/dry if using sandpaper, then go up through the grits to whatever shine you like, 800, 1000, 1500, or 2000. Clean all the muck up with more spirits or DNA and then treat with the T-9.

[Daniel Dadourian]

I have a bandsaw that I successfully resuscitated recently using the Boeshield "Rust Free" product with great success. I immediately applied T9 afterward.

I used those sponges that have green Scotch Brite on one side. The sponge part is soft when first removed from the package. But it became rock hard when dry after a few uses. It transmitted the action of the 5" ROS fairly well... using very fine grit sandpaper. Once the sponge started to get wet, or the sander took its toll, I swapped out for another. Hope this helps.

[Brian Weick]

a wire wound Wheel brush ~ tight looped will cut your time down "considerably" ,attach it to a grinding wheel ~ use some protective glasses and some good leather gloves and a good breathing apparatus ~ not the nuisance masks, those do absolutely squat, and watch that rust come off ~ like cutting butter with a hot knife. it will not alter the parts and give you a nice clean surface in a very short period of time, and if you really want it to shine , get a good metal buffing rouge and a buffing wheel ~ it will look like chrome if you spend enough time on it~ I wouldn't use the rouge on the table bed, but the control wheels and the like you can do.
good luck with your project, ~
Brian

[Tom Henderson2]

Well.... often it depends on how bad the rust is.

I recently rehabbed a 40+-year-old saw. The top was stained and had some light rust, but nothing too bad.

The "Rust Free" product that is available bundled with a can of Boeshield worked VERY well for me. The trick is to keep it wet and wipe it off before it drys out.

I found a small electric detail sander at Harbor Freight for a few dollars. Also bought some scotchbrite-like pads for it. I sprayed on the Rust Free, and worked it with the sander for several minutes, rewetting with Rust Free as necessary to keep a wet surface. Then wiped it off with a terry towel. I found it best to do small sections at first, then a final appliation over the entire top.

It took a few cycles, but this eliminated all of the rust and 99.9% of the stains; the saw top looked almost like new.

As for rust prevention, bear in mind that Boeshield is essentially wax with solvents; there is no magic ingredient to prevent rust. The primary advantage to Boeshield over paste wax alone is the way the Boeshield will seep into nooks and crannies (like miter gage slots, etc) that are hard to get at with paste wax.

Paste wax probably leaves a thicker coating than just the Boeshield. But the corrosion-protection mechanism is the same.

-TH

[Lee Schierer]

Where I used to work, we quite often had to remove rust from cast iron surfaces. What we used was a cheap vibratory sander witha scotch brite pad clipped in where the sandpaper would normally go. THey would wet down the surface with WD-40 or light machine oil and then "sand: the entire surface with the scotch brite and sander. This would remove all the rust and leave the surface clean. Wipe down the WD-40 or oil and apply T-9 and paste wax.

If your saw is going to sit long periods between uses, then liberally apply T-9 to the surface and don't wipe it down, just let it dry. When you get ready to work again spray the surface again with T-9 and wipe it down. The second spray will soften the first coat which will be gummy and leave a nice clean surface.

[J. Z. Guest]

Bill, for some reason I can't figure out, folks here don't even consider Naval Jelly. It works like a charm, and with NO scrubbing or abrasives. Get a small tub of it at your local hardware store, follow the directions on the tub, and you're golden.

1 Wipe it on
2 Let it sit for a bit
3 rinse it off

[Brent Smith]

Hi Bill,

I just use mineral spirits, 400-600 wet/dry and elbow grease. Wipe off frequently and don't be cheap with the MS. To protect from further rust I use TopCote.

[Craig Summers]

Bill, for some reason I can't figure out, folks here don't even consider Naval Jelly. It works like a charm, and with NO scrubbing or abrasives. Get a small tub of it at your local hardware store, follow the directions on the tub, and you're golden.

1 Wipe it on
2 Let it sit for a bit
3 rinse it off

Naval Jelly is made from the same stuff they make Coca-Cola from: Phosphoric Acid.

The trouble with Naval jelly, is what goes on, must come off. you need to get it out of the cracks and crevices when done because it is acid. To do that correctly you have to wash it off (with water). Who wants to put water directly onto raw porous cast iron? I know, you could dry thoroughly with towels, and then use a blow dryer (heat) to remove any remaining moisture.

