Keeping dry atmostphere in workshop

[Hickorystick]

Hi
My almost completed workshop has insulation in the ceiling joists (flat roof) and plasterboard over.
The walls have OSB panelling. Ive noticed over the last week when the temperature has been really cold outside that the workshop has obviously been very cold also and after being in there for a little while noticed there was a slight film of condensation on some of the metal machine casings.
My obvious worry is that if this is constantly repeated throughout the winter I will end up with a film of rust on bare metal surfaces.
Anyone know how this can be overcome ? The workshop is not heated although I had toyed with the idea of a pot belly stove but that would only be lit when I was in it.
Is there something like a dehumidifier.... or something that works like Silca Gel ?
Anyone out there with a similar issue and solved it ?

Thanks
Phil

 

[woodpig]

I've had two garage workshops that were damp. The first one leaked air quite a bit which many say should help to keep condensation down, it didn't. The second only leaked air at the up and over door and was better. I now have a wooden cabin which has sealed windows and door with just a few tiny air gaps near the roof and all is well so far. I have bought an oil filled radiator to keep the damp at bay but haven't needed to use it so far. From what others have said unless you heat the space an electric dehumidifier won't work. You could try some of those crystal types. B & Q sell them along with tubs of replacement crystals. We've used them in damp cupboards before and it's surprising how much water they can collect.

 

[CHJ]

If you can provide a small amount of heat to your machine castings with something like a low wattage bulb or vivarium matt low down under them and cover the machines with a throw then as long as the metal is a degree or so above the ambient air then condensation will not settle on them.

More elaborate methods fix low wattage, low voltage supplied resistors to the machine beds and physically supply a heat source directly, but you need some electrical knowledge to do it safely.

My chuck/accessories cabinet has a 7watt bulb in it and all steel taken out feels warm compared with stuff out in the shop.

The steel window frames are the overnight cold sink in my shop and they accumulate the condensation rather than the lathes and tools in rack.

 

[Phil Pascoe]

If you fit a pot belly you'll cause more problems than you solve. I didn't have any rust at all until I used one.

 

[John15]

I seem to have very little problem with dampness in my small unheated (except when I'm in there) workshop. It is an all timber structure with double cladding, insulation and a plywood lining. I have removed the window, primarily for security but it also helps with keeping the place dry, and as an extra precaution against rust to my machine beds I periodically apply Liberon Lubricating Wax.

John

 

[Matt@]

to keep a workshop dry you need a dehumidifier - end of! They only cease to work if temperature drops to around freezing as I understand it, so stick an oil filled rad in there as well when its frosty.....

 

[Hemsby]

Humidity problems are all too common :x . My workshop has no insulation at all and I used to suffer bad problems with surface rust.

I purchased an EcoAir ECO DD322FW Desiccant Classic Dehumidifier that works down to 1 deg C and since using it the rust problem has completely stopped =D> . The only heating I use and only very occasionally for a short while before I start work is a fan heater (not while there is dust about, due to fire risk) other than that it is the Dehumidifier.

Although it only works down to 1 deg the workshop, even in the coldest winter the internal temperature has never dropped below 4 deg anyway.

Keith

 

[Matt@]

yes, dehumidifiers are amazingly effective. You can pulll out 5litres of water from the air every 24 hours - water that would otherwise have settled into the fabric and content of the building. Also because it removes moisture it makes the air seem warmer. And they cost no more than a fridge to run....

 

[n0legs]

I have a large commercial grade dehumidifier and have no issues with condensation or damp.
It's better than heating the workshop constantly to keep away the damp. It's on constantly and "plumbed in" so there's no buckets or tanks to empty.

 

[DennisCA]

As I see it, dehumidifcation is too difficult where it gets cold like here and I don't keep my shop at a temperature high enough to make it an effective proposition.

