Dehumidifier crystals

[Ex- Member]

Spotted these today in Aldi and thought we would give them a go as we've noticed our duvets can be quite dank sometimes. We also store lots of clothes under the bed in baskets and we want to avoide those getting dank as well.

 

We tend not to have the heating on much as it just gets so hot, it's not that cold here at the moment between 13 and 18c over the past week. Not really cold enough to run the bubble stove.

 

I've heard these crystals mentioned on here before. Aldi are doing a 4 kilo pack for £6.99 and a starter pack for £7,99 with container and 3 x 1 kilo bags of crystal.

[mango]

There is a lot of moisture in the atmosphere, so the desiccant properties of crystals will not last long. The bags of silica gel included in new electrical goods only help because they are in a sealed box.

 

I suggest you buy self-indicating silica gel, which is blue, but changes to pink when exhausted. Use it in a cloth container such as a sock and put it in with the clothes in a plastic bag without holes. It can be regenerated by heating in an oven or microwave.

 

Some desiccants don't change colour, so you will not know if they are still active and others turn into a liquid when they absorb moisture, which is not very convenient.

[Dyertribe]

Would those vacuum bags do the job for you? My aunt uses them in her holiday caravan ans swears by them.

[ditchcrawler]

We have tried these bags and so far have had problems finding reliable sealing bags.

[geoffwales]

I believe once saturated you can dry them in the oven

[tree]

Would those vacuum bags do the job for you? My aunt uses them in her holiday caravan ans swears by them.

second that,.... as the only things that didnt get spoiled/wet on my boat before was the clothes that I had stored in vacumm bags.

 

i didnt even get expensive ones, I got mine from 'Wilko's for a couple of quid. In the caravan I leave my wardrobe open a bit as well as the drawers underneath.

 

What I will do on my re-fit is make sure that my wardrobe has holes drilled at the top and bottom and as well as laying my mattress on wooden slats, the midi

 

wardrobe that will be underneath my raised bed will also have holes nicely drilled along the bottom for ventilation. Hope this idea helps

Edited November 5, 2013 by tree

[Beaker]

I believe once saturated you can dry them in the oven

Whereupon all the moisture goes back into the air in the boat. <rolls eyes> (lost my smileys).

[geoffwales]

You could put them in the oven at home or when you are on the boat with doors open so the moisture content evaporates out to the ambient.

[Ex- Member]

Would those vacuum bags do the job for you? My aunt uses them in her holiday caravan ans swears by them.

 

To be honest there's not really that much of a problem, we ran the stove yesterday evening for the first time through the night. Very hot but everything is now bone dry including the crystals

 

We've put 2 x 1 kilo bags in the bedroom anyway even though all is dry. We really should put the heating on more often but we really don't feel the need whilst the temp is 12c or above. We were cooking in here this morning with the boat up to 22c

 

Temp in the boat at the moment is 15.5 and I'm just wearing shorts

 

ETA, no heating on.

Edited November 6, 2013 by Julynian

[trackman]

Drying them in the oven of a solid fuel stove is the ideal. The dry heat of the stove dissipates the moisture that's driven off.

Drying them in a gas oven is a double whammy, not only do you get the water vapour off the crystals, you also get a load from burning the LPG, all adding to the moisture in the air in the boat. Not ideal.

[geoffwales]

Approximately .9litre of moisture is produced when burning 1kg of fossil based fuels i.e. gas, coal, wood

[Ex- Member]

I reckon the best way to dry them is on the engine block when running the engine or cruising. Plenty of heat and moisture will dissipate easily and quickly with all the ventilation available in there.

 

We do have a nice flat engine top though, but we could even hang them from the stern decking rails.

 

No heating on yesterday or last night and bedding is fine, the Crystals though do seem to have some slight moisture in them, they really do seem to work.

[mango]

If you have silica gel, putting it in the oven at a low heat will regenerate it. A microwave will do the job efficiently, but don't use full power or you may turn the crystals to a powder. The engine is not likely to be hot enough to do the job.

 

If you have calcium chloride or calcium sulphate, it will absorb sufficient moisture to become a solution. Drying this will produce a hard lump, so this desiccant is really single-use. Calcium chloride is also corrosive to steel – much like salt is. If your crystals are beginning to look damp, my guess is that you have a calcium salt.

[Beaker]

You could put them in the oven at home or when you are on the boat with doors open so the moisture content evaporates out to the ambient.

 

Well, slap my thigh! I'd never have thought of that!

