De-Icers

[egatlake]

Does anyone have any info on what type of de-icer to use.

[SIKSUKR]

A de-icer for what?

[BroadHopper]

What are you de-icing?????

[jimbob1603]

I use a bubbler; made from 3/4" PVC pipe (1 hole drilled every two feet) and a linear air compressor. Other types of air compressors are too expensive to run.

Many people use a circulator (water tight motor with a propeller on the end), but, these too, are expensive to run.

Either one can be attached to a thermostat so that it only runs when the temperature dips below 35 deg.

The smartest people have a crank-up dock; costs nothing to run; no problem with extended power failures.
J

[Bear Islander]

I use a 3/4 horsepower "Ice Eater" with a thermostat. It will keep a 30' diameter clear under normal winter conditions. They have other models from 0.05 HP to 1 Hp.

[islandAl]

I have mine on a 24 hour heavy duty timer set to turn on for 2 hours 3 times a day. keeps the piers clear and is cheaper to run than fixing the ice damage.

[ACutAbove]

From my experience 3/4 horsepower is the way to go. The Ice eaters when you buy them usually there is an attachment for a thermostat that you can but to use with it. There are also companys in the area that will monitor for you during the winter if you are not here to keep an eye on it.
Just so you know if a piece of ice or something gets lodged in one and the propeller breaks or the motor dies, you will end up with the exact problem you are trying to prevent.

[camp guy]

Most any de-icer will do the job of keeping the area around a pier clear; but the real problem with piers and ice is during "ice-out". At this time the ice breaks up and forms zillions of small icebergs. When the wind blows away from your dock, and floats these away - all is fine, but, then, if the wind shifts and blows these back this is when damage can occur. It doesn't take much to cause damage when you have a large iceberg being pushed by a fresh breeze. Somebody fluent in the laws of physics can explain mass - energy - and momentum with respect to dock damage.

[Merrymeeting]

Shouldn't there be some type of rule against asking questions like this until at least Halloween?!!!! :laugh:

[Mink Islander]

I have a 1/2 HP and a 3/4 HP Ice-Eaters. Quite expensive investments, though very long-lived. Both work fine. Use separate timers and offset the run times. Been thinking of switching one over to a temperature-actuated sensor instead to save $$. Depending on how frequently you cycle the ice-eater, your electric bill can easily be hundreds of dollars for the season. You need to be able to inspect them occasionally or have one of the services do it during the winter.

Don't forget to buy/install "thin ice" signs too.

[Bear Islander]

Don't forget to buy/install "thin ice" signs too.

Good Point!

And the "thin ice" sign must be the unusual New Hampshire version. Some of the local hardware stores have them including Heaths in Center Harbor.

[islandAl]

Most any de-icer will do the job of keeping the area around a pier clear; but the real problem with piers and ice is during "ice-out".

I always thought that as well untill I did some straightning and reinforcing of the crib and when I went up that winter, it was already danaged. The next season I had the circulator going and no problems since. The electric bill is still less than the repair costs both in material and time.
Not to say that a bay full of ice, many multiple tons, do not cause lots of damage in the spring. There is also the rise and fall of the ice that lifts or dives posts deeper.

Is the linear compressor style less expensie to run than the circulator. Seems it would be a little more work to put in and take out each season.???

[jimbob1603]

Ho,
A linear compressor is dirt-cheap to run. I have a big one (7cfm@6psi), and it only sucks about 100 watts; costing me about $50 to run for the entire season. However, it cost $900 to purchase. So, you need to use it for a couple years to recoup the initial investment. Unlike a reciprocating compressor, a linear compressor is made to run 24/7 and has no bearings to wear out. Mine is on a thermostat, so its only running when temp drops below 35.

$900 might initially sound expensive. But, remember that circulators cost $300 to $500; and cost hundreds of dollars to run each season.

It does take more effort to initially install the bubbler pipe/hose, but its all part of the fun/challenge. I leave mine in all year, and just disconnect the compressor in the spring.

An unexpected side effect: the bubbles seem to attract fish.

I agree that ice-out is the most trecherous time. An ice floe can crush everything in its path; the scene can get quite ugly. Fortunately, I'm in a cove and don't have to worry about that danger.

