How to stop rust

[Gary Markham]

Just want to pass along something that works for me to prevent rust on your cast iron. Also lowers need to wax so often. I live on the Texas coast between Houston and the la state line. The shop is not climes controlled and everything sweats with the high humidity. I got a new hammer k3 table saw and a new griz 513 band saw at the end of 18. I waxed them as soon as I set them up but still had rust starting in just a few weeks of Jan night sweats. To try something different I ordered the rolled magnetic sheet material. 24” x 10ft from Amazon. Cut it to cover the cast iron and keep it on when ever the machines are not in use. Since doing this for over a year now both machines look like new. I have not had any rust at all on either one. The magnetic sheet works great for me. I still wax a few times a year
gary

[David Buchhauser]

That's a great tip Gary!
Thanks,
David

[Alex Zeller]

In the past I've looked around for some that's wide enough for a table saw without much luck. It seams to be readily available in 24" wide rolls of every length.

[lowell holmes]

I use Johnson's floor wax.

[ChrisA Edwards]

I use Johnson's floor wax.

Likewise, but I have a few tools that spend more time idle than in use, and over a period of time, say several months, they will start to show some light rust.

I'll still paste wax them, but for the relative inexpensive cost of this, I'm going to give it a go.


Gary, thank you for this tip, I'm ordering some.

[Matt Day]

In the past I've looked around for some that's wide enough for a table saw without much luck. It seams to be readily available in 24" wide rolls of every length.

Surely you could mend two pieces together to make it wide enough. Or glue them to a piece of plywood.

[Erik Loza]

Great tip, never would have thought of that. Thanks for sharing.

Erik

[Alex Zeller]

Surely you could mend two pieces together to make it wide enough. Or glue them to a piece of plywood.

I'm assuming that the whole point is the condensation will collect on top of the sheet. Any joint could let the water pass to the iron. Still you could line up the joint with the miter slot or put a lot of wax under it. However simply having a sheet large enough would be the simplest way.

[Ray Newman]

Another rust prevention product are the HTC tool covers. Back 1987 I bought one for my Uni-saw which was in an unheated garage. Still use it in my new shop here in Washington. After the first year of no rust use, I bought others to cover other machines.

Amazon lists them in various sizes. Largest size is 72 X 122” for US $45.00

https://www.amazon.com/HTC-TS-9072-Breathable-Protects-Valuable/dp/B000022628/ref=sr_1_2?keywords=machine+tool+covers&qid=1585252608&sr=8-2

[Richard Coers]

Why does it need to be magnetic? Seems like a piece of 1/8" hardboard would do the same thing, and cheaper.

[Robert Hazelwood]

I've had good luck in an unconditioned garage with a mixture of Boeshield and paraffin. The Boeshield is kind sticky on its own, so right after I apply it I rub a stick of paraffin all over the surface then buff. The Boeshield solvents help the wax coat evenly and the paraffin makes it slick. Seems better than either on its own and lasts a while.

[Kevin Beitz]

Slipit is made for table saws to stop rust...

[Gary Markham]

One of the reasons i think it works better than some other covers like hardboard is the magnetic enables full tight contact with no place for air that would have moisture. My mechanic tools are soaking wet some days even though they are kept in a good drawer roller cabinet. With our temps and dew points there are some days where the steel temps of items in the shop never get above the dew point temp so that means they sweat like a frozen beer mug in most areas. Keeping the tops sealed with no contact to air is the trick. I sill wax with Johnson’s just not as often. I have not done this yet on my planer and jointer and they need constant scraping and wax from the condensation. I gave my extra material to my son for his new saw and need to order more. I I needed something wider than 24 I would lay then edge to edge and cove4 the joint with gorilla duct tape
gary

[nicholas mitchell]

Slipit is made for table saws to stop rust...

Rebel ;) ...

[Eugene Dixon]

And, I just put an old towel over the tables. Occasionally I'll add the floor wax.

[Bradley Gray]

I use a fan to remove condensation from a big planer and jointer I use in an unheated space - but in my climate, condensation on the machines only happens a few times /year.

[Richard Coers]

It's my opinion that the moisture settles on the cast iron. In our farm shop, if you left a crescent wrench on the drill press table, you could see a clear outline of the wrench while the rest of the table was covered with flash rust.

[Charles Lent]

Learn what the term "Dew point" is and take steps to avoid the temperature/ humidity ratio where dew point becomes a problem. Dew point is the temperature at which the relative humidity in the air at that temperature becomes 100%. If the air temperature drops below this point moisture in the air will begin to fall out of the air or form droplets on colder surfaces like your cast iron. Keep your cast iron above this temperature or the humidity below it and you will have no rusting problems.

Charley

[Doug Dawson]

Just want to pass along something that works for me to prevent rust on your cast iron. Also lowers need to wax so often. I live on the Texas coast between Houston and the la state line. The shop is not climes controlled and everything sweats with the high humidity. I got a new hammer k3 table saw and a new griz 513 band saw at the end of 18. I waxed them as soon as I set them up but still had rust starting in just a few weeks of Jan night sweats. To try something different I ordered the rolled magnetic sheet material. 24” x 10ft from Amazon. Cut it to cover the cast iron and keep it on when ever the machines are not in use. Since doing this for over a year now both machines look like new. I have not had any rust at all on either one. The magnetic sheet works great for me. I still wax a few times a year

Sounds like you need a dehumidifier in your shop.

