Preventing rust on my Index Modle 40 Mill

I Have a Index Model 40 Mill In my shop And I want to protect it from rust this winter, Last winter I used a electric heater near the mill and it seamed to work ok but my electric bill was way too high to try this again this year. Would covering the mill with a electric blanket and spreading moth balls on the table work to protect my mill ?

AS the temperature varies in the unheated shop, the dew point changes

The machine tends to stay colder, thus moisture condenses on it.

You can either keep the machine warm or try to keep air away from it

I would consider adding some insulation and air sealing to the shop, it is usually cheaper long term than heat.

If you keep the heat at 40 or so it greatly helps with condensation and depending on the space, not that expensive

Dissolve some beeswax in turpentine and paint it on all the large exposed surfaces. I've been doing this for about fifty years and works for my unheated shop.

I started running a dehumidifier in my garage a year ago and it has made a huge difference. I no longer get rust on my equipment and tools. It runs a lot however as I open the big door a couple of times per day and even with the door closed there are a lot of air leaks. In a sealed shop a dehumidifier would work even better.

I have been fighting this battle for quite a few years. Sealing up my shop is not feasible for many reasons. In the climate I live in there are days when the temperature and humidity will go way up all of a sudden. In a shop with no conditioned air, everything with any real mass to it will get wet. For a semi permanent fix I use bees wax and turpentine. Kind of a poor mans cosmoline. For the other things I use (and I hate to say it) WD40. I buy it in the gallon cans and just put it in a spray bottle like an old Windex sprayer. If you hose down your more massive chunks of iron it actually does a pretty good job. In my opinion it's about the only thing that stuff is good for. It will turn a milky white on humid, balmy days but there is no rust underneath when you wipe it off. My precision tools are kept in a series of Vidmar cabinets along one wall and have heat mats in the bottom drawers ( I put items I rarely use in the bottom drawers). These are the cheap low wattage mats made for green house growers to get plants started. They are under ten watts and about ten dollars a piece. Like these:

Amazon.com : MET certified Seedling Heat Mat, Seedfactor Waterproof Durable Germination Station Heat Mat, Warm Hydroponic Heating Pad for Indoor Home Gardening Seed Starter(10" x 20") : Patio, Lawn & Garden

I use paste wax.
I had a tin of some marine packaged stuff which was quite hard and I used it for sliding surfaces on the planers etc but also for general rust proofing.

Amazon.com: 3M Marine Ultra Performance Paste Wax (09030) – For Boats and RVs – 9.5 Ounces : Sports & Outdoors

I ran out of that so I'm just using some Johnsons paste wax now.

The marine stuff by 3m was great though- might be worth picking up a tin and trying it.

I would hit it all over with LPS2. LPS-3 is also good (better actually long-term) but will build to a waxy film unless you keep wiping it around.

By far the best at keeping my machine tools rust free .

Ps my shop is unheated in an area that receives approximately 90" of rain a year

I have used ISO 46 or 68 hydraulic oil for rust protection on machinery in the past. Does work and will last several months before needing to reapply. Suggest this of indoor use only, not exposed the outside elements. Not a fan of WD-40. They do have a formula for rust control and preserving metal surfaces from rust in storage. The company I work for uses it, but they are in a lower humidly climate. (Spell check sucks) Don't know how it would work in higher humid environments.

Edit: Another thing that helps is to take a heavy cotton canvas cloth and cover your machine with this. Of course, oil down the machine before covering. I don't recommend putting a light bulb under this for fire hazard reasons but could be done.

I'd probably go with oil or wax, but if you want to keep it warm, how about building a tent over it with plastic sheet and using a small oil-filled heater?

Thank You to all ,super great ideas . I will let you folks know how My Mill made it thru a western New York State winter this spring.

Lots of good input here. One important point that has been made is the impact of temperature on humidity level. When it get's sufficiently cold the humidity can become a non-issue because cold air cannot hold as much moisture as warm. In Maine I get to a point, below about 35 deg where I don't have to worry at all about rust, whether my shop is heated or not. It's much cheaper and easier to have a system in place that has closed-loop control over this though, and just isn't running in a 100% duty cycle. My biggest struggle with humidity is actually in the summer and fall, not the winter, but day to day my dehumidifier just does it's thing and I don't have to worry about it. We can go weeks in the fall with beautiful days, but cold enough nights that rust would be an issue in the morning. A tiny bit of heat at night and I might not need dehumidification at all, or vice versa, but again I don't have to worry, and am not running something all the time for those perfectly wrong conditions.

An uncontrolled electric blanket would be similar to an electric heater in that regard, but likely much lower wattage. Easy enough to calculate the cost over a month and decide if that's viable.

The tenting is a good suggestion. I would personally go as far and say get yourself some real heavy vapour barrier (Poly) sheeting. Completely enclose the machine, tape down all seams with Tuk tape, tape and seal the concrete floor, seal everything off air tight save for one outlet. Tape that around your shop vac and hook it to draw a vacuum from the machine, tape the end around the hose with a funnel neck that you can clamp down and tape sealed while the vacuum is still on. After you've vacuumed out all the air, and tapped the outlet shut, shut off and remove the vacuum hose.

(even if it's not completely air tight, this should help to remove a lot of the moisture and restrict air inflation as well as moisture)

You can seal any sensitive areas of steel with a wax or something if desired. Additionally if you need even more protection I would then add insulation to the outside. As primitive as taking lose bats and laying them along all the surfaces and then perhaps draping a painters drop cloth on top to keep the insulation in place. If you wanted to heat that you could get a heater with a remote tube to "pump" warm air into/ under the drop cloth/ insulation; but if you're going that extreme you could build a little structure around it also that you could reuse and heat when required.

If hearing anything, get yourself a real thermostat (even a line voltage T-stat) and connect that to your heater (an electrician can help you); do not rely on the heaters T-stat. Additionally I would purchase one of those remote digital temperature sensors (like a small weather station). Place the remote sensor on the machine table inside the vacuum (use fresh batteries every year, you don't want them to die a month in), then put the receiver in your house or office so you can monitor the true temperature. Set the T-stat at the minimum (a basic thermostat is sufficient, you don't need a fancy programmable one), set it down at the minimum just above freezing like 10°.

That's my two cents.

A guy named Dave that I used to work with had a mill that would rust. He ended up building a box around it from 4x8 Styrofoam. Inside he put a halogen light, and this kept it warm.
Eventually, he insulated the whole inside of his barn with foam.

Goldenrod heater is the brand I know of. A string of christmas lights is also a good heat source. the LED type are lower wattage and not a fire hazard.
Bill D

Thanks I like the idea of the heat mats....

Thank you to all for the great info this helps a lot....

Cheap oil sump heater, stick it inside the column, done. ebay search line "Magnetic engine heater"


I've also taken hot glue guns apart and clamped the heaters to aluminum plates, get them at garage sales cheap!

For drawers of precision measuring tools buy Indian Camphor ("Indian camphor"), drill a few holes in the plastic case and toss into the back of the drawer. I do it and get no rust BUT my building is insulated so I might not anyway. It's said to stop steel from rusting though. I have a tool box in my unheated hangar, I need to get some for that. I also have 5 machine tools in that hangar that have plastic fabric covers over them and a small 40 watt light under each of them, that works too but is a bother to get at in a hurry.

If possible the best way is insulation.

I have been using this stuff for a bit and it seems to do a pretty good job on my 2 wheel and 4 wheel toys but I haven't tried on a machine for long term storage. It does work pretty well and I am in a very high humidity environment.

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