MikeKopman
New member
Has any body heard about the chemicals in moisture absorbing crystals having a detrimental ie corrosive effect on electrical wiring?
Mike
Mike
Moisture absorbers
- Thread starter MikeKopman
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ccscott49
Active member
Haven't heard of it and they do put slica gel packages in boxes of eletrical equipmentand even open containers of the stuff.
MikeKopman
New member
Yes of course! I hadn't even thought of that! Most sensitive electrical equipment comes packed with silica gel... I guess that answers that question! Thanks.
Rob_Webb
Active member
Well I don't think that they are quite the same thing, are they? The packs of silica gel prevent physical contact with anything because of their paper sac - but I seem to remember the last time I used a moisture trap that the instructions warned that the treacly solution created when the chippings have absorbed water can be quite nasty and require careful disposal - so maybe the resulting solution is a bit corrosive? Sorry I can't remember specifics, it's just a vague recollection.
MikeKopman
New member
Actually the reason for my original post was that I hgad heard that just the proximity ie no physical contact necessary, of the moisture absorber was detrimental to wiring. This obv cant be the case, as the inclusion of silica gel with electronics proves.
Rob_Webb
Active member
Well, the reason I'm not so sure is because I think you are dealing with very different chemicals.
The silica gel packs absorb a very limited amount of water and certainly don't become saturated to the extent that they become heavy/wet/liquid etc. What small amount they do absorb can be reversed by gently drying them.
But the crystals that you put into those plastic water traps are not simple innocuous silica (but the trouble is I can't remember exactly what they are!) - and they are designed to absorb much larger quantities of water and to dissolve themselves into the resulting liquid sludge - this process is basically non-reversible from a user point of view.
Given that I recall that the resulting liquid can be harmful (slightly acidic/corrosive?) then it is possible that it gives off some vapour that could be corrosive to sensitive wiring.
I realise I am not being very conclusive but that is where I think the original concern might have come from?
Rob
The silica gel packs absorb a very limited amount of water and certainly don't become saturated to the extent that they become heavy/wet/liquid etc. What small amount they do absorb can be reversed by gently drying them.
But the crystals that you put into those plastic water traps are not simple innocuous silica (but the trouble is I can't remember exactly what they are!) - and they are designed to absorb much larger quantities of water and to dissolve themselves into the resulting liquid sludge - this process is basically non-reversible from a user point of view.
Given that I recall that the resulting liquid can be harmful (slightly acidic/corrosive?) then it is possible that it gives off some vapour that could be corrosive to sensitive wiring.
I realise I am not being very conclusive but that is where I think the original concern might have come from?
Rob
MikeKopman
New member
Hmmm, interesting, I see what you're saying.
In the orginal question, which I am endeavouring to answer, the reader described 'bags with crystals' which sound like silica gel to me. What are the water traps you are referring to?
In the orginal question, which I am endeavouring to answer, the reader described 'bags with crystals' which sound like silica gel to me. What are the water traps you are referring to?
Rob_Webb
Active member
They are basically plastic rectangular containers about 8" long x 3" wide by 4 " tall. They have a solid base and a perforrated lid and a mesh layer between them. You pile these crystal onto the mesh layer and sit this onto the base and then pop the perforated lid on top. Moisture enters the perforated lid and is attracted to the crystals which then disolve into a liquid and fall through the mesh they are sitting on and collect as a liquid sludge in the solid base. Typically on my boat during the winter or sailing at the extreme endds of the season when the air is damper, all the crystals have been dissolved in about a week and you get about a pint of liquid in the bottom trap. Then you start again. There is a danger that as these things fill up the liquid could spill out and whilst it's not exactly battery acid, I don't think it's very nice. And it does have a slightly acrid smell which could be the corrosive aspect mentioned?
