Moisture on tools when heating shop

[Mike Harvey]

My shop is my 2 car attached garage that is not insulated yet. Noted for the first time some of the tools in my tool boxes having a layer of condensation on them
after having warmed up the garage with my 40,000 BTU LP heater and then had my 23,000 BTU Kerosene Home Heater running to keep it warmed up as don't like all the noise of the force air fan in the LP heater.

This was the first time I had noted it doing this but don't want to have something start rusting all my tools.. What is the best way to prevent this.
Got too much $ tied up in tools to cause them to start rusting..

Looking for tips and tricks to prevent this from becoming a major issue.. Thanks

Mike
Near St Louis Mo

[George Bokros]

Not sure how to prevent it. I comes from the cold tools condensing the moisture in the warmer air. I had that happen to some new brake rotors when I did a rebuild on the suspension and brakes on my toy a few years ago. We had a warm day and I opened the garage door and they flash rusted. Not a problem on brake rotors but on tools it is a problem.

Actually I do not think there is any way to prevent it short of heating the garage all the time.

[Dick Mahany]

Johnson's paste wax is your friend. Use it and use it often in those conditions. It won't completely prevent rust, however it will greatly inhibit it if you keep an eye on it. My LP heater does the same thing and Johnson's definitely helps.

[John Schweikert]

I had the same issue using a Propane heater in my shed. My bandsaw and jointer cast iron rusted in just a few days.

My solution was to insulate with R-13 which cost about $300 and now I use a 1500 watt Lasko electric heater. Even when it was 5 degrees here this week. I could get the shed almost 60 degrees inside. I have a bow roof shed 12x24 in size with full joist and plywood floor.

Type of heater I use: http://www.homedepot.com/p/Lasko-23-in-1-500-Watt-Electric-Portable-Digital-Ceramic-Tower-Heater-with-Remote-Control-5160/202295960

Dry heat is important. Heating with propane or kerosene can easily result in rusted tools.

[Mike Harvey]

Dick, I do use Johnsons paste wax on my table saws and band saw tables, but where I noted it was I opened my craftsman tool chest and noted moisture on the top of many of the wrenches and stuff in the doors. I also keep my air nailers
and air tools in some of my tool chest drawers so don't want to have them start rusting from moisture being created.. Does anyone know if slowly bring up the heat in the garge would stop it since that day it was very cold
out (we just got 15 inches of snow a day or two earlier) so it was around zero so I cranked up both heaters to warm up the garage.. Was not sure if the heat coming up fast might be what caused it or just any heat that
is not dry. Have had both heaters now for a few years and this was the first time I had noted that happening.

[Bradley Gray]

The LP and kerosine heaters, if they are unvented, put out a lot of moisture, so that may be part of the problem. I have a face jointer and planer in an unheated space and when the air is warmer than the cast iron I get condensation. When this happens I use a fan on the machines and evaporation wins, so maybe a fan would help - cheaper than constant heat!

[John Schweikert]

Yes, fast heating is mainly the culprit here. But I've never found a slow way of heating up the shop with the propane heater I had.


Dick, I do use Johnsons paste wax on my table saws and band saw tables, but where I noted it was I opened my craftsman tool chest and noted moisture on the top of many of the wrenches and stuff in the doors. I also keep my air nailers
and air tools in some of my tool chest drawers so don't want to have them start rusting from moisture being created.. Does anyone know if slowly bring up the heat in the garge would stop it since that day it was very cold
out (we just got 15 inches of snow a day or two earlier) so it was around zero so I cranked up both heaters to warm up the garage.. Was not sure if the heat coming up fast might be what caused it or just any heat that
is not dry. Have had both heaters now for a few years and this was the first time I had noted that happening.

[Lee Schierer]

The LP and kerosine heaters, if they are unvented, put out a lot of moisture, so that may be part of the problem. I have a face jointer and planer in an unheated space and when the air is warmer than the cast iron I get condensation. When this happens I use a fan on the machines and evaporation wins, so maybe a fan would help - cheaper than constant heat!

