Damp Rid Dessicant

Uhhttps://www.practical-sailor.com/belowdecks-amenities/high-and-dry-for-winter-storage

Above is a link about dessicant.

I just purchased a Grand Banks 36. This week I moved it up the bay in moderately rough weather. Lots of short duration quartering waves on the beam and stern..lots of rock, roll, and yaw.

Previous owners had placed 4 small containers of Damp Rid in plastic tubs..one in the flybridge locker. and three in the heads. I was not familiar with product..the tubs looked fairly new, so I gave them no thoughts.

Unknown to me, tubs had absorbed enough moisture that the tubs were just a liquid. And, the rough weather had upset the one in the flybridge locker.

We noticed two large wet spots on the teak deck next to the locker and liquid below on the dinghy cover and starboard grab handle. The liquid spots were not drying out and when I touched the grab handle, my hand was burned like I had put it in battery acid.

We quickly figured out the wet spots were from the Damp Rid spillage into the locker..and draining out thru drain holes in the locker...we flushed everything with water and then soap and water.

We then proceeded to rid the boat of Damp Rid and disposed all four tubs.

The linked article informs about this stuff. It absorbs moisture, but it turns to a dangerous corrosive liquid...and if tipped over can cause damage. Not recommended for boats and if used, the tubs should be removed within 60 days or before the crystal's turn to corrosive liquid.

Wish I had known...so I am sharing so someone else will not have the same headache. Pretty sure many have used the product without a problem..especially if they only you leave on board for a short time
but carrying an open container of hazardous corrosive liquid in a boat underway does seem dangerous.

Not sure what damage to the teak deck..so far, there are dark stains..hopefully I can restore teak so the dark spots go away. I am lucky that I had nothing stored in the locker.

I use it over the winters, but I also tend to put them in buckets, etc so a leak is contained if it happens. I never have them on the boat during the season when a spill is likely though.

Sorry to hear about your misfortune.


I simply will not use the stuff on my boat for the reasons you explained.


The few times I have used it the containers are always put into a bucket or H.D.dishpan.

Calcium Chloride is a very effective dessicant, but the byproduct of the process is dangerous.

I know that now..

Wish I had known sooner.

I have used silica gel in my gun safe for years without troubles. And just heat it up to regenerate. Putting it in our oven does annoy the wife tho.

Congrats on your new baby. Sorry to hear about the mess. Thanks for the heads up.

I've got a tub of this stuff in a couple of my hanging lockers right now. I had no idea. THANK YOU for posting that!

Had no idea. Many thanks.
Now will be banned from the boat.

I had a similar experience when I first moved into my house. I found a tub of liquid Damp Rid in a closet. As I was taking it out some spilled on the wooden floor. No problem, I just wiped it up. A few hours later the spot was wet again. This went on for several days with out any change. I finally cut that section of floor out and replaced it.

That's exactly why we have about 15 of these strategically placed all over our boat: https://www.pacificnwboatertested.com/products/h2out-space-dryers

https://sciencing.com/mix-calcium-chloride-water-7447614.html

Above link is article about dissolved calcium chloride which produces hydrochloric acid. So I guess if you do store it in buckets, or use buckets to protect against spills, they should be plastic buckets. Not metal ones.

Searching for ways to remove spills/stains from wood.

I used to use Damp Rid but stopped for the reasons mentioned, as advised by the boatyard I use. I now use a compressor-type dehumidifier. Another thing to avoid is dumping the Damp Rid discharge water down a sink and into your boat's plumbing, based on its corrosiveness.

https://ask.metafilter.com/326113/Cleaning-up-spilled-Damp-Rid-liquid-on-tile

Link above to discussion about removing "oily residue" stains on wood from Damp Rid....lots of hot water..lots.

I agree that "mechanical dehumidification" is probably best solution for boat. If boat is in water with a reverse cycle heating, a poor man's method is to turn heat on, followed by AC..basically doing what a dehumidifier does.

Greetings,
Mr. s. IF in fact the end product of this Damp-rid stuff is HCl, sprinkle some baking soda on the stain and dampen it. This should neutralize any residual acid and may help the stain,.

Even the little Peltier Effect dehumidifiers are more effective than a Damp Rid. I used one to drop the humidity in Possums’ cabin from 80% down to close to 60%. Completely eliminated my mildew problem.

HopCar said:

Even the little Peltier Effect dehumidifiers are more effective than a Damp Rid. I used one to drop the humidity in Possums’ cabin from 80% down to close to 60%. Completely eliminated my mildew problem.

Click to expand...

I used a short piece of aquarium airline and a drill bit to make an automatic drain into the sink for my little dehumidifier. Now, it accumulates a cup of water and then builds enough hydrostatic pressure to drain out the hose and self-empty the tank into the sink. It empties itself every day or so, depending on the humidity, and keeps the RH down to about 55-60%

Back on the farm (in my early years), we used calcium chloride to fill tractor tires for additional weight and traction. Adding it to the tires was a day long process, and a pump would last about three tractors before we had to rebuild the pump or replace it. Not something I would want to mess with now, for sure.

stubones99 said:

I used a short piece of aquarium airline and a drill bit to make an automatic drain into the sink for my little dehumidifier. Now, it accumulates a cup of water and then builds enough hydrostatic pressure to drain out the hose and self-empty the tank into the sink. It empties itself every day or so, depending on the humidity, and keeps the RH down to about 55-60%

Click to expand...