MikeKopman
New member
Yes, that sounds most likely. I cannot see any harm in using bags of silica gel crystals, apart from the danger of someone mistaking them for sugar or rock salt! Incidentally, what are the costs of keeping these trays, stocked with crystals, in your boat for the winter? Just wondering about the financial feasability of using a dehumidifier, or even a knackered old 'window shaker' a/c unit, to remove moisture. We used to use one on a race boat, after every race... it was brilliant, but pricey.
ccscott49
Active member
I've just read the posts about the household dehumidifiers, I've had some of those, I doubt the fumes are acidic or corrosive, as they are designed to be put in your wardrobe to keep your clothes from becoming damp, corrosive liquids fumes etc, in a wardrobe might be a little dodgy on the clothes and on law suits when they fall over or eat there away through the wardrobe! I didn't see any warnings of spillage or fumes etc. but of course I could have missed them, however something desined for household use, I doubt is as dangerous as is being considered. IMHO of course.
Trevethan
New member
Try tossing in a bag of (new) pampers nappies.
A friend of mind left one in his boat over winter and it expanded hugely. It must have weighed a good kilo or two. After then he littered his boat with them over winter and swears that they keep down the moisture. cheaper than silica gel too!
A friend of mind left one in his boat over winter and it expanded hugely. It must have weighed a good kilo or two. After then he littered his boat with them over winter and swears that they keep down the moisture. cheaper than silica gel too!
BrendanS
Well-known member
The stuff you're talking about is calcium chloride. When it gets wet it becomes caustic and quite corrosive (will eat through stainless steel). Would definitely recommend that the liquid is kept away from wiring! Not sure about fumes from it though?... would have to go back through some old chemistry books.
If anyone is going to use it in boats, like anyother absorbent material it works best in confined spaces, and is cheapest when bought as refill packs in plastic tubs of 2.5kg or more. If you can find a retail chemical supplier you could buy an entire winters worth for peanuts
If anyone is going to use it in boats, like anyother absorbent material it works best in confined spaces, and is cheapest when bought as refill packs in plastic tubs of 2.5kg or more. If you can find a retail chemical supplier you could buy an entire winters worth for peanuts
ccscott49
Active member
we use lilterally tons of the stuff in the oilfield in drilling muds, but as for its corrosive properties, I just checked with the mudman, no more corrosive than sea water, which given time will also eat through stainless steel. (depending on quality)
BrendanS
Well-known member
Without wishing to get involved in chemistry arguments( I hated it at school) sea water is a very dilute solution of sodium chloride. If you make it more concentrated it will eat through stainless steel more quickly. Sea water will have the same effect as the concentrated stuff eventually, just takes a lot longer. Calcium chloride is exactly the same. The stuff in the bottom of the trap after it has absorbed water is very concentrated, and hence far more corrosive than sea water. I was making the point that concentrated calcium chloride is destructive to stainless steel, so is not going to be beneficial to any sort of electrical wiring which is a lot more susceptible to chemical damage, which was the point of the original question
dickh
New member
The liquid from these domestic moisture absorbers kills grass!! As I found out after throwing out this 'liquid' in the bottom of the tray - well, I didn't know it was a moisture absorber did I?! - took about 2 weeks for this strange mark to appear on the grass, and ages to figure out what had caused it.
dickh
I'd rather be sailing...
dickh
I'd rather be sailing...
ccscott49
Active member
A whole two weeks! wow! Catpiss will cause that, much faster! But I see your point!
ccscott49
Active member
Brendan?
The opoint I was trying to make without upseting anybody, ids that the fluid is not a lot more corrosive than sea water. Thats all, originally I thought he was talking about silica gel, not calcium chloride. But if he wants to de-humidify a boat, which is what it would have been better to ask I would have said "you will need about 1/2 ton of the stuff to do any good in a british winter, so go for electrical means" I retire from this discussion! Wouldn't want to upset anybody not very PC.
The opoint I was trying to make without upseting anybody, ids that the fluid is not a lot more corrosive than sea water. Thats all, originally I thought he was talking about silica gel, not calcium chloride. But if he wants to de-humidify a boat, which is what it would have been better to ask I would have said "you will need about 1/2 ton of the stuff to do any good in a british winter, so go for electrical means" I retire from this discussion! Wouldn't want to upset anybody not very PC.
