Humidity??

Roger Pozzi

Member
Messages
75
Location
Mount Vernon, Ohio
I didn't know where to post this so, it's here unless the mods want to move it.
My shop is a 10X16 wooden shed and I'm lucky enough to have electricity in it. I'm basically limited to propane heat right now and have been using a Big Buddy heater with success. But, with the heat comes too much humidity causing rust on all cast surfaces and steel tools in drawers. I guess that cancels the previous statement about success. :eek:
My question is, has anyone else had to deal with this problem? Will a small (how small) dehumidifier help?
I have a very limited budget so I'm looking for relatively inexpensive solutions, if those exist. What the local professionals (?) suggest would take me over a year to pay for, so there would be no need for the shop by then.
Thank you in advance for any and all expertise shared here. :thumb:
 
Roger I have lived through your experience and the only solution i found was to move my tools into the basement for winter and leave the rest to be as the weather sought to make it, making sure to put a good layer of wax on things such as cast iron surfaces.

Its more than just the humidity. What is happening is that you heat up the shop and it heats up the tools given they metal when the heat is over and the air cools it results in condensation on all the prior warmed up tools and thats when our buddy rust comes out to play.

My first winter i tried heating the very airy garage i moved to, i managed to make it bearable to work in but it was not while working that the issue came on. It was after when the cold nights came and those warm tools got saturated in moisture.

Unless you can keep the heat on all the time and insulate the shop there is no winning this one.

At my prior home i had a shop that was fully insulated. I had a overhead radiant tube heater connected to natural gas. I set it to run such that it kept the temps above freezing when i was not in the shop and it did not take much to warm up the place when i was in it. But it was insulated to R22 with 6 inch stud bays etc and double pain gas filled windows. Never had rust problem in there and in summer i ran a small aircon to keep the humidity down.

Moving my tools in doors has been a pain in the rear big time because in summer i have to move them out again but dont. It means i migrate them bit by bit as needed through the summer.

So i dont know if there is any real solution other than a sealed up always heated in winter shop.
 
Not disagreeing with Rob, but I can't help but wonder if using an electric space heater would help. Of course, that would assume you have enough electric to run it. But if you have power for a dehumidifier, you can probably run a heater.
 
Both of those responses are correct. You want to keep a fairly consistent temperature and that temperature needs to be above the dew point. If you can keep the temperature say 50F with electric and heat it up to 60-65F when working with propane it should be better. Also, since the propane heater you are using is not vented, it is adding a lot of humidity as well since water is a byproduct of the combustion. If you could go to a little direct vented propane heater it would help the humidity in the shop and lower the dew point! Depending on your propane source you could let the vented propane maintain the minimum temp if you want.
 
It addition to what has been said, waxing surfaces and keeping things well lubed can go a long way. My shop is not climate controlled at all and I've not had any issues with rust here in the midwest. For surfaces, you can also keep an unfinished piece of underlayment on them to prevent any condensation from sitting on the metal, as it will wick away the moisture. I have my dad's saw that I used growing up which he always kept with a piece of underlayment on top when unused. The top looks mostly new, no pitting or surface rust. This was his main job site saw when building houses, so it's seen many years of use out in the elements. I mostly just use wax on my tops and have had good luck though.
 
Just thought of something else, maybe some VCI paper in drawers with bare metal tools? I don't know how effective they would be on tool slides or larger surfaces out in the open but it works well in other applications!
 
Not disagreeing with Rob, but I can't help but wonder if using an electric space heater would help. Of course, that would assume you have enough electric to run it. But if you have power for a dehumidifier, you can probably run a heater.

Yes, electric is available but, expensive to maintain the minimum heat in my shop.
 
Both of those responses are correct. You want to keep a fairly consistent temperature and that temperature needs to be above the dew point. If you can keep the temperature say 50F with electric and heat it up to 60-65F when working with propane it should be better. Also, since the propane heater you are using is not vented, it is adding a lot of humidity as well since water is a byproduct of the combustion. If you could go to a little direct vented propane heater it would help the humidity in the shop and lower the dew point! Depending on your propane source you could let the vented propane maintain the minimum temp if you want.

You hit on my thought. The humidity mostly comes from the heater which leads me to believe that a dehumidifier running along with the heater may help. It's just too costly to try without more knowledge about it.
 
Rob, I appreciate your thoughts but, I really have to disagree with you to a point.
What I had noticed last year was that the condensation occurred while the heater was just getting started to raise the shop temperature. The reverse of what you stated, if I understood you correctly.
That is what led me to believe that my problem was being created solely by the heater therefore fixable.
 