The moisture produced by the heaters is the major cause of condensation on the cold items in the shop. My Dad had a shop heated by a wood stove and even when temps were near zero when we started working in his shop, the heat from his wood stove never produced condensation on an of the cold iron. Switch to a vented heater (conventional furnace) and you won't be sucking up the CO-2 as well as having moisture problems. Ever have a headache after working in your shop? If so CO and/or CO-2 is the cause for your headache.

[Mike Kelsey]

Clear plastic shower curtain. Really works! My shop is an old barn I've been working on winterizing for ages. While still uninsulated and darn cold and damp in the winter, my wife bought me several inexpensive clear and quite pliable shower curtains which I just loosely drape over the table saw, drill press,tool cabinets,etc - rust problem gone. And did I have rust problems before that :-(

[Ray Newman]

My propane heater vents outside; however before building the new shop, I worked in an unheated garage. moisture and rust were always a problem.

Johnson's Paste Wax is a 'gawd-send' and prevents rust. I also covered -- and still do-- my tools wit HTC Tool covers, form Woodcraft. The covers repel moisture ad yet allow the material to "breathe" , thus preventing moisture build up on the metal. Well worth the cost.

http://www.woodcraft.com/Product/2004382/17473/Jumbo-Power-Tool-Machine-Cover-72-x-112.aspx

[Jeff Erbele]

Water vapor is a by product of combustion, especially with LP. As already mentioned, a vented heater would help.

Uncertain, is if the condition previously existed and you just noticed it, or if it started recently. If it existed previouly and frequently chances are great that even if you did not notice the condensation, rusty tools and machines would have been apparent.

If it just started, who knows why for sure, but perhaps the circumstances are ideal , mainly the dew point.

I don't know that warming your shop up slowly is going to help and all. Doing so will produce the same result at a slower pace. Electric heat is a dry heat but may be costly depending on your rate.

In years past, i owned a house that had a damp basement in the summer. I bought a fairly large dehumidifier. It solved the problem but used a lot of electricity and threw off a lot of heat, which was not desirable in the summer, the only time of the year I needed it. Eventually I had a central A/C installed and that solved everything.

So what should you do. I think the vented heater suggestion is the solution. You could also maintain the garage at above freezing but without insulation that too could be expense. No matter what you do, I would place a priority on insulation of you use and heat the garage on some frequency.

Otherwise take rust preventative measures, oil and paste wax. Keeping your tools in wooden tool boxes, your machines covered and everything well oiled would help greatly.

[phil harold]

The LP and kerosine heaters, if they are unvented, put out a lot of moisture, so that may be part of the problem. I have a face jointer and planer in an unheated space and when the air is warmer than the cast iron I get condensation. When this happens I use a fan on the machines and evaporation wins, so maybe a fan would help - cheaper than constant heat!

I keep a ceiling fan on in my shop 24/7
Propane unvented is bad

Insulate your shop, you will reap the benefits all year

[Jim Neeley]

One molecule of Natural Gas (chemical formula CH4), combusted cleanly, reacts with oxygen to form one molecule of CO2 + two molecules of H2O.

One molecule of Propane (chemical formula C3H8), combusted cleanly, reacts with oxygen to form three molecules of CO2 + four molecules of H2O.

With either fuel, if you are not venting the vapors you are releasing warm (hot) CO2 and water vapor into your shop. If there are cooler surfaces (walls, tools, etc.) nearby, the water vapor will condense on them once the moisture content of the air approaches what would be 100% relative humidity for the tool temperature.

If you are having a problem with rusting them you are releasing too much water into your room air and venting the exhaust outside is the best solution. You can mitigate the effect by waxing, which won't affect the condensation but as long as the wax is covering the surface completely and doesn't get worn away from use, may prevent the rusting. Forgetting to apply it frequently enough to keep the water molecules from getting to the iron molecules will cause rust.

Jim

[Mike Harvey]

it was not on my bigger tools that I noted the moisture, but on hand tools and air tools in my tool chest.. Got (2) table saws and (2) band saws out on the shop but keep them coated pretty good with Johnsons Paste wax.
But the ratches and wrenchs I noted the moisture on were in the end of the shop closest to the garage door. Hope to be able to get it insulated atleast in the ceiling this spring.

