Crazy humidity today

[Sideways]

It has been cold in our neck of the woods recently.
Sub zero for pretty much a week on end and the snow on the garden and ice on the roads of our estate only just melted.
My wife mentioned that it felt really warm out this morning.
The front door sticking was a warning.
I went into the workshop which is uninsulated and draughty to find condensation running off all the cast iron.
I've slapped the dehumidifier on with an 8hr timer and closed the door on it. The humidity read 99% !

This isn't the first time I've ever seen this but it's as bad as it ever gets.
Thank goodness most of the tools are in boxes !
Anyone else seen this as the freeze ended ?

 

[Tris]

Condensation on the outside of the door glass as I went to lock up last night about 10. That's a first here, and a sticking door this morning, normally only sticks when the sun gets on it but no danger of that today

 

[Argus]

Regardless of the perceived humidity, which is relative to the air temperature, the increase in air temperature from a prolonged ambient temperature likely to be below zero, has resulted in your metal tools being below what is termed the Dewpoint.

This is the temperature at which any moisture in the air will condense.
This in turn will combine water and oxygen with ferrous metal resulting in RUST.
If your tools have been in a cold ambient, followed by a rapid warming, they will attract condensation.

Seriously, my advice is to dismantle every tool, warm them, dry them all thoroughly and get some oil onto the surfaces.
Don't wait for the rust to be visible - it is already there. Boxes will offer very little protection.

There was a discussion on this subject a while back and I wrote an explanation of the process, how it happens and how to measure it:

https://www.ukworkshop.co.uk/threads/wet-and-dry-a-little-bit-of-measuring.126919/
Good luck

 

[Spectric]

Your cast iron has not warmed up as fast as the surrounding air, one way to help protect cast iron beds etc is to make a protective wood cover that keeps the warmer air off the colder iron. This humidity could be a new thing because the temperature swing of 15° literally overnight is amazing, if it had warmed up more gradual then there would have been less temperature difference and less problems.

 

[Fitzroy]

Car park ceiling was dripping due to the condensation, concrete still very cold to the touch and the warm moist air resulting in it raining in the car park.

 

[Argus]

The car-park ceiling here is a visible example of the effects of the Dewpoint of the atmosphere...... Dare I say, metal tools in unheated workshops will be another.

The Relative Humidity (RH) which we are referring to is an inverse value.
Without any other influences, an increase in measured Dry-Bulb ambient temperature will result in a reduction of measured Relative Humidity for no change in moisture content or Absolute Humidity.

However on the other hand, if a surface there (the car park roof or some metal tools) is at or below the Dewpoint temperature for that particular air-condition, the influence of condensation takes place ............and you've now invented the dehumidifier.
The RH value will now drop.

 

[Stuart Moffat]

… makes a mental note not to open both ends of my workshop to get warmer air in it. Mine is well insulated and low humidity in there yesterday, but have made the mistake before of opening it up, only to watch a low RH shoot upwards.

 

[Sideways]

I keep as many of my tools as I can in airtight dewalt toughboxes / the original systainers and L-boxxes, all with big bags of silica gel.
There's less I can do about the machines. Synthetic blanket throwovers usually help but for the metal lathe and drill press I'm crossing my fingers that being fairly well wiped with way oil will help.
Once it dries out it may be worth setting a high threshold of say 85% humidity and leaving the dehumidifier on automatic all the time to prevent this happening again.

It really shows up the impact of temperature because humidity was down at just 60% a few days ago while it was down in single digits.

This is normally a problem I associate with early spring.

 

[Phil Pascoe]

Only 94% here, but rising later.

 

[D_W]

It has been cold in our neck of the woods recently.
Sub zero for pretty much a week on end and the snow on the garden and ice on the roads of our estate only just melted.
My wife mentioned that it felt really warm out this morning.
The front door sticking was a warning.
I went into the workshop which is uninsulated and draughty to find condensation running off all the cast iron.
I've slapped the dehumidifier on with an 8hr timer and closed the door on it. The humidity read 99% !

This isn't the first time I've ever seen this but it's as bad as it ever gets.
Thank goodness most of the tools are in boxes !
Anyone else seen this as the freeze ended ?

it can happen here from time to time, but usually when the water table gets up and a weather change goes along with the floor expressing moisture.

I no longer have many power tools, and none with cast table tops, so the flash rusting is minimal. Surprise rust on the bandsaw and tablesaw when I had cast top versions of those was pretty common. I waxed them from time to time and when there was surprise rust, I sanded it off with 400 grit to a reasonable extent, oiled the top of the cast and wiped it off. A cover for table tops would probably stop it, but that seemed like a lot of trouble to me. Of course, it's not that much trouble, but seeming to be is enough.

 

[eribaMotters]

We have been experiencing excessive condensation up until a day ago when it warmed up. New build, very airtight and warm. I finally managed to get a dehumidifier, a 25L Maeco Arete, and what a revelation. Whilst still -8 to -10 at night outside we went from wiping down windows every hour to a light wipe in the morning and once more before going to bed. It was pulling 6L of water a day out of the air. Warmer weather is now here and it will now be used for drying clothes. Two maidens of wet cotton goods, grandsons nappies, and towels dried in 4 hrs with no heating on.
Back to the garage, I've done a similar thing with 400 grit and a thin oil, wiped clean and given a light wax. I do not seem to have a condensation problem on the cast iron, but must admit if I did I'd be after a dehumidifier for the garage.

Colin

​

 

[D_W]

drying clothes in humid weather with a dehumidifier is a great idea. it makes a little bit of heat and removes the moisture - the two things needed.

I used to use one here in the basement, but only the shop gets that damp and the air flow is a little too high (it's a garage and the door lacks tightness for that). The humidifier warms things up a little bit but turn it off and the benefit is gone on hours unless the objective is to use the water from it to water plants.

in the summer here, the central AC tube runs into the laundry sink drain. On a humid day cooling 1500SF and another 800 partially, it will reliably provide 5 gallons a day to water plants without going to the effort of filling a bucket otherwise. Without running it, nothing in the entire house can be put through a paper shredder.

 

[eribaMotters]

I've just double checked the garage and although no condensation on cast iron, I did see one thing. I have cheap mahogany type plywood for my radial arm bench top and a piece screwed to the thick aluminium pillar drill table. They are both damp. I've rummaged around through my sheet material and in all nocks and crannies and it is the only sign of any moisture I can find.

Colin

 

[Rhossydd]

I've never seen condensation like it here in my unheated garage workshop. 15 degree temperature rise in less than 12hrs.
Not just the big bits of cast iron suffering either, there's even droplets running down plastic finish bottles.

 

[Bingy man]

Working in an old house unoccupied for a few years .the last few days it’s felt warmer outside- -3/4 deg . Today all the surfaces are soaking wet and the condensation is trickling down the walls and architraves and doors . Having been inside the house for most of the day went outside for some much needed fresh air and it was like a summer day in terms of how warm was ( felt ) crazy crazy times.

 

[D_W]

from some research on the internets - it looks like dewpoint 75F air contains about 1 ounce of water per cubic meter. which along with the "bucket a day" comment above sort of illustrates how airtight the house isn't.

but 70-75F dewpoint stretches here are pretty common. to get a cold snap that occurs without dropping the dew point does not, though.

 

[Sideways]

Hopefully we all dodged the bullet.
The dehumidifier saved my butt and damage is limited to a little light flash rust on unprotected metal. Nothing that an oily rag or bit of scotchbrite can't fix.

Today is less traumatic. RH is starting at 86%

That gizmo was money well spent for me
Yesterday's run collected about 2.5 litres