Table Saw rust
I seem to be running into a recurring problem with surface rust on my table saw. Most of the time, there isn’t any, but a while back I had to get rid of some surface rust. Then just three days ago, I noticed that I had a very light surface rust over about a third of the top. I got rid of it using a mixture of lemon juice and salt and 00 steel wool as I had done previously. I then sprayed the top with Topcote. Tonight I noticed that the rust was starting to come back. We live in a very dry climate, although it did rain last night, and there definitely has not been any moisture spilled on the top.
Questions: Is there a better product for getting rid of the rust? Is there a better product for protecting the top from more rust? If car wax would work well, which ones work best?
Thanks for the tips. This is time consuming and annoying as well as destructive.
A couple companies, Boeshield (sp?) is one, have kits that remove rust, and then treat the top to prevent rust and to lubricate.
Another method in Naval Jelly to remove it, and a coat of furniture wax or paste car wax to coat it and protect it.
I like the wax, especially when using a sled on the table saw. A coat of wax on both surfaces make things slide quite easily.
Try cutting a Scotch Brite pad to fit your RO sander; spritz a little paint thinner or Boeshield on t he table and "sand" away. Works really slick.
Don't use regular car wax on any of your tools -- too much moisture in wax, and can actually promote rust. Remember that car wax is formulated for painted surfaces.
Regular old furniture wax is the way to go.
Your use of salt might be the culprit here. If there's any salt left on the metal surface, seems like it would draw water out of the air. I would clean the saw with mineral spirits or WD-40, using a sythetic pad or wet/dry sandpaper. Wipe it down really good with mineral spirits again, using a towel, to get particles off the saw top. Let it dry awhile, then wax with a good furniture paste was (Johnson's, Butcher's wax, etc.) and buff. A couple coats. That should do it.
Of course, there's always Boeshield and the other coating products on the market. One that's been getting good press lately is "TopSaver." Cleans, protects and lubricates all-in-one according to the manufacturer.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Doesn't automotive wax contain silicon? If so, another reason to avoid it (and the WD-40) in favor of a furniture paste wax. That can cause some finishing problems with your wood later on.
Is your shop air conditioned? If so, it's possible that the metal is cold enough to cause condensation in the presence of warmer, humid air.
I think FG's insights about the salt may be accurate with regard to the re-occurance of the rust. All the ideas are good...I use a bit of shoe polish because I have it laying around...
WD-40 is safe enough to use as long as you clean it off (mineral spirits) and wax afterwards. I don't like to use it, but have when the degree of rust was more extreme.
Regarding a different comment above, Naval Jelly is wicked stuff! I totally avoid it on nicely surfaced metal such as a table saw.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I take it you've had a bad experience with Naval Jelly. I'm thinking of using it on the inside of a steel gas tank that's rusted bad enough to contaminate the fuel but not to the point of leaking (yet).
What do you think?
"WISH IN ONE HAND, #### IN THE OTHER AND SEE WHICH FILLS UP FIRST"
A good lubricant for sanding rust off of cast iron, or other metals, is white vinegar. If you remember from chemistry class, vinegar is a weak acid, and does wonders when it comes to cleaning. As for acidic residue, I really don't think you need to worry about it. We use vinegar to clean the internal mechanics of some of our older mechanical gyroscopes, and we also use it to clean the glass in our newer zero lock gyros that use laser light to determine position. I would think that if it is safe enough to use in a very, very sensitive navigation instrument, then it is safe enough for tools.
As a side note, vinegar is also good for cleaning concrete. Just pour it over a stain and let it sit for a while. When you clean it up, you will see a big difference in even the basic color of the concrete. it looks almost new :)
Lazarus"Wisdom is the toughest of teachers! She gives the test first and the lesson after."
Edited 7/9/2004 12:17 pm ET by Lazarus
Vinegar used to clean router bits years ago turned them dull looking old and bad.
It's still an acid similar to lemmon juice, which are corrosive.
It's possible that metals of fine instruments are impervious to vinegar due to their high quality, but for tool steel, it may not necessarily be adequate.
Rather than acidic, alkaline cleaners seem to be more correct for woodworking tools sap, such as oven cleaner.
One cause for corrosion at the table saw might also be galvanic action. It'd make sense to check to see if any metals like aluminum are screwed or bolted to the cast iron.
Where it's corroded, it'd help to paint it with some clear varnish, and wipe it so the varnish stays in the crevices and keeps moisture out from them.