J

[Misty Blue]

Jim Bob

Can you get me more information on the linear compressor. I will have to retire my home made circulator soon and with electricity selling for $123.50 wholesale (I work for the power company) I am ready for a more energy efficient system.

Also about the ice flows....I have saved a coupple of docks in my neighborhood (Braun Bay) lashing 1 1/2 steel pipes (the kind that are used for temporary docks) at an angle between the lake bottom and the deck of the dock. When the ice flow meets the pipes it rides up the pipe and breaks into smaller, less damaging pieces. My dock is rather shallow and a deeper dock may require poles that are too long to haldle.

'Works for me. Hope that this is a help.

[jimbob1603]

I purchased my compressor from LMI, http://www.lmimg.com/OrderPage.asp?PN=DB150L. LMI, I believe, also sells an appropriate thermostat. Gast is another company that offers linear compressors.

The compressor cost me about $850 3 years ago. Its absolutely designed to run 24/7; but with a thermostat, it runs only when it is needed. It is expensive to purchase, but dirt cheap to run. I stuck an amp-probe on, and it works out to about 100 watts ..... I'd like to see a 1/2 hp circulator run on 100 watts!! NOT :laugh:

I made my own diffuser using 3/4" PVC pipe with a 1/32" hole drilled every 2 feet. It takes some patience to install the pipe ..... it has to be level (about 2' below water surface) for proper air flow. I have installed diffuser pipe along both sides of my 32' dock, and employ 3/4" hose to connect it to the compressor (which is set up under a deck, to protect it from the weather). But, I feel that one diffuser pipe running underneath the middle of a 6' wide dock would be a sufficient alternative.

My setup works great to keep water from freezing/crushing my dock. But, be aware that no circulator or bubbler is going to prevent a wind-driven ice floe from 'having it's way' with your waterfront. I'm lucky enough to be in a cove and don't have to worry about wind-driven ice.

I don't recommend plugging the compressor into a GFCI. Those damn things trip if you look at it cross-eyed. And the last thing you need is an air compressor with no power to run it.

Have fun! J

[fatlazyless]

If the water is shallow, say six feet or less, than all you need is a 1/6hp utility pump which costs about $65. Getting the one with the big handle on top makes for easier positioning for two or three way tie-offs. The 1/6hp pump can last for 1-2 seasons before burning out. Plus, they make a lot less of a racket what with gurgling water than by using a 3/4hp circulator in shallow water. Here's for happy circulating and a great Autumn season.........kerplunk! That was an oak leaf falling on the Winni waters.....in case you was wondering.

[Misty Blue]

I just built a jimbob linear compressor-PVC pipe special under my dock. I chickened out on the 1/32 holes and went with 1/16 holes. This may have been a mistake. We will see.

To celebrate I went out and purchased a new (my old one was 20 years old) DANGER THIN ICE SIGN. Wow...The thing cost me 40 bucks at Heaths and as I checked out I was cautioned that it may need to be backed up or it will break in a wind! 40 bucks and I had to construct a frame to keep it from breaking just in case it gets cold and the wind blows on the Lake in February!!! That's just not right!

PS. I noticed that yellow road signs are about the same size as the thin ice signs. Any ideas?

Misty Blue.

[islandAl]

..... it has to be level (about 2' below water surface) for proper air flow. I have installed diffuser pipe along both sides of my 32' dock,

Thinking of this year where the lake will probably drop another foot or more after I leave, till solid ice, how do you set the deapth? Do you hang the pipes or mount on legs to the bottom? Probably will be replacing for next winter, the expensive circulator that is now getting old but has done the job. What if you have multiple piers, I have 3 that need protection and the one circulator keeps the ends open, and must be able to get in and out as I am on an island.
What would the effect on air flow be if there was only 1 foot of water, 3 feet?

[jimbob1603]

I have lashed my diffuser pipe to the pilings/legs of the dock. Whether its down 1 foot or 3 feet is not an issue (I keep mine at 2 feet). But, it is critical that the entire diffuser be kept level. If it isn't level, air will not come out of the 'low' holes. The air will seek the path of least resistance (usually the holes closest to the water surface)

As an alternative to lashing it to the structure (which requires you to get wet to adjust the height), it can be hung from the dock. I made weights ( 10' rebar inside 1/2" pvc pipe; capped to keep the water out) and tied them to the diffuser pipe. Without some sort of weight, the diffuser will just float to the surface. This method allows you to adjust the diffuser pipe from the dock so you can make it level.