Has anyone ever added insulation to an existing steel garage door. Have seen some foam with a shiny side that I read one article that it might work good for just that purpose.
Just scared of adding much weight to the door and straining the garage door opener. Not sure how much weight you can safely add to one without risking damage to the opener.

But thanks for all the suggestions. I think I will mostly use the Kerosene Home Heater and perhaps sell off the LP heater. Never have liked the loud noise from it but
the heat it puts out does warm up the shop much quicker on the really cold days.. But suspect that may be the cause of the problems..

[Jason White]

http://www.sawmillcreek.org/showthread.php?212495-Getting-the-rust-off&p=2207465#post2207465

[Jim Andrew]

This problem has completely gone away since installing an outside wood burning furnace. Guess the air movement and heat have dried the shop out. I don't heat unless I am there, and the temps get down near freezing at times. Of course, we have had outside temps very low as of late, thanks to insulation my glue has not frozen.

[Steven DeMars]

Insulation, fan & an ELECTRIC HEATER . . .

[jim gossage]

Fine Woodworking did a scientific review of 20 or so "rust preventers" in July 2012 and found that CRC 3-36 and Moovit were the best. WD40 was pretty good too. Boeshield and paste wax were only slightly better than no prevention at all.

[phil harold]

Fine Woodworking did a scientific review of 20 or so "rust preventers" in July 2012 and found that CRC 3-36 and Moovit were the best. WD40 was pretty good too. Boeshield and paste wax were only slightly better than no prevention at all.

I like slipit for lubrication not great at rust resistance
I read some guy used spar varnish, I suppose it could seal the pores of the cast iron


Sparring with tool rust
When I turn on the heat in my uninsulated shop, you can almost watch the rust form on the machined surfaces of my tablesaw, jointer, etc. I tried commercial rust preventers, but they didn't last long or transferred to my project materials. Purely by accident, I found that spar varnish, sprayed on my machine table- tops, effectively prevents rust. After a light sanding with 400-grit paper, the surfaces are shiny and smooth, with no transfer to my workpieces. It's been more than 6 months since the treatment and I've not seen a speck of rust.

Here is some test results for a from boat forum on fresh/salt water resistance



Metal Maintenance: 12 Corrosion Inhibitors (Salt Water) Tested

What keeps corrosion at bay best in the marine environment? We found out by testing a dozen corrosion inhibitors, including products from well-known names such as CRC, WD-40, LPS, and Boeshield. One of mankind’s greatest early achievements was the extraction of pure metal from rock. The process takes ingenuity and consumes vast amounts of energy. So it is with considerable frustration that we watch nature so easily reclaim what we have wrought at such cost. Few are more familiar with corrosion than mariners, who fight a constant battle against it in the salty interface between sea and sky.

Each of the test products was applied to two mild steel strips—one to be suspended in salt water and the other to be sprayed with fresh water. The strips pictured here are post testing; the left strip of each pair is the freshwater panel.
A visit to the hardware store or a search on the Internet reveals no shortage of products to address, and even redress, corrosion—most are touted as being able to penetrate ("frees rusted parts"), lubricate, or protect electrical components. Here we examine the corrosion-inhibiting properties.

What We Tested
We chose the products based largely on their advertized claims and also on how easy they were to find. Several are available in hardware stores. West Marine carries its private-label product, CorrosionPro Lube, as well as CRC Heavy Duty Corrosion Inhibitor, Corrosion Block, Boeshield T-9, and WD-40. CorrosionX, Shark Hide, the LPS products, and TC-11 all popped up during Internet searches. We left out products that made no specific claims for use in the marine environment. Anything that had "rust" and any reference to "marine" or "boats" or "salt spray" was fair game.
Twelve made the roster: PMS Products’ Boeshield T-9; LPS Laboratories’ LPS 1, LPS 2, and LPS 3; Corrosion Technologies Corp.’s CorrosionX and CorrosionX HD; ICC Industries’ TC-11; Lear Chemical Research Corp.’s Corrosion Block; West Marine’s CorrosionPro Lube; CRC Heavy Duty; Shark Hide; and WD-40, because it was already in the workshop.
Each showed different degrees of viscosity, all went on wet, and most stayed wet, or at least tacky. Those that left a waxy coating performed the best in the saltwater test.
None is pleasant to use and all of their containers carry stern warnings about flammability, use in poorly ventilated areas, and against inhaling them. Most use heavier-than-air butane, pentane, or heptane, or a mixture thereof, as propellants, which means there’s a risk of an explosive mixture accumulating in confined spaces such as bilge compartments. Ventilate these areas throroughly before operating anything that might create a spark.
The LPS products use carbon dioxide as propellant, and Corrosion Block nitrogen, but the solvents are still flammable.

