How Do I Protect Cast Iron from Rusting During Storage?

How Do I Protect Cast Iron from Rusting During Storage?

In the near future, I’ll be moving to a new house, but the timing is not going to allow me to set up my shop immediately. I will probably have to store most, if not all, of my equipment for several months in non-climate-controlled conditions. My question: How to prepare the cast-iron tables of saws and jointers, etc., to prevent against rust?  – Ernie Mascarello

Rob Johnstone: While there may be better ways to take care of the cast iron, when I recently moved my machines to a storage facility, I first slathered on a super thick layer of paste wax and just left it there. It “hardened” after a fashion … and I am sure it is hard as a rock right now in the super cold temperatures of my unheated storage unit. (And let me be clear, the location of that unit will remain top-secret!) A couple of days before I put the paste wax on the tools, I wiped the tops and exposed metal surfaces with paraffin oil. I will be able to tell you how well the iron survived in a few weeks.

Tim Inman: Cosmoline, which is a thick and waxy grease often employed by machine manufacturers before crating and shipping, would be the totally bulletproof material to prevent rust. It is also awfully messy. Actually, I think you would get along just fine by applying a nice heavy coat of beeswax to the cast-iron surfaces. Don’t polish it; just apply and forget it until it is time to set up in your new shop. If it is too thick and/or too hard, a cloth soaked in mineral spirits will always release it. You can make up your own beeswax paste by simply putting cakes of beeswax into a can of mineral spirits. It will dissolve wonderfully, and you have a great surfacer to use.

Chris Marshall: Warm and cold temperature swings aren’t really a big deal for stored machinery, provided the relative humidity remains low. “Hot and dry” or “cold and dry” will keep rust at bay. But throw moisture into the equation, and that’s where the problems begin. Aside from a wax-based metal coating that Rob and Tim are suggesting, you also could use a dry lubricating spray like GlideCote™ by Bostik. Just spray it on and let it dry to seal the metal. It’s probably the quickest and cleanest of these solutions, and in my experience of moving and storing machines, it has worked well.

Good luck on your home and shop move!

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  • John J Crouse

    Check Fine Woodworking magazine for building an oscilatting spindle sander. Rotate the head of a bench drill press and put a low rpm gear drive on the table with a connecting rod to the quill handle. Built one years ago, a big help in my shop. The oscillstion makes a BIG difference.

    As for iron tops a good paste wax

    • JERRY

      I HAVE FOLLOWED ALL OF THE ADVICE OF OTHERS ABOUT RUST ON MY CAST IRON TOPS AND STILL GOT RUST DURING THE WINTER IN MY UNHEATED GARAGE UNTIL I REMEMBERED WHAT I LEARNED,KNEW OR OBSERVED ABOUT C0NDENSATION. WATER WILL CONDENSE FROM AIR BECAUSES OF AIR TEMPERATURE FLUXUATIONS THAT HAPPEN QUICKER WITH AIR VS. A COLD CAST IRON SURFACE. ONCE WATER ACCUMULATES ON CAST IRON YOU WILL GET RUST. I CONCEDE IT COULD BE COVERED WITH SOME SUBSTANCE SO THICK WATER WILL NOT PENETRATE, BUT THEN WHEN I GET OUR USUAL SPRING THAW IN GREEN BAY I WANT TO BE ABLE TO USE TOOLS QUICKLY, AND NOT SPEND MY TIME WIPING GREASE OR OIL OFF SURFACES. THE TRICK IS TO KEEP AIR OFF CAST IRON SURFACE AND I DO THAT BY KEEPING SURFACES CLEAN,FREE OF DEBRIS,WAXED, AND THE REAL TRICK IS: COVERED WITH GLAD PRESS-N-SEAL WRAP. I FOLLOW THAT UP WITH MY SWEETHEART’S OLD OR NOT SO OLD TERRI CLOTH BATH TOWELS.(GIVES HER AN EXCUSE TO BUY MORE!!). WITH THE TOWELS JUST MAKE SURE IT LAYS FLAT AGAINST SURFACES.THE TOWELS WICK AWAY ANY CONDENSED MOISTURE. TOSS THEM IN THE DRYER ONCE A MONTH OR NOT, IT WILL GIVE YOU A OPPORTUNITY TO INSPECT FOR RUST, BUT IF YA DID IT RIGHT, THERE AIN’T GONNA BE ANY!!!

  • Al Horstmann

    What if you already have rust on the table surface? what is the best way to clean it?

    • jim b

      I purchased a tablesaw on which someone had set a can of soda or such but when can was removed it left a nasty rust stain. I used a da sander and mineral spirits. the sandpaper I used was 220 and finer then used paste wax to coat the top. hasn’t rusted again.

  • Lee Ohmart

    I had this problem up here in Maine when I was working out of an unheated garage with just a table saw. Every time it went from hot to cold or cold to hot, I would get condensation on the cast iron. I used what I had at hand and it worked beautifully. It was cheap, effective and cleaned up easily with paint thinner. Marvels Mystery Oil. Just pour some on a rag and coat all the surfaces you can get to. Because it’s thin enough, it gets down into cracks and crevices so there is no need to disassemble. When you’re ready to get back to work, just wipe off as much as you can and remove the rest with paint thinner.

  • rwhpi

    I recently cleaned surface rust from my 1978 vintage Craftsman cast iron table saw top. Spray the rusted areas with WD40 and use a 000 steel wool pad to remove the rust in each area. Do it in a circular motion and wipe dry with a rag. For heavier-rusted areas, do the same thing a few times over and it will gradually become renewed. Then coat the entire surface with paste wax; let it dry and wipe it with a rag to a smooth sheen. Make sure all of the rust remnants are removed with an additional spray of WD40 and a dry rag, before waxing. My hand tools are renewed in the same manner, with good results. I try to keep a coat of paste wax on all of my tops and hand tools every few months, especially during the humid seasons.