You can hook up 3 seperate diffusers for 3 seperate piers and run them off of one linear compressor. But, all 3 'circuits' must be level to each other; or else the low one probably won't bubble.

Be sure to test the system at whatever depth you expect it to operate. Don't set it up for 2 feet and expect it to run properly at 5 feet. Linear air compressors have a low pressure/high volume output and don't play nice at over 8 psi.

It takes surprisingly little water movement to keep ice from forming. If your system looks like a run-away Jacuzzi, you've got way too much air. Don't sweat it if a little crust builds up .... its the big stuff you need to worry about ... especially in spring.

It takes some work to build it and test it; but just think of how much cash you'll be saving because of low electrical bills. I'll be going up and turning the compressors on sometime in early December; even then they are on a thermostat and will run only below 35 deg..

[Purple Hays]

I bought an LMI linear air compressor and am about ready to install my bubbler. For those of you that have done this, what kind of check valve did you install to prevent water from backing up in the air supply line, freezing and subsequently preventing air from flowing? This is only a concern for me when the power goes out but that is a common occurrence on my lake.
Thanks

[jimbob1603]

I don't have a check valve on my setup. My place is in Alton and have not had a problem with freezing lines caused by a power outage. But, I do understand the concern; especially if you are subject to prolonged outages.

I found that the linear compressor itself is tight enough to act as a check valve. When the power fails, water enters the bubbler line; but this is not a problem because the bubbler line is well below any potential ice. The air hose leading from the compressor is connected to the bubbler line at the same 'safe' level below the ice. The water will only rise to about the highest hole in the bubbler line. So, even if the power fails and allows 12" of ice to form around the dock, the compressor just starts up (when power returns), and bubbles start attacking the ice .... no problems.

You can prove this out in the warmth of your kitchen by placing a clear vinyl air hose from the compressor into a 5 gallon bucket full of water. Make sure the hose is straight & vertical, the open end is at the bottom of the bucket, and all connections are air tight. Momentarily turn on the compressor to clear the hose of water (stand back ... you might get wet). Turn the compressor off and note the water level in the hose ..... come back in an hour and note that the water level in the hose really hasn't changed. An alternative method involves a drinking straw and a 12oz gin & tonic! lol? Works the same way in the lake ..... the key is to be sure the connections are air tight and the air-hose/bubbler line connection is below the level of any potential ice.

Next best thing to a crank-up dock!

[Purple Hays]

I just got back from installing my bubbler system. It appears to be operating just about perfectly. The only thing I need to do is flush the lines out a little because I wasn't very careful regarding cleanliness. When the pump turns off and water backfills the system it picks up all the little PVC shavings, spider webs and other crud and delivers them to some of the 1/32" holes.

Jimbob, thanks for the advice about check valves. I'll confirm on my setup in case I have to put together more systems for the neighbors (my next door neighbor is using two sump pumps, I'd hate to see his electric bill).

This summer I'll play with hole diameter a little to optimize the air flow.

I don't have a check valve on my setup. My place is in Alton and have not had a problem with freezing lines caused by a power outage. But, I do understand the concern; especially if you are subject to prolonged outages.

I found that the linear compressor itself is tight enough to act as a check valve. When the power fails, water enters the bubbler line; but this is not a problem because the bubbler line is well below any potential ice. The air hose leading from the compressor is connected to the bubbler line at the same 'safe' level below the ice. The water will only rise to about the highest hole in the bubbler line. So, even if the power fails and allows 12" of ice to form around the dock, the compressor just starts up (when power returns), and bubbles start attacking the ice .... no problems.

You can prove this out in the warmth of your kitchen by placing a clear vinyl air hose from the compressor into a 5 gallon bucket full of water. Make sure the hose is straight & vertical, the open end is at the bottom of the bucket, and all connections are air tight. Momentarily turn on the compressor to clear the hose of water (stand back ... you might get wet). Turn the compressor off and note the water level in the hose ..... come back in an hour and note that the water level in the hose really hasn't changed. An alternative method involves a drinking straw and a 12oz gin & tonic! lol? Works the same way in the lake ..... the key is to be sure the connections are air tight and the air-hose/bubbler line connection is below the level of any potential ice.