[Larry Edgerton]

Keep in mind that no matter what you put on the top you are not protecting the internal parts that are bare. Conditioning the air is the only way.

[William Hodge]

Keep in mind that no matter what you put on the top you are not protecting the internal parts that are bare. Conditioning the air is the only way.


I see these threads here from time to time. The focus seems to be on protecting cast iron tables. I always wonder what's happening to the un-waxed bare metal, like insides of machines, electrical connections everywhere, and all kinds of hand tools. I have bought old machines with the insides of the electrical control boxes all corroded from moisture.

Perhaps a bigger concern is the lumber. I store lumber in the shop, so that it will be dry when I need it. If the wood gets cold and damp, it will be wet. Sheet goods don't bounce back from being wet.

Finally, if your shop is so wet that moisture is forming on everything, you have good potential for a mold problem.

I even deal with moisture and wood problems in my wood sheds. The sheds face south, and are open on four sides. I dry firewood to 11% moisture content. However, when it gets warm and wet after being cold, water will condense on the wood. The sheds are lined up to catch the west wind, so when fair weather returns the west wind blows between the spaced stacks in the shed, and the wood dries out again.

[Alex Zeller]

A lot of the problem is the change in temperatures. Metal once cooled down (say at night when the temp drops) will stay cold as the air warms up. Moisture will then condense on the colder metal. It doesn't just fall down but it will pool on the top of flat surfaces. The underside of a tablesaw table will also rust but it's not going to impact anything. Of course gears, rods/ bearings, and machined parts do need protecting but since they don't come in contact with the wood for your project different sources of protection can be used. Any moisture that does collect will either run off the underside or evaporate. The idea of using a magnetic sheet is that the magnetic force will create a seal so water that collects on top of the sheet can't find a way between the sheet and the cast iron.

[Frank Washer]

I have a climate controlled shop, but here in NY I still get a little surface rust if I don't keep the heat or ac on. I just repolished some cast iron tops on a PM 60 jointer & am going to try clear coating them & see if that works, I have been covering with card board as I don't use the equipment often & that seems to really keep any moisture off.

[Ray Newman]

Larry Edgerton and Alex Zeller mentioned "conditioning" the air. Besides the HTC covers, I run a Modine Hot Dawg heater with a low temperature thermostat. Also keep the doors on the shop cabinets open to allow better air circulation and prevent rust on the tools.

[Larry Edgerton]

Larry Edgerton and Alex Zeller mentioned "conditioning" the air. Besides the HTC covers, I run a Modine Hot Dawg heater with a low temperature thermostat. Also keep the doors on the shop cabinets open to allow better air circulation and prevent rust on the tools.


I keep the heater at night at 40, thats all it takes. In the summer the A/C barely runs, but it is just enough to control the moisture, and makes it a lot nicer to work as a bonus.

[Ray Newman]

Larry: I keep the thermostat at 46 degrees. Next season, just might turn it down another notch or two.

As an aside, I recall reading about a woodworker who had his tools in large metal wall and free standing cabinets and kept the rust at bay with Golden Rod heaters. I have Golden Rods in both of firearms safes and they work very well and last a long time. The last one replaced worked for about 15 years. Am thinking about a small one for a wood tool cabinet.

For Those-Not-In-The-Know 'bout Golden Rods: http://www.best-dehumidifier-choice.com/goldenrod-dehumidifier.html

[ChrisA Edwards]

Got my 24" x 10' roll of magnetic sheet today, thank you Amazon. I'll be cutting it to match various machines tomorrow.

[Jim Andrew]

Since I layed down sleepers, 1" dow board, and t&g flooring, the temperature in my shop does not fall as low as it used to, and have not noticed any rust at all on any machines. Did wax the table on my shaper a week or so ago, helped the power feeder feed some frame material. BTW, I bought some slipit, and it did not seem to want to dry. What is the proper procedure on using Slipit?

[Carroll Courtney]

Gary you added another method to combat rust,thank you. I always keep sheet over my equipment,its not the answer but it helps.

[Jim Becker]

Since I layed down sleepers, 1" dow board, and t&g flooring, the temperature in my shop does not fall as low as it used to, and have not noticed any rust at all on any machines.
Keeping the shop air above the dew point really can help with this. A lot of rust problems on machinery is due to condensation because of temperature.

[Malcolm McLeod]

Keeping the shop air above the dew point really can help with this. A lot of rust problems on machinery is due to condensation because of temperature.

^^This would certainly keep it from raining in the shop! :eek:

I'm with Alex. I have always believed the machinery must be kept above the dew point of the air, or the dew point of the air below the temperature of the machinery. So, either the tool 'warm' (relatively), or the air 'dry'. Either one will prevent the moisture in the air from condensing on a rust-prone surface.