My plan is to have an air inlet and a heater to warm the incoming air. Heating the air increases its potential to hold moisture and it will absorb moisture from the colder air in your your shop and on surfaces. Then vent it via another vent somewhere else (opposite side of room perhaps, facing eastwards is preferable, or so I've been told), you can just have an heating element infront of the incoming air and rely on self-draught, or use a hot air fan.

Right now I just have an air space heater and the garage port isn't fully sealed so that is what has to allow for air movement. Not optimal but no rust issues in my shop. I plan to use a solar panel later to heat air to help warm and dehumidify air.

My garage is probably better insulated than most your houses are though...

 

[Jacob]

You can have passive dehumidification with single glazing fitted to allow condensation to drain off to the outside e.g. a gap at the bottom of the panes over a cill with a bevel, or moisture collection in a channel drained off to the outside.
It works very well on all my windows - you really become aware of how much water is extracted if the weep holes block and it accumulates instead.

 

[Yetty]

I've used an electric desiccant type dehumidifier in my workshop for years. Beforehand, the air was damp, steel rusted, and I was worried about the timber movement due to excess moisture.

These dehumidifiers work well at lower temperatures, and the heat produced is very welcome in the winter. A cheap hygrometer is useful for checking what is happening, as there are times when the dehumidifier isnt needed.

I don't operate the dehumidifier v24/7, just when a project is running or am preparing some timber before a project starts. If a project is underway, then often I run the dehumidifier mainly when the workshop is vacant, especially at night.

A nice side effect is that the workshop temperature tends to feel a few degrees warmer than it actual is.

 

[doorframe]

I keep my workshop heated 24/7. 1 fan heater, and a 12" fan on slow to help move the air around. Yes, it does cost money to run, but it's always warm enough to work in just a t-shirt, and it's worth it to me to have it comfortable in the evenings when I get home from work and all through the weekends.

Edit to add, it's a single skin wooden structure, and it's bone dry with no rust in the last 13 yrs since I built it.

 

[siggy_7]

See here for a description of fitting electric heaters to metal machines: tis-the-season-of-rust-and-mellow-fruitfulness-t55942.html I'm in the process of doing this at the moment.

 

[tomlt]

Look up rubydry dehumidifier, had mine 2yrs, works great in my 5.5m x 7.5m unheated garage, uses silica based technology rather than condensing so works down to low single figures no problem, also puts out a little heat, enough to keep my uninsulated building 4deg c above ambient.

Tom.

 

[wallace]

For the past few years I have been battling the rust monster on my machines I've tried most sprays to prevent rust but still had problems. A couple of months ago I got a cheap dehumidifier from a car boot. I have noticed a big difference to my machine surfaces. I have it set low and collect about 4lts a week

 

[DennisCA]

Oh yes one of my future plans is to use a home built solar catcher to warm and dehumidify the shop for free. Probably building it next year.

 

[Jacob]

Oh yes one of my future plans is to use a home built solar catcher to warm and dehumidify the shop for free. Probably building it next year.

It's called a "window".
Single glazed and drained if you want it to dehumidify. South facing for heat. The best design is the double sash - water drains off between the meeting rails and at the bottom of the bottom sash. But it doesn't have to be that complicated.

 

[KevM]

I'm toying with the idea of a dehumidifier, probably of the dessicant variety because of the background heat they produce and their ability to work to lower temperatures. There's a recent review of a bunch on the Practical Boat Owner website; an interesting snippet jumped off the page:

Desiccant dehumidifiers ... require operation in air free from solvents. Solvents (from resin or varnish) can affect the desiccant.

From what I've read all the dessicant humidifiers seem to share a common technology in their zeolite dessicant disc, so it's probably worth bearing in mind if you use solvent based finishes.

 

[Benchwayze]

I must be lucky. I never had a problem with condensation in the workshop.

However, I use a single-garage, integral with the house, so I don't need much heating. Also the metal, up and over door, is due-south facing. Only on the coldest days does it feel chilly to the touch, and I can work in there with the door open all the year round. So I assume the door acts as a convector, whenever it gets the slightest sun on it. It gets darned hot in the summer mind! (hammer)