Next best thing to a crank-up dock!

[Mee-n-Mac]

I just got back from installing my bubbler system. It appears to be operating just about perfectly. {snip}

I think a lot of us with docks would like to know how it worked over the winter and what the electric bill was. Is it possible to keep track of how much juice was used for the bubbler ? Could I ask you to post back in the spring with that number and perhaps cost as well. Ditto for jimbob (again and thx !) and Misty Blue. It would be of interest, as a point of comparison, for those of us who use circulators. Thx.

[Misty Blue]

The LMI compressor draws about 100 watts.
A 3/4 HP circulator draws about 550 watts.

The current price of electricity is about $.15 per KW Hour (NH Elec Co OP, I expect that PSNH is similar). This price includes stranded costs, taxes, transmision, etc. The price that we pay (Fuel charge) for generation is about $.06 of that 15 cents.

The average wholesale price of electricity in NE for the past few months has been over $.10 per KW Hour (I sell the stuff) and we can expect a substancial rate increase. Sorry about that but please note that as the price increases the pay back time for the liniar comprressor ( I got a LMI) will decrease.

Now the math:

Worse case for the liniar compressor... running 24 hours a day:

100W X 24 Hours= 2.4KW Hours X $.15= $.35 per day.

Let's check out a 3/4 HP unit running 6, 8, and 24 hours a day:

3/4 HP=550Watts.

550W X 6 Hours = 3.3KW Hours X $.15 = $.50 per day.

550W X 8 Hours = 4.4KW Hours X $.15 = $.65 per day.

550W X 24 Hours = 13KW Hours X $.15 = $2.00 per day.

Again I expect the price fo juice to go up about 10% t0 20% in the next year.

There are some other considerations. My LMI only opens the ice directly under my dock. I like this because it doesn't clear the ice at my beach where I keep my snowmobiles.

On the other hand Pine Island Guy likes his circulator because it opens up the ice for a big area around his dock keeping his swim raft clear as well.

We'll see how the old electricity bills add up over the winter.

Hope this helps.

Misty Blue.

[longisland60]

I am installing ice-eaters at my property and need to put up thin ice signs. I, too, went into Heath's looking for thin ice signs, but decided $40 was too much money for a sign that I still had to secure to a piece of plywood. So, I decided to make my own.

I called the Department of Safety - Marine Patrol, and they sent me the specs on what the signs need to be, and I'll paint them up on some exterior plywood.

One thing I didn't know is that I am supposed to register the signs with the town. Does anyone know the reason for this? Do they maintain a directory of sorts? It's not for a revenue source, as it will cost me a whole 50 cents to register my sign.

I was also told that the sign should be lighted as well, although the specs call for a reflector. I haven't seen any lights on the signs I have noticed around the lake.

Anyway, I figured I'd pass along what I have learned this past week.

LongIsland60

[jimbob1603]

I went to a sign shop and had a 2 x 3 sign made w/aluminum back. It cost me $45. Its big, day-glo red on a white background; and obvious from 200' away. I bolted it, above the ice/snow line, to the end of my dock.

Never heard of registering a 'Thin Ice' sign. Sounds like another method of 'The Man' checking out your house/waterfront so he can increase your property assessment. What possible benefit is there to a property owner registering a 'Caution - Thin Ice' sign? (other than employing more government clerks to keep track of the signs) I think this is a situation where ignorance is the best policy. Same thing for an aquatherm/bubbler ..... what is the practical intent of registering them?

No lights .... I prefer to use Darwin's Theory and thin the herd. If some drunken/silly person is going to wander around the ice at night, he deserves whats coming to him. When I'm drunk/silly and wandering around the ice at night, I've never seen even one illuminated 'Thin Ice' sign (fortunately, I've not yet been culled out). For Pete's sake, lighting the sign would cost more than running the compressor; which is the reason for the sign in the first place.

[Island Lover]

The thin ice sign does not need a permit.

But the aquatherm does require a permit from the town clerk.