You hit on my thought. The humidity mostly comes from the heater which leads me to believe that a dehumidifier running along with the heater may help. It's just too costly to try without more knowledge about it.

Be on the lookout for a vented heater. That solves a heap of your trouble. A dehumidifier will be hard pressed to keep up with the moisture that heater cranks out plus it burns through electricity. Good luck, let us know what path you take!
 
Rob, I appreciate your thoughts but, I really have to disagree with you to a point.
What I had noticed last year was that the condensation occurred while the heater was just getting started to raise the shop temperature. The reverse of what you stated, if I understood you correctly.
That is what led me to believe that my problem was being created solely by the heater therefore fixable.

He was right in that condensation on things below the dewpoint are an issue. The factor that isn't usually considered is the high amount of water vapor in flue gas that's the byproduct of the combustion. When you crank up your heater you're dumping water into the room and the cast iron pieces are cold. While the increased temperature lowers the relative humidity helping the dew point problem, the addition of water drives it right back up so it's a race that apparently condensation is winning.... lol

BTW, my wife won't talk about humidity any more. She once asked me to explain relative humidity to her..... Her eyes glazed over and we've not been able to discuss the topic since. :rofl:
 
Years ago I had humidity problems. That was when I had an un-vented natural gas shop heater.

For several years now I have had electric radiant heaters. That spot heating is OK, but not as good as a heated room. AND electricity is very expensive in Southern California. When I first started using the heaters my electric bill went up over $100 per month compared to the previous year.

Enjoy,
JimB
 
Both of those responses are correct. You want to keep a fairly consistent temperature and that temperature needs to be above the dew point. If you can keep the temperature say 50F with electric and heat it up to 60-65F when working with propane it should be better. Also, since the propane heater you are using is not vented, it is adding a lot of humidity as well since water is a byproduct of the combustion. If you could go to a little direct vented propane heater it would help the humidity in the shop and lower the dew point! Depending on your propane source you could let the vented propane maintain the minimum temp if you want.

I use a Goldenrod Dehumidifier in my tool box to keep the temperature around my hand tools above the dew point. Seems to work well. It is basically a heater. You could probably do the same thing with a heat lamp, but this is safer. It is quite often used in gun safes. Of course it only works in closed spaces. Not a whole shop solution.

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Be on the lookout for a vented heater. That solves a heap of your trouble. A dehumidifier will be hard pressed to keep up with the moisture that heater cranks out plus it burns through electricity. Good luck, let us know what path you take!

That was my thought on recommending the electric heater.....the dehumidifier is also expensive to run. Admit tingly, not as much as a heater, but probably somewhere near the 1/2 way point. Like Robert said, it will struggle to keep up as well.
 
I've had several shops in all climates and humidity is always a problem. The single most important problem is insulation. The shop has to be tight. Opening and closing doors allows moisture in, and even bringing in moisture filled lumber as well. In order for a humidifier to work...the shop has to be tight because the humidifier will pull in outside air through cracks, plus...most humidifiers won't work under certain temperature levels. Store lumber near the ceilings because heat always rises and hangs there until cooled, then falls. It will dry quicker and the sooner it dries, the drier the shop air will be. A wood fire in a shop, I found to be the best for removing moisture.
 
Insulate and radiate. Sounds like you are looking for a temporary solution, since you said you wouldn't be needing the shop in a year? In that case, I would keep my eye out for used insulation...maybe check with local renovation contractors, Craigslist or Freecycle. Get that ceiling/roof insulated well, then do the walls. Pick up one of those oil filled electric radiator heaters at the second hand store and set it to keep things above freezing. Try it for a month to see what the cost of operation is. If you get enough insulation in there it shouldn't cost a lot and might work.
 
The problem is the unvented propane. It is the cause of your humidity. I have an unvented propane fireplace that I use especially during power outages and it adds so much humidity to the house that it gets really uncomfortable.
My shop is in my basement and the only time I have a moisture problem is in the late summer when the weather gets a bit humid. I run a dehumidifier during the months of July and August (on low) and it adds about $25.00 a month to our electric bill (we have some of the highest electric rates in the US).
No problems with rust at all.
I've been planning on moving my shop to my 2 car oversized garage. and have been saving up for the electric work needed. When I do I will install a pellet stove or a small wood stove to keep it warm. Maybe a small pellet stove would work for you??
 
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