Boeshield T-9
According to its maker, Boeshield T-9 is designed for penetration, moisture displacement, lubrication, and rust and corrosion protection. Heavier than some of the other sprays in our test, it dries slightly tacky.
The T-9-coated strip sprayed with fresh water was rust-free after a week. The one submerged in salt water had rust around the screw and at the top after three days. The trend continued through eight days, with more corrosion on the cured side (see sidebar above) than on the uncured side.
Bottom Line: In terms of what our test covered, T-9 works as advertised, even in salt water. Slightly more corrosion at the screw and price edged it out of the top three.

Corrosion Block
Advertised as a corrosion preventor and inhibitor, Corrosion Block is a heavy, blue spray that dries thin, clear, and slightly tacky.
After seven days of freshwater dousing, the Corrosion Block-coated strip showed some rust spots at the top, where we’d expected a thicker coating. The saltwater strip, however, was very rusty after three days—except for an area toward the top. After eight days, it had rust all over it.
Bottom Line: Corrosion Block is OK for freshwater purposes, but not salt water. To be fair, the manufacturer makes no claim regarding rust.

CorrosionPro Lube
West Marine claims its product offers "...excellent water resistance and superior rust and corrosive preventative characteristics." And it does.
This fine spray leaves a visible, amber-colored, waxy coating. The coating remained intact through a week of freshwater dousing, and the metal strip showed no signs of rust. The saltwater strip saw similar success: The coating remained after three days, and there were no signs of rust. It was only after eight days of saltwater abuse that some rust appeared along the "uncured" edge.
Bottom Line: This product does what it claims. The waxy film isn’t pleasant to the touch, but for hard-to-reach parts, it’s on the money.

CorrosionX
This aerosol, which makers claim provides protection against rust and corrosion, initially forms a foamy, blue-green film. The bubbles eventually disappear.
CorrosionX’s freshwater performance was excellent: After seven days, there was no rust and the film was still tacky. (So sticky, in fact, that a few small flies met their end on the metal strip.) Unfortunately, its saltwater efficacy rated at the other end of the spectrum. After eight days, except for a band at the top, the metal strip was very rusty, and particularly corroded around screw.
Bottom Line: CorrosionX works fine in a freshwater environment, but it’s not ready for brine time, especially in a mixed-metal situation.

CorrosionX HD
Think of this as CorrosionX’s big brother: A "high-performance, thick film version of CorrosionX," according to Corrosion Technologies Corp. It comes out as a fine spray with some bubbles and a thick, amber color.
Like its sibling, we rated it Excellent in the freshwater test, but it wasn’t up to the challenge of salt water. The strip in saltwater had a rusty bottom half and a less-rusty top half, almost in proportion to the thickness of its coating. A clear halo appeared where the product accumulated around the nut, and curiously, less corrosion formed on the "uncured" side.
Bottom Line: The sticky film does resist freshwater penetration, but it isn’t immune to salt water, especially for the long term.

CRC Corrosion Inhibitor
CRC Heavy-Duty Corrosion Inhibitor, which is seemingly identical in appearance and performance to CorrosionPro Lube, is made for saltwater use. It claims to protect and preserve metal surfaces subject to salt spray and high humidity. It comes out as a fine spray with a thick coating.
The freshwater test strip still had a sufficient coating and no rust after seven days. It was equally impressive in the saltwater test: coating intact and no rust after eight days.
Bottom Line: Excellent performance. It lives up to its claims.

