Rusted Tools

My personal shop is unheated and I'm in NY where winters can go below zero Fahrenheit and summer sometimes over 100. I do have a space heater I put next to the workspace if I'm forced to work in the extreme cold to take off the edge. Where my problem comes in is on the spring and fall days where the temps are sub-freezing at night and then above during the day, my tools get condensation on them in the box and on the shelf which then forms rust. I'm not sure if there's anything I can do to minimize this short of heating the building but figured I check with you all here. Any ideas?

Maybe your problem is building ventilation. Do you have turbines or vents and such for the roof? Here in Minny, we have wide fluctuations in temps as well and the only time I have a moisture problem in my unheated shops is the spring. The ground freezes normally to about six feet deep. In the spring, warm air hits the frozen floor and causes the floor to sweat. Here, it only last for a short period, a month or so.
You may try plugging in a fan during that period.

Warm air touching cold surfaces causes condensation. You have to remove one of those items to prevent it. Don't forget if you are burning open flames inside, you are also creating moisture. I might try setting up an electric heater or vented fuel burning heater of your choice. That should help out a good bit with the moisture/excess moisture.

I have the same issue here on my work truck. The warm and humid days during the warm months wreak havoc on my metal tooling. I have to shoot them with WD40 and wipe them down which seems to help somewhat.

I feel your pain. Stuff in my sheds does the same when the temp fluctuates

It's always wet here except for July, August and part of September. I leave most of my stuff oily and dirty, especially if I don't use it much. I still get rust on things like my 3/4" ratchet. My bars and heavy stuff are just normally rusty.

Redneckracing described what's happening, the warmer air condenses on the cooler interior. Warm spring days will usually have a higher dew point than the frozen soil and concrete.

Best solution is a vented heater. Unvented heaters will build up moisture all winter, a vented heater can warm up the shop in the spring, then use a dehumidifier and a ceiling fan inside. Any heat through the winter will dry out the concrete and structure. Exposed wood will act like a moisture buffer, so a mild dessicant if it's been dried out over winter.

Also, helps to tighten up the shop, no air leakage, no moist air coming in. A dehumidifier works good if it gets warm enough. The dehumidifier will add the total of electricity it burns, and the latent heat of water it condenses, 1,000BTU/pound. If you get a rare warm dry windy day, open the doors and windows to warm up the concrete slab.

If you have an exposed south facing wall of the shop, a solar dehumidifier is easy to build. Basically a single layer of glass outside the wall with an air space and sealed from the outside, but open top and bottom to the interior, and with a drain at the bottom for condensation to drip outside. The idea is for it to circulate warm air inside during the day, and at night circulate warm air in the top, condense water onto the glass and drip outside.

"best" solution is a water to air heat pump with air to air heat exchanger on the ductwork, hooked to the floor heating, but running AC with the heat exchanger for an extra low dew point. Sounds ridiculously complicated, but it's reasonable for the effect.

https://www.zerustproducts.com/prod...s-parts/toolbox-liners-toolbox-drawer-liners/

I have some zeo rust capsules in things but haven't really put them to a head to head test might be worth a try sometimes save the vci paper cat parts are wrapped too

Gun safe dehumidifiers are just a small heater that lets warm air circulate up maybe something could be done that way light bulb on the bottom of a cabinet or something

I was wondering if there might be something I could put in my toolbox to help keep it warm or dry. Trying to heat the whole shop would break me, especially with today's energy costs, that's why it's unheated. Some kind of small electric radiator in the bottom drawer might help?

You should only have to keep it a few degrees over ambient temperature.

And you only need the heat when it's damp outside, warmer than inside. Dew point is what matters.

Lots of materials will act as a desiccant. An unfinished wood cover for the tool box, that you could heat and dry out somehow, would be plenty to keep tools inside dry, especially if the whole works was covered with plastic. Silica gel is another common desiccant. Used to be able to buy a jug of silica gel cat litter. Fill an old sock with gel in each drawer, dry them out near a stove, or on a car dashboard in the sun.

Against my better judgement to answer a question.
When I worked construction {believe it or not} I used a magnetic oil pan heater at night placed
at the back bottom of my road chest. Zero problems with rust.

take it for what it's worth.

Half my stuff is in a trailer its a real pain. If i get my own shop i am going to build a tool room it will not be so bad if every thing is in a small space with a heater and a window. Then i can kind of control what is going on.

I have the same issue especially in the spring when the glacier starts melting and then during the summer when it gets really humid..The installation of a ceiling fan kept on low during these times helped out immensely and doesn't cost a whole lot to keep the sweat monster away.Ridge or gable vents allow moisture to escape pretty well..I also just hit the drawers with a little thrust now and then to keep everything shiny...

You could always try some desiccant bags, they are cheap and even come in some stuff you buy.

I work in a rainforest and my tools are always in slurry, dust, mud and water, things like black oxide prybars will rust pretty easily. Usually once a hitch everything in my tool bag gets a WD40 bath and it helps keep things rust free.

Only rusty tools I have come from garage sales. Like above use WD40 or something similar, always have some oil film on them.

My tools never stay still long enough to gather rust

I’ll second the magnetic block heater idea. They also work good to keep your steel work bench cozy.

redneckracin said:

Warm air touching cold surfaces causes condensation. You have to remove one of those items to prevent it. Don't forget if you are burning open flames inside, you are also creating moisture. I might try setting up an electric heater or vented fuel burning heater of your choice. That should help out a good bit with the moisture/excess moisture.

Click to expand...

I'll counter with cooling air can't hold as much water. Every 18 degree F drop in air temperature doubles relative humidity. Water coming from the air will separate most effectively on a surface.
Opposite is true of warming air. Your heated house in winter experiences both humidification from living things inside, and cold air infiltrating from outside. You want to keep a balance.
I believe best way to keep condensation to a minimum is to limit air entry when the air is cooling & ventilate when outdoor air is warming.

A heating system in the garage is a great way to cure the problem. Do not use a non vented space heater. Hydrocarbon fuel, (propane, natural gas, oil) all produce water as a byproduct of combustion. Vented to outside will warm the air, lowering relative humidity. The exhaust vented to outside draws in outdoor air to replace. The colder air coming in will warm & lower RH.
I once installed walk in cooler systems to use cold outdoor air instead of refrigeration in winter. It didn't matter in beer coolers, but the air brought in at any temperature below 32 F dried out produce. Some compensated by installing humidifiers.

Warming air causes evaporation.
Cooling air causes condensation.