[Ex- Member]

If you have silica gel, putting it in the oven at a low heat will regenerate it. A microwave will do the job efficiently, but don't use full power or you may turn the crystals to a powder. The engine is not likely to be hot enough to do the job.

 

If you have calcium chloride or calcium sulphate, it will absorb sufficient moisture to become a solution. Drying this will produce a hard lump, so this desiccant is really single-use. Calcium chloride is also corrosive to steel – much like salt is. If your crystals are beginning to look damp, my guess is that you have a calcium salt.

 

I don't see why?

[mango]

 

I don't see why?

I doubt you would achieve much more than 80C on top of a water-cooled engine. In a thermostatically-controlled oven at this temperature, it takes quite a long time to regenerate silica gel, compared with 110C for example. I have regenerated lots of silica gel at work.

[Ex- Member]

I doubt you would achieve much more than 80C on top of a water-cooled engine. In a thermostatically-controlled oven at this temperature, it takes quite a long time to regenerate silica gel, compared with 110C for example. I have regenerated lots of silica gel at work.

 

We have crystals, the engine would certainly dry those out as they seem to have dried out at room temperature anyway, currently too hot at 21c

[ditchcrawler]

I doubt you would achieve much more than 80C on top of a water-cooled engine. In a thermostatically-controlled oven at this temperature, it takes quite a long time to regenerate silica gel, compared with 110C for example. I have regenerated lots of silica gel at work.

This site http://www.geejaychemicals.co.uk/faq.htm says 100 deg C

[mango]

This site http://www.geejaychemicals.co.uk/faq.htm says 100 deg C

That seems reasonable because water boils at 100C. I have only compared 80C and 110C because that's what the ovens were set at.

[blackrose]

I don't really understand why everyone's sufferening from all this dampness? I came back from a weeks holiday a couple of weeks ago. It was certainly cold onboard, but no dampness. I never find damp clothes on my boat. I even hang damp clothes from my washing machine in the bathroom and saloon but there's no dampness anywhere else. Why does one boat suffer from dampness and another doesn't?

Edited November 6, 2013 by blackrose

[mango]

I don't really understand why everyone's sufferening from all this dampness? I came back from a weeks holiday a couple of weeks ago. It was certainly cold onboard, but no dampness. I never find damp clothes on my boat. I even hang damp clothes from my washing machine in the bathroom and saloon but there's no dampness anywhere else. Why does one boat suffer from dampness and another doesn't?

People, showers, ovens, hobs and cooking put moisture into the a boat. Flued appliances (but not balanced-flue) and ventilation help to remove it. There are huge differences, depending on how boats are used.

[tillergirl]

Another vote for vacbags............we live on board and i use them for storing bedding and out of season clothes under the bed. We also have a couple of damp traps under there to collect any moisture from the mattress. Been on board a year now and they work well for us. Not lost a single item to damp.

[blackrose]

People, showers, ovens, hobs and cooking put moisture into the a boat. Flued appliances (but not balanced-flue) and ventilation help to remove it. There are huge differences, depending on how boats are used.

 

But any humidity gradient between the inside of a boat and the outside environment would eventually even itself out surely? Don't you lot have non-closeable vents on your boats? How a boat is used shouldn't really matter that much unless you've got a sauna in there! I live on mine and cook everyday, wash up with hot water from a non-balanced flue gas water heater, shower everyday from the same water heater, hang up a load of damp clothes to dry at least once a week... yet my boat suffers no dampness.

Edited November 6, 2013 by blackrose

[mango]

 

But any humidity gradient between the inside of a boat and the outside environment would eventually even itself out surely? Don't you lot have non-closeable vents on your boats? How a boat is used shouldn't really matter that much unless you've got a sauna in there! I live on mine and cook everyday, wash up with hot water from a non-balanced flue gas water heater, shower everyday from the same water heater, hang up a load of damp clothes to dry at least once a week... yet my boat suffers no dampness.

It depends how many people you have on a boat too. Assuming that your water heater does have a flue, that will help remove moist air and so will a solid fuel stove.

[mango]

Desiccants could be useful if you drop your phone or camera in the water. The usual recommendation is to use rice, but desiccant will be far more effective. Put the phone etc. in a sealed container (e.g. plastic box) with desiccant. If the desiccant is silica gel they can be in contact but other desiccants should be kept out of contact with the phone.

 

The drying process is very slow unless you have a vacuum pump to remove the air.