Hi Mack, sorry I'm late in replying -- been down-and-out (sick) for a couple of days.
My main complaint about Naval Jelly is what it does to the metal appearance-wise. The inside of a gas tank isn't expected to be pretty, I guess, so from that perspective it shouldn't be a problem.
However, please ask some people who know more than I do about what precautions you might need to take for other, non-aesthetic, reasons!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Humm,lots of ideas here. I've always stuck with the ROS and then WD40 with steelwool and wipe down with a clean cloth. Windex for quick touchups.
I have been using machine covers on the tablesaw and shaper for years. Protecting them from settling moisture helps a lot.
Hope you're feeling better! Summer is no time to be sick---what's up wit dat!
You are referring to the Naval Jelly turning the metal almost black, I imagine. That won't bother the inside of the gas tank. I've heard about it but have never used the stuff before.
Get well and enjoy our summer while it lasts!!
Mack"WISH IN ONE HAND, #### IN THE OTHER AND SEE WHICH FILLS UP FIRST"
Hi Mack, the motorcycle stuff sounds like just the ticket, doesn't it?!
Thanks for the healthy wishes. I was down and out for 2 days, but pretty much up to full speed now, although walking uphill still a chore. I've been taking the big collie out for exercise by turning him loose in a pasture with 2 Golden Retrievers. They maul each other and run around like crazy, while I walk around quietly and soak up the sunshine.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
That's the ticket! Let those "puppies" burn their energy; you conserve yours! Glad to hear you're feeling better. Nothing more depressing than being sick when the weather is beautiful!
That "motorcycle" stuff does sound very interesting. I'll have to look into it before I have a go at this gas tank.
Regards,"WISH IN ONE HAND, #### IN THE OTHER AND SEE WHICH FILLS UP FIRST"
Your local motorcycle shop ought to have a preparation for cleaning rust from your tank. Motorcycle tanks rust a lot, because many are left unused for long periods of time. I used a two part prep on the tanks of my antique bike. The first part was mixed with water and filled the tank completely. After a couple days, the tank is emptied, and the solution replaced with another, to neutralize the first. Also you can get a third preparation that coats and seals the inside of the tank, (altho this has gotten mixed reviews from people more knowledgeable than I). I had good results from the cleaner/neutralizer combo. Can't remember the brand name, but any good cycle shop should be able to help you.
Thanks for the heads up, I'll stop by and talk to someone about it.
Mack"WISH IN ONE HAND, #### IN THE OTHER AND SEE WHICH FILLS UP FIRST"
I'd avoid chloride (salt, muriatic acid) because it's so effective at causing rust. If you use it to dissolve remove rust, you will need to make sure you rinse away every trace when you're done. Then you want to protect the surface with something that soaks into the tiny pores where the rust gets started. Boeshield T-9 works well:
I think the rust remover in this set is mostly phosphoric acid. I would have thought it a good idea to get rid of traces of this too, but I've just wiped it off and applied T-9, without any subsequent rust. The blade and bit cleaner in the set works well too, but so does "simple green" cleaner, which is much cheaper.
I only use the T-9 after really cleaning the top, and periodically wax to make sure it remains slick. Crumpled waxed paper is quick and works quite well.
The cast iron in the table top is slightly porous, and, I'm guessing, soaked up a bit of the lemon juice (ascorbic acid). The re-emergence of rust is probably this soaked-in lemon juice reacting. The good news is that it's probably finished doing any damage now.
I'd coat the top in a wax - as I'm not local, I'm sure that you'll get plenty of suggestions.
edit: just saw the reference to salt that I missed the first time - this causes a phenomenon known as crevice corrosion that continues to propagate - google on the term for detail. You need to remove the chloride ions before you seal them in with a wax - a good wash down in alcohol to draw them out of the pores first might do it without introducing more water to your saw table.
Here's a link from google: http://www.corrosion-doctors.org/Localized/Crevice.htm
Edited 7/8/2004 4:01 am ET by eddie (aust)
As someone pointed out below, ascorbic acid (vitamin C) is a minor component of any citrus juice, citric acid is the major contributor to acidity.
Edited 7/8/2004 6:29 am ET by eddie (aust)
I use a 500 grit abralon pad with some WD40 and then wipe it off. Works fine here in Australia where it can be humoid in the summer months.