[Ben Cadotte]

I like 3m roloc disc's on an air die grinder for rust removal. I use them for rust removal on quite a few things. I buy them by the box so they are not as expensive. I have used the scotch brite pads with a half sheet sander. That works pretty good for light removals. Basically just a quicker method than doing it by hand. If your going to buy some stuff. Buy it in bulk as you know you will need more in the future. And it will work out way cheaper than buying 1-2 at the borgs.

[Matt Hutchinson]

I haven't tried this yet, but it's on my shopping list: malt vinegar. I have seen this mentioned on other forums, and if you search for something like 'vinegar rust removal' I think you will find some info on it. Since most people already have WD-40 on hand, it's not the most economical. However, it sounds effective and it may reduce the amount of elbow grease needed.

Hutch

[Mike SoRelle]

Naval Jelly is made from the same stuff they make Coca-Cola from: Phosphoric Acid.

The trouble with Naval jelly, is what goes on, must come off. you need to get it out of the cracks and crevices when done because it is acid. To do that correctly you have to wash it off (with water). Who wants to put water directly onto raw porous cast iron? I know, you could dry thoroughly with towels, and then use a blow dryer (heat) to remove any remaining moisture.

Or neutralize it with a base, but it's the same problem, eventually you want it rinsed back to neutral.

Naval Jelly is great, just not for equipment tops IMHO.

[Brian Smith3]

I'll answer as much as I can.

1) Yes you can cut Scotch Brite Pads. I use a set of normal scissors. Don't use your wife's sewing scissors, at least my wife did not like that.;-)
2) Honestly I don't know because I don't use a ROS. 3M has a LOT of products, so you may want to search their site. Personally I use a PC Speed Bloc sander with a $5 replacement pad that I dedicate to this job.
3) I use basic 3 in 1 oil (light machine oil) and a PC Speed Bloc sander starting with 400g wet dry. Then I move up from there.
4) Sanding the surface dry will gum up your sand paper at the finer grits.

My method is just to use a good quality wet/dry with my dedicated sanding pad and PC sander. When Im' happy with the finish I wipe on a coat of T9 let it dry overnight, then clean up the sander. Then the next day buff the top with a rag or a white pad until it is no longer tacky, then cover with three coats of wax and buff it out. For maintenance I use white Scotch brite pads and T9 Rust Off followed by the T9 and wax.

SCOTCHBRITE GRIT CHART
3M Scotch Brite Nylon Pads:
7445 - White pad, called Light Duty Cleansing - (1000) 1200-1500 grit
7448 - Light Grey, called Ultra Fine Hand - (600-800) 800 grit.
6448 - Green (?), called Light Duty Hand Pad - (600) 600 grit
7447 - Maroon pad, called General Purpose Hand - (320-400) 320 grit
6444 - Brown pad, called Extra Duty Hand - (280-320) 240 grit
7446 - Dark Grey pad, called Blending Pad (180-220) 150 grit
7440 - Tan pad, called Heavy Duty Hand Pad - (120-150) 60(?)
(The value inside the parentheses is directly from 3M and outside of the parentheses is what I have found with the pads.)

Hi,
I have a cast iron TS that has some mild rust. I have done some searching through the posts and have decided on a T9 and wax combo to prevent rust, but how do I remove it?
I like the idea of using my ROS and some Scotch Brite pads...but
1.) I haven't found round scotch brite pads...do you just cut them?
2.) How do they stay attached to the ROS?
3.) Do you use WD-40 with it and won't it get sucked up into my ROS?
3.) Is it better to use 220 grit dry sandpaper?
Any advice would be appreciated.
Thanks,
Bill

[glenn bradley]

I just brought back a 1970's Delta BS table. Gray pad on a 1/4 sheet sander and some mineral oil. 150 grit paper on the tough spots and then the scotch pad again. If you have some deep shadows, this works well but, wear a mask and gloves and don't let it set too long. Of course, Johnson's Paste Wax afterwards. I was greatly under impressed with the T-9, just my experience.

[Doug Shepard]

I've used WD40 and steel wool to clean up a number of things but it wasnt helping some spot stains I got on my TS top from snow blowing into the garage when I neglected to have it covered. Wiped it down right away but not too good I guess. Anyway, I bought me first bottle of Empire TopSaver based on recommendations, and I'm probably not going back to WD40 again unless I've got LOTS to do and then as just a prelim cleanup. The Empire worked great.