[Jim Koepke]

Sounds like you need a dehumidifier in your shop.

One problem with a dehumidifier is in an unheated shop it can freeze up in cold weather.

jtk

[Doug Dawson]

One problem with a dehumidifier is in an unheated shop it can freeze up in cold weather.


It's about as unlikely to freeze in Port Arthur, Texas as it is to rain frogs. (Maybe I spoke too soon? :^) But more generally, yeah.

[ChrisA Edwards]

Let the experiment begin.

One roll of 24" x 10' of magnetic vinyl, $42 delivered to me with tax (https://www.amazon.com/Magnum-Magnetic-30mil-Flexible-Material/dp/B00FULC6OC/ref=sr_1_5?crid=KCCM2TTW1L0O&dchild=1&keywords=magnetic+vinyl&qid=1585589311&s=office-products&sprefix=magnetic+v%2Coffice-products%2C151&sr=1-5)

I have 4 power tool tops and beds covered, got a couple more to do.

Stuff was easy to cut and goes on in a couple of seconds. I also like the fact that it gives a bit of upper surface protection as well, I tend to put things down on top of some of these tables when that tool is not in use.

https://i1094.photobucket.com/albums/i452/cedwards874/Woodworking/Magnetic%20Vynil/HammerA3-31Cover_zpss4hyd4ob.jpg


https://i1094.photobucket.com/albums/i452/cedwards874/Woodworking/Magnetic%20Vynil/Laguna1412Cover_zpsjcyb3xon.jpg

https://i1094.photobucket.com/albums/i452/cedwards874/Woodworking/Magnetic%20Vynil/LatheCover_zpsc80vgeic.jpg


https://i1094.photobucket.com/albums/i452/cedwards874/Woodworking/Magnetic%20Vynil/JetBeltSanderCover_zpsyw0ovd3t.jpg

[George Yetka]

I went 9 months with no protection when I first got my table saw/bandsaw. then I had a crazy warm day in January followed by a wet night and somehow the garage filled with moisture. overnight my hand tools and cast iron tops rusted.

I cleaned them all up and glidecoated everything and oiled my hand tools. I ordered a dehumidifier that night and though it does run quite a bit Nothing has rusted since. I oil/coat every few months or as needed. I also added these to each drawer.
https://www.amazon.com/Hydrosorbent-OSG-40-Dehumidifier-Desiccant-Chloride/dp/B0037Z8K3E/ref=sr_1_4?dchild=1&keywords=dessicant+reusable&qid=1585593700&sr=8-4

[Alex Zeller]

When the dead of winter can reach -40 and you are a part time hobbyist keeping your shop heated isn't always practical. It's the extreme temperature changes that cause problems around here. I wish I could get away with a dehumidifier. I'm trying to find someone local who has a mini split heat pump. I know they don't work down that low but if something like this could be a good addition for those nights when the heat pump isn't going to cut it.

[Charles Lent]

When air is very cold, like -40, there is almost no moisture in the air. When warm air is cooled, any significant moisture that is in the air must be given up as the air is cooled. This is the "Dew Point" or temperature at which the moisture begins to condense out of the air. When it does, it will form on any surface that is colder than this dew point temperature. The warmer the air, the more moisture that it can hold, but as this warm air cools, much of this moisture must condense out of the air because the cooled air can no longer hold it. The temperature/humidity ratio at which the air humidity begins to fall out of the air is the dew point.

Very cold machinery will develop condensation on it and rust will form when brought into a warm shop because of this, but if the shop stays cold (below dew point) condensation does not happen. Keeping the warm air relatively dry with a dehumidifier or air conditioner will keep the dew point low, so moisture won't condense out of the air if the temperature drops some. If it drops a lot, and suddenly there is a good chance that the dew point will be reached and the moisture in the air will begin to condense. In the Summer, when we get a cold front, it will rain, because the cooled air will cause the moisture in the air above it's dew point to condense. The same thing happens in your shop as warm air is cooled, but it's slower and not near as violent because the air temperature is dropping more slowly, but it will indeed rain on your tools, just in very small droplets. Covering the tops, just like throwing tarps over outdoor items will protect the tops from the rain, but not the internals.

keeping the humidity of your shop air low will keep your tools from rusting, even if the shop temperature varies, as long as it stays above the dew point. Keeping the humidity of the air in your shop relatively low will also help you preserve your wood and projects that you make won't shrink and split when you take your finished projects into your warm, relatively dry homes.

My shop is less than 20' above and about 100' from a 300 acre lake. When the temperature outside falls rapidly to below freezing, my cars and trucks develop a thick frost on them. My shop is well insulated, so the temperature doesn't change that rapidly, so I don't have severe rust problems on my shop machinery and I never cover them. I do have heat and air conditioning in the shop, but only run it when I am there or if the temperature outside will go significantly below freezing for an extended period of time, and mostly to protect my water lines, latex paint, batteries, etc. from freezing. I do wax my cast iron, but almost never see any evidence of rust on anything inside my shop. The wax is applied more to make project wood slide over the surfaces easily than to protect the metal from rusting.

Charley