LPS 1
LPS Labs offers three products with three levels of rust protection. LPS 1 is marketed as a greaseless lubricant that displaces moisture. Colorless, it has a broad spray range.
In the freshwater test, the LPS 1 panel only had some rust on the uncured side after a week. After three days in salt water, the strip was very rusty, except at the top, and by Day 8, it had rusted all over. The brass screw also showed signs of rust, as though iron were being transported to its surface by galvanic action, there to repeat its demise (just a guess).
Bottom Line: LPS literature says the product displaces moisture on electronic components and that its light, greaseless film inhibits corrosion. It doesn’t claim to prevent rust, but it works for fresh water, if given time to cure. The broad spray pattern made it difficult to concentrate the product where it was wanted.

LPS 2
LPS 2 is touted as a multi-purpose lubricant and penetrant with added corrosion protection. It’s a colorless, fine spray with a strong almond odor and broad spray pattern.
The freshwater LPS 2 panel had no rust after three days, but some after seven days; more on the "uncured" side. After three days, the saltwater test strip exhibited extensive rusting, and after eight days, it was completely corroded.
Bottom Line: LPS 2 claims to provide protection indoors for a year, and its performance indicates that as its limit. It is not useful in salt water.

LPS 3
The strongest of the LPS series, LPS 3 claims to be a long-term, heavy-duty rust inhibitor, even in the harshest environment. Its bubbly, thick spray forms a waxy, pale brown coating.

The CRC spray (left) is the least expensive of the three products that showed no rust in saltwater. The CorrosionX HD saltwater panel (right), like several other test panels, had more rust on its bottom half than its top half, and oddly, it had less rust on its “uncured” side.
After a week of freshwater exposure, there was no sign of rust and the coating was still tacky. And even after eight days of saltwater torture, the LPS 3 panel showed no sign of rust and it was still very sticky.
Bottom Line: We tested it under "harsh conditions," and it does what it claims—but it’s not pretty.

Shark Hide
Shark Hide claims to be a protective coating against weathering and salt spray. Marketed mainly to owners of aluminum pontoon boats and similar craft, it lists steel among the surfaces it can be used on.
Unlike the other test products, Shark’s Hide is a thin, colorless liquid—not an aerosol—that wipes on with soft cloth. It’s a thin liquid, and has really nasty solvents (toluene and xylene)—so be sure to apply it in the open air and wear gloves.
The freshwater test strip showed rust spots on the "uncured" side after three days. But there was no rust on the cured side, even after a week.
The saltwater panel’s uncured side was rather rusty after three days, but the other side had only mottled rust. Even after eight days, the coupon wasn’t completely rusted.
Bottom Line: Shark’s Hide works well in fresh water when allowed to cure. And it performed better than expected (Fair) in salt water for having such an invisible coating. It’s easy to apply to large, smooth surfaces, less so to small parts like nuts and bolts.

TC-11
TC-11 is the "complete answer for rust control," according to its maker. The bubbly, blue-green spray forms a thick coating that was still sticky after a week of freshwater exposure. It kept the freshwater panel rust-free after seven days.
The saltwater panel did not fare as well: After three days, it had extensive rusting, and after eight days, only the very top was rust-free.
Bottom Line: This product isn’t the silver bullet—but it works in fresh water.

WD-40
Nearly as ubiquitous as duct tape, WD-40 claims to protect against rust and corrosion.
Although the fine, colorless spray’s coating was dry after a week of freshwater sprays, the panel had no rust.
However, after three days in salt water, the metal strip was completely rusted, except the top. After eight days, only the very top was showing resistance.
Bottom Line: This product works well in fresh water—and makes no greater claims.

Conclusions
Our salt water test is admittedly harsh, and quickly produced results. After three days, most of the steel coupons were significantly rusty. Only three saltwater test panels showed no corrosion: Those coated with CorrosionPro Lube, CRC Heavy Duty, and LPS-3.