That’s exactly what I did. Worked great.

After soaking with Dawn dishwashing liquid, then rinsing...and later applied baking soda on stained area, wetted and rubbed in, let set, then rinsed with lots of water. Stain is significantly reduced and teak no longer showing that oily residue, but teak still slightly darkened...not the weathered grey in those spots. Teak is probably not damaged, but the spots have been "treated" changing color back to more normal brownish tint.

HopCar said:

Even the little Peltier Effect dehumidifiers are more effective than a Damp Rid. I used one to drop the humidity in Possums’ cabin from 80% down to close to 60%. Completely eliminated my mildew problem.

Click to expand...

Is there one you would recommend? Are any 12 volt? I gotta get that stuff off my boat.

Thanks.
BD

Parks...reviews on the internet say those units dont work well in very hot cabins....any advice....?

....I never have tried or used damp rid for several reasons.

BDofMSP said:

Is there one you would recommend? Are any 12 volt? I gotta get that stuff off my boat.

Thanks.
BD

Click to expand...

I don’t know the actual voltage they run on. They come with a transformer in the power cord that drops the voltage. Probably converts it from ac to dc as well.

HopCar said:

I don’t know the actual voltage they run on. They come with a transformer in the power cord that drops the voltage. Probably converts it from ac to dc as well.

Click to expand...

I'm probably overthinking it - I really need it most when I'm away from the boat for awhile, and then I'll be on 120. Any recommendations from the Forum are welcome.

Thanks
BD

psneeld said:

Parks...reviews on the internet say those units dont work well in very hot cabins....any advice....?

....I never have tried or used damp rid for several reasons.

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My boat lived in the South Florida sun. The cabin was closed up. The little dehumidifier, about the size of a loaf of bread, dropped the humidity between 15 and 20%.

The cabin was pretty small. Just room for a V-berth and a small galley and head. The unit ran 24/7 and the cabin wasn’t opened often.

I did have a hygrometer in the cabin so I could check the humidity. The target to prevent mildew is about 60% or lower. It didn’t quite get down to 60% but close enough.

If you have any sort of volume in your cabin or you ever open the hatch the Peltier system will be insufficient.

Woodland Hills said:

If you have any sort of volume in your cabin or you ever open the hatch the Peltier system will be insufficient.

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True, but it’s a lot better than a tub of Damp Rid. They’re meant to use in small spaces like closets or other small rooms. If you go in and out of the cabin frequently, it won’t be able to keep up. It took about two days for mine to drop the humidity after I used the boat. Given more time it would drop the humidity in a larger area. At some point it’s just more practical to turn on the air conditioner or spring for a compressor style dehumidifier.

The Peltier machine worked for me because poor Possum was a pretty small dock queen.

In my mind, damp rid is for a boat stored over the winter where power isn't available constantly. For anything else, there are better options.

Anyone familiar with the desicant dehumidifiers like this one. They work over a wider temp range than compressor types.

https://www.amazon.com/dp/B07B8SCPZ4/ref=cm_sw_r_other_apa_i_NkiZEbY0JVWAK

I've had good luck as well with the small Peltier dehumidifiers as well. I have two of them on our Mainship 400, one in the galley sink and one in the head sink. I prop both head doors open to promote better air circulation. Not perfect, but I don't have much of a mildew problem, even sitting in the South Florida sun. I'm considering buying a third, they aren't expensive.

HopCar said:

Even the little Peltier Effect dehumidifiers are more effective than a Damp Rid. I used one to drop the humidity in Possums’ cabin from 80% down to close to 60%. Completely eliminated my mildew problem.

Click to expand...

BDofMSP said:

I'm probably overthinking it - I really need it most when I'm away from the boat for awhile, and then I'll be on 120. Any recommendations from the Forum are welcome.

Thanks
BD

Click to expand...

Hopcar, you're the one who introduced me to the Peltier Effect devices. I bought an Eva-Dry on your recommendation and it has never failed me. I just drilled and suspend a 1/4" hose into my sink when needed while away from the boat in the slip in winter. If I'm running low on distilled water for the batteries, I'll fill a gallon jug in the sink.

Moonfish said:

That's exactly why we have about 15 of these strategically placed all over our boat: https://www.pacificnwboatertested.com/products/h2out-space-dryers

Click to expand...

Those look great, Daren. Great info on the propane stove refreshing req'ts. I especially like the engine-top reset. I've heard of guys who heat food that way...

Do you think they'd refresh fine in a countertop electric skillet with proper lid venting. Seems like a great product for the cruiser.

FlyWright, I never thought to gather the drain water, nice.

Dehumidifiers

I have found while the boat is in storage the best is big containers of bbq briquettes. Never any mould or moisture problems. You just leave them in the sun to dry out then put the lids on and reuse the following year.