I would have thought the relative humidity in Sweden was quite high for much of the year, especially around this time of the year. So its surprising that they expect their workbenches to be only used in warmer climes.
Sjobergs Bench
- Thread starter jwDave
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Trextr7monkey
Established Member
I have a second hand Sjobergs bench like the item described by original poster picked up second hand locally and a 1970s Emir school bench that cost £30.
The design of the Sjobergs drawers is rather basic and mine were a bit tight when purchased as bench bench had been in a shed. They have eased as it has slowly dried out. I fitted drawers under the emir using kitchen drawer runners with ball bearings and they are much more reliable and the way to go
The design of the Sjobergs drawers is rather basic and mine were a bit tight when purchased as bench bench had been in a shed. They have eased as it has slowly dried out. I fitted drawers under the emir using kitchen drawer runners with ball bearings and they are much more reliable and the way to go
Jacob
New Luddism. Wake up and resist.
Nothing to do with climate - indoor relative humidity is generally much lower than outdoor, unless you are looking at uninsulated unheated sheds, which is what I guess our OP has.
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@Jacob Think you got that the wrong way around for the UK, cooking and people breathing, showering and taking baths inside the home increases humidity, unless the house has forced ventilation inside will always be more humid than outside, and increasing the insulation and heating just make the humidity worse.
Jacob
New Luddism. Wake up and resist.
Only in the kitchen and the bathrooms. The overall indoor RH is lower simply because the temperature is higher, assuming a slow to normal rate of air exchange.
Jacob
New Luddism. Wake up and resist.
Temperature higher = higher potential water content = lower relative humidity.
There's a difference between absolute and relative humidity.
I think you overlook that continental climates tend to have long cold winters when any precipitation tends to fall as snow and does not evaporate leading to low humidity.
Jim
I bought a German made thermometer for indoors - it has a humidity reading too and works well - except it has a warning light which can only be set to 55% 60% or 65% even set at 65% the light is hardly ever out where I live in the UK, when I lived in Austria it was hardly ever on. The instructions said you need an indoor humidity of below 55% to stop mould - which is probably why I got a fungal infection in my ears last year!
Jacob
New Luddism. Wake up and resist.
Which leads to even lower relative humidity indoors.
Beside the point anyway, as our OP lives in warm wet Wales!
From the WWW:
Air at 25°C, for example, with a relative humidity of 100 per cent, would have an absolute humidity of 23g/m3. From there, it follows that if the relative humidity of air at 25°C were to drop to 50 per cent, absolute humidity would be 11.5g/m3 – or half as much. If the air were cooled to 14°C, its maximum moisture-holding capacity would decrease. The absolute humidity of 11.5g/m3 would then equate to 100 per cent relative humidity, and the air would be saturated. 100 per cent relative humidity in cold air represents a significantly lower absolute humidity than, for example, 25 per cent relative humidity in warm air.
Air at 25°C, for example, with a relative humidity of 100 per cent, would have an absolute humidity of 23g/m3. From there, it follows that if the relative humidity of air at 25°C were to drop to 50 per cent, absolute humidity would be 11.5g/m3 – or half as much. If the air were cooled to 14°C, its maximum moisture-holding capacity would decrease. The absolute humidity of 11.5g/m3 would then equate to 100 per cent relative humidity, and the air would be saturated. 100 per cent relative humidity in cold air represents a significantly lower absolute humidity than, for example, 25 per cent relative humidity in warm air.
Wee Willie Winkie ?
Actually the workshop is insulated but is I unheated as it is large (15m x 7m x4m high), heating it would cost a fortune!
jwDave, Relative Humidity (RH) is a factor of temperature and atmospheric pressure. As an approximation (and from memory), ignoring pressure which has a very minor influence, you reduce the RH by 10% by increasing the temperature by 2.2 Deg. Cel. Therefore you only need to maintain the outbuilding 7 degrees above the ambient to drop the RH to around 50% to 60% during winter. The main problem will be during summer when the RH is still high and you will have the doors open etc.
Living in a very drafty timber-framed house built in the late 1500's has taught me a lot about RH and its effect. After the summer is when you will notice the most absorption of moisture. Firewood always burns better in January and February because it is generally colder and the actual volume of moister in the atmosphere is lower thereby lowering the water content of the firewood on the outside if it is in a high airflow environment and kept dry.
Living in a very drafty timber-framed house built in the late 1500's has taught me a lot about RH and its effect. After the summer is when you will notice the most absorption of moisture. Firewood always burns better in January and February because it is generally colder and the actual volume of moister in the atmosphere is lower thereby lowering the water content of the firewood on the outside if it is in a high airflow environment and kept dry.
Thank you for the insight, this thread has taught me a lot more than I bargained for!
Jacob
New Luddism. Wake up and resist.
If it has windows then solar gain can make a big difference as long as the shed is also reasonably draught proof.
But unless you want to alter the building, or heat it, the obvious solution is to deal with the bench and free up the bits which are sticking.
Shouldn't take long!
Wood acclimatises to it’s environment.
As a woodworker, one or two strokes with a plane would probably cure your problems for ever.
As a woodworker, one or two strokes with a plane would probably cure your problems for ever.
The problem is that the wooden ‘slider’ in the shoulder vice cannot be removed to ‘plane‘ it.
jwDave, When you eventually recover the workbench to its working moisture level it might be an idea to apply a coating of oil (if not already coated) in the areas most affected. This will slow down the moisture takeup but it won't stop it. You could also add a small heater (perhaps 15 or 25 watts) inside/underneath.