Of the remainder, the Boeshield T-9 panel showed the least corrosion, followed by the cured Shark Hide. (The cured vs. non-cured results support the notion that it pays to follow instructions. Most non-cured sides mimicked the control panel.)
In the freshwater test, the Shark Hide remained rust free. It might be the answer for stainless steel rigging, stern rails, etc., because it leaves no sticky residue—however, it’s an expensive solution.
At 63¢ per ounce, CRC gets the Best Buy nod. For day-to-day use, loosening sticky mechanical parts, or softening greasy deposits, WD-40 works and is inexpensive.
In our opinion, the perfect solution still evades us. Where iron-based alloys are unavoidable and stainless steel isn’t suitable, the best protection against the ravages of salt water is a coat of paint.
Where paint isn’t an option, long-term protection against rust requires the use of sticky, dirt-attracting coatings, like the top performers in this test.



maybe varnish is the best bet

[Jim Andrew]

Has anybody used spar varnish? That would be near a permanent coating, although it would wear. Wonder how it would work in your slot for miter gauge? How about the color of your table tops?

[Doug Ladendorf]

Good info here. I had a flash rust episode this winter when I had to open the garage door for something on a warm day. What a pain. I'm now working my way around the garage to insulate. I found that my jointer, with a vinyl cover was OK except for the tips which didn't make it under the cover. I will be looking at the magnetic top covers for a couple key machines and trying to keep most tools in cabinets.
Doug

[Gregory Peterson]

(1) Insulate.
(2) Use a dehumidifier.
(3) Only used vented / forced air heating.
(4) Ceiling fan or other method to keep air turning over.

[Steve Milito]

Combustion reactions convert hydrocarbons into CO2, H2O, and heat. Unless you vent the H2O out of the shop you raise the humidity along with the temperature. Electric heat, on the other hand, only raises the temperature of the air and thus lowers the relative humidity.

[Ty Williams]

I wrote this in response to a VERY similar post on another forum, so if a few of the things I say seem to be speaking to someone else, well, they are :lol:

williaty, on 08 Jan 2014 - 5:07 PM, said:

As others have sort of tangentially mentioned, the problem isn't how you're heating the shop, it's the amount of temperature cycling you're going through. When the shop is unheated, the air cools, which lowers the amount of water it can hold. The effect of this is that it raises the dew-point, which is the temperature at which water vapor will condense out of the air. Eventually, the temp of something in the shop falls to the point that it is at the dew-point and water begins to condense. If the air is cooling faster than the objects in the shop, you'll get fog or rain in the shop (yes, I've actually seen this happen) that will eventually end up on your tools. If the tools are cooling off faster than the air (due to radiation, so this is unlikely since you have a roof), the tools will eventually drop to the dew-point and water will condense directly on the tools. When you warm the place back up in the morning, the amount of water the air can hold increases as the air warms, which sounds like a good thing. The problem is that the air's relative humidity is dropping, which increases the rate it absorbs moisture from vapor sources like your lungs (you're probably a bigger source of moisture than your heater), any kind of flame in the shop, or moisture migration through your slab and walls. You're heating the air, and adding water to it, faster than you're heating the tools. At some point, the dew-point rises to above the temperature of the tools and water condenses on the tools. This is what you're observing as you heat.

So what's the solution? You have two choices: 1) you can reduce the thermal cycling. Basically, make the day and night temperatures closer to each other so that the tools don't end up below the dew-point as you're trying to warm your shop. 2) You can control humidity directly. Going to a vented heater would help some, but I'm pretty confident you have other, larger sources of moisture. You need some way to pull the moisture out of the air. You'd need a real dehumidifier, not something you can get at the local big box store. Something like the Sante Fe Compact2. However, keep in mind that humidity changes about 2% for every 1* Fahrenheit change in temperature. So even if you pull the relative humidity down to 30% (which is quite hard to do, verging on impossible, with only a dehumidifier), that means you can never get the shop air temp and tool temp more than about 35F different from each other. If you're trying to end up with a 70F shop to work in, you can't let it get colder than 35F at night, which it's doing for much of the country right now. So that sort of leads you back to option 1.