[jimbob1603]

My electric bill arrived (NH Electric Co-Op):

From 12-12-05 through 1-12-06
Total: $32.00 ($20 of that is a fixed cost "Member Service Fee")

The only things running on that meter are two LMI DB150L linear compressors, connected to a thermostat which turns them on/off at 35/45.

Anybody with two 1/2 hp circulators beat that?

[CraigJosph]

try dockbubbler.com. it's a true bubbler, not an agitator, comes with all you need, varying bubble line lengths available... and only uses 55 watts, so just leave it on once cold season starts. unlike some bubblers, don't have to keep bubble line level, it has weights on it and meant to lay on bottom. .. but, do need to keep deep enough so you don't get ice in the lines

[jimbob1603]

Here's what it cost me this winter to run 2 linear compressors:

12-12-05 through 1-12-06
Total Due: $32.00 ($20 of that is a fixed cost "Member Service Charge")

1-12-06 through 2-10-06
Total Due: $28.00 ($20 of that is a fixed cost "Member Service Charge")

2-10-06 through 3-10-06
Total Due: $33.00 ($20 of that is a fixed cost "Member Service Charge")

3-10-06 through 4-12-06
Total Due: $25.00 ($20 of that is a fixed cost "Member Service Charge")




The only things running on that meter are two LMI DB150L linear compressors, connected to a thermostat which turns them on/off at 35/45.

Anyone with a circulator have their bills available for comparison? (not that there is a lot of ice this year)

[Misty Blue]

Jimbob

Your advice saved me a bundle this year! It almost.....makes up for the hot tub!

Misty Blue

[jimbob1603]

Glad to help. Being a thrifty hard-core engineer has its benefits. I hope others can see the savings of a linear compressor vs a 1/2 hp circulator.

Interestingly, the bubbler method is not recommended to keep ice from forming around a boat. Just imagine what happens to the specific gravity of water as cascades of fine air bubbles rise up ....... I'll guess it probably drops to about .25; your boat will sink! So, the Mount is not a candidate for the bubbler method.

I'd still like to see an electrical cost comparison of linear compressor vs. circulator. I've posted my expenses to run two compressors for the winter .... just waiting for someone to report how much they spent to run their circulator.

Hey ... is that offer for a tour of the power plant still good?

[T.H.E. Binz]

Have you considered converting to a crank-up dock? It eliminates your de-icing worries altogether!

[jimbob1603]

A crank up is absolutely the way to go; if I was building a new dock. But, I have a very nice 'non-crankable' deepwater 35ft. aluminum dock, a boat lift, and a floating jet-dock.

I didn't want to get involved in redesigning the dock so it could be cranked up; it probably isn't even feasible from an engineering point of view. Besides, I hate mig welding aluminum ... pain in the butt. The boat lift is just too massive/awkward to move out of the water. The jet-dock handles the ice fine ... but it gets 'bubbled' anyway.

I felt that the linear air compressor was the most cost effective alternative to a crank-up.

[ApS]

"...I'd still like to see an electrical cost comparison of linear compressor vs. circulator. I've posted my expenses to run two compressors for the winter .... just waiting for someone to report how much they spent to run their circulator."


In response, here's our electricity use for this winter with no other electricity used, save the two ice circulators. The circulators are supplied and monitored by Winnipesaukee Aquatherm.

FWIW, one of the circulators was controlled by a thermostat, the other was on a timer.

November 04....675kW.....$63.11
December.........------.....------
January............------.....------
February***.....1875kW...$175.31
March..............786kW.....$73.49
April 12............479kW.....$44.79

***Three months combined due problematical winter reading of the meter. (Ice/snow/steep slope).

The electric rate is $.0935/kW, and there's a $5 "Customer Charge" per month, which must be subtracted from the monthly figures.

Hope this proves helpful!

:)

[jimbob1603]

Thanks for the input, APS. For what its worth, I guess the bubbler method is roughly 1/2 the cost to run. I'm glad I made the right decision .... it doesn't happen very often!

[onthebay]

Last winter was the first time running a circulator through the winter. The electric bill was a bit more than I expected. It is on a timer but it seems like the previous owner had it set to run more time than not.
What times do others run their circulators. More at night than during the day? I am not up full time so I would rather error on the side of caution.