WD 40 is an excellent protector of such surfaces and particularly useful for woodworkers because it doesn't attract sawdust as well as most similar lubricants. It leaves a sort of parrafin coating that is slick but won't gather dust and become gooey. I used to use it all the time on the big panel saws and also large table saws in plants where I was maintenance foreman. Salt is a bad idea because besides attracting moisture it is also likely to create electrolysis and other chemical reactions when applied to metals. As a metalsmith I use it for creating etched patinas but you DON'T want that on your table saw top. Lemon juice is an acid (citric) and will corrode metals too. Use abrasives to remove the rust and then treat regularly with WD 40 and you will have few problems in the future.
Where are you that it has been humid in summer for the last 3 years. (we have just had the lowest rainfall on record for two of the last 6 months although Jun was spot on - perhaps spring will be OK again this year)
I am in Saint Louis. When I lived in Idaho I would sometimes hose down my jeans on hot days to achieve a sort of swamp cooler effect ... here there would be no point because you are sopping wet from sweating anyway. Idaho is a high desert climate (in the treasure valley anyway). Saint Louis is river bottom swamp climate. I often have to work without my glasses because it is just impossible to keep them dry enough to see through.
Try cutting a thick piece of insulation board (blue or pink) slightly oversized to the cast iron top you are trying to protect. An insulated top keeps any condensation from forming. Also, use Johnsons paste wax to protect. I've had no problems here in the midwest since a friend suggested this.
If I wanted to rust a piece of iron in a hurry I would apply either an acid or some salt or both. Your salt and lemon juice technique is guaranteed to lead to rusting problems.
Cast iron is porous so the salt and lemon juice are down in the metal and will probably always make the table more rust prone. In addition to its chemical reaction with iron, salt is hygroscopic, it will absorb and concentrate moisture even from relatively dry air which is why the problem is occurring right after rain storms.
Using an oil or wax is the best approach to limit further rusting. You might try washing the table down with water a few times to dissolve and remove as much of the salt and acid as possible first.
My Grizzly jointer manual recommends talcum powder to "seal the pores" and prevent rust. 'never tried it. Although I do have big rust problems in the winter here in the Pacific NW.
I've seen talcum powder recommended by a number of woodworkers, including professionals who've been around for quite awhile. Seems to be a tried and true practice, though I've not tried it myself. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Forgot to mention earlier Dave, that the best way to keep the rust off the surfaces is to keep the dust and condensation off them - I have a cover (a few old sheets and blankets) that I put over my saw, and clean the thing down well when I'm finished with it.
Re Grizzly's suggestion to use talcum powder (Calcium carbonate/Magnesium carbonate) to fill the pores, I'm suspicious of it - just my experience, but they tend to hold moisture, but, then again, they must have a solid reason for suggesting it.
A-yup, I had this problem oncet on my old tablesaw. Darndest thing. Couldn't figure it out. Cleaned with sandpaper and re waxed with Butcher's Wax. A few days later, there was another ugly load of rust on top. This time I happened to look up and noticed that there was some real ugly green on some bits of copper pipe I had stored overhead. That got me to thinking...
We had a couple of foster kids living with us at the time, and the brother was scared to death of dogs. Old Beau slept out in the hall, keeping watch over his charges by night. The poor kid woke up in the middle of the night, wanted to use the john, opened the door to Beau... He used the closet instead (right above my saw).
Thankfully he decided real quick that Beau was going to be a great pal, and he needn't be afraid of Beau (or, by the time he left us, dogs in general).
Interestingly, I use kosher salt to clean our iron pans, griddles and the like, and it works great, but it would never have occured to me to use salt on a machined surface. I have used Muriatic acid to clean off rust, with mixed results.
I live in Southeast Texas near Galveston Bay, high humidity, lot of rain and everything rusts. I have a garage saw I bought from a neighbors garage last year. It was covered up with boxes, I had saw the saw a few years ago and it looked good then. I would not have bought it had I knew what was under those boxes. Covered with rust completely almost, what wasn't covered with rust had dried house paint. I planed the top down with a single edge razor blade, removing the paint and most of the rust, Using an electric pad sander and WD40 I was able to restore the top completely.
I have used Baby Powder for many years on my equipment iron surfaces to keep down rust. I have a Unisaw in my workshop that is not as exposed to the changing temperatures and humidity as my garage saw, they both get a light coating of BP when I finish for the day. It works for me.
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