Thanks for the great forum firstly...

I'm glad I stumbled upon pondboss.

I have my plan for a floating dock on our iowa pond, and I've done all the research several times over. One thing is plaguing me however. I was dumb enough to post about it on facebook, and now I have tons of people telling me if I don't fill the plastic barrels with foam, they'll leak air allowing water in, and sink.

Are you folks having trouble with this, or are they paranoid. Keep in mind, none of the dozens of people that suggested that actually have a pond or a floating dock, but many were adamant I was making a mistake by leaving the drums empty.

That said... Is leaving them empty a problem? Is there a great way to seal the bungs when screwing the plug cap in to avoid this?

If they have to be filled with foam, what's the best option when on a budget?

Thanks in advance folks. Much appreciated.

-michael

I've never built a dock using plastic barrels either, but I don't think I would worry about filling them with foam. I imagine that would be highly expensive. The bungs themselves use a rubber type seal, so I would probably use some silicone on the threads and crank em' down tight.

Got two of em if anybody want them for free. Send me a pm

Here's something for you to read:

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=350332&page=1

I built my floating dock in 11/2008, using plastic barrels. A good bead or two of silicone around the bung threads and they've been good for almost 7 years now. Paint them silver or white to reflect the UV rays to slow degradation.

i read that... sounds right up my alley.

so you're leaving yours in the water year round? we typically can get as much as 12" to 14" of ice, so this would be no problem leaving it in? or should i plan to yank it?

got them all lined up. very kind of you to offer though. thanks!

My dad has a dock on barrels and it has been in the water for 5 years now with 0 issues.

We built two docks with barrels in 2003 and have had zero trouble with them. The wood is taking a beating in the sun. We used plumber's dope on the bungs as it does not harden like silicone will over the years.

Chaos,

I also have a small floating dock made with plastic barrels. No foam in mine, in water year round, been that way for 5 years. We don't get as much ice as you though! A few inches most years. And that is usually intermittent.

Best of luck, whatever you decide.

Cmm

To piggy back on this topic, is there a general rule of how many barrels are needed for a certain size dock?

I'm thinking about doing an 8'x8' or slightly bigger.

Chris, do you have an idea of how much of the barrels you envision being visible above the waterline when the dock is floating, with or without occupants?

Hadn't though about that but I'm not concerned about seeing a lot of the barrel. I'd like to put a feeder and possible hold 3-4 people so around 1000 lbs max i'd imagine.

Guys this dock of mine is 16X16 with a 60"X16 foot gang way.

As you can see here there is 12 55 gallon barrels used and I used a 2X12 for the outer skirt of the dock. for me I would have loaded the barrels 1/3rd full of water before I sealed them up.

Now why would I have added water to the barrels? That would be a total of about 220 gallons at 10#'s per gallon. You would have to get 2200#s of weight to move for the dock to bounce or jounce around. You would be lifting water on one end and pushing the water in on the other and so on.

The dock floats very high even with 10-12 people on it. 99% of the time we have five people on the dock.

PT material is about 35#s per cubic foot.

Cheers Don.

My blue barrel dock is 10'x10'. I don't pull mine out in the winter, and we usually get 12-18 inches of ice. I've built several and never had any issues.

Mine is built like a deck you would have on a house. It has 2x10 bands, and 2x10 joists on 24 inch centers. The decking is 2x6s spaced about a 1/4" apart.

A 55 gallon blue barrel is approximately 24 inches in diameter and 35 inches long. I have 15 barrels under this 10'x10' deck/dock -- five rows (each approximately 24 inches wide) of 3 barrels each (approximately 9 feet in length) that are floating between each set of joists.

I did seal the barrel bung plugs with a tiny bit of RTV to keep them from possibly unscrewing. But, I also drilled about a 1/16 inch hole into the middle of each bung seal to allow for pressurization changes as the temperature changes. If you don't do that, the barrels will begin to collapse on themselves in the winter.

My barrels are not fastened in any way to the deck/platform. They simply float beneath and between the joists. Once the basic deck is in the water, it floats enough by itself to where, with at least one friend, you can start putting barrels under the platform. We pushed mine in with the front end loader of my tractor, and then lifted it to get the first few barrels under it. Once positioned, they will stay between the joists. I rotated mine so that the bung is at the top on all of the barrels. That allows the barrels to breath without taking in any water. The tiny hole is about 10 inches above the water line.

This particular dock has now been in the water 6 or 7 years without any issues what-so-ever. It is very stable in most cases. I do have one occasional visitor who weighs about 350 lbs who makes me nervous when he walks towards any of the corners. But, it is no problem to have five or six normal size adults on there at any one time.

I do not have mine anchored, except by the walkway. The 4-foot wide walkway is made from three 12-foot long 2x8s, decked with 2x6s. I used heavy duty outdoor gate/fence hardware to fasten the walkway to the land and the deck. I used my post hole digger to go down into the shoreline about 36 inches, about 3-4 feet back from the water's edge. I filled the holes with concrete and put long-large eye bolts at the top. They mate up with the gate hardware.

Good luck.
Ken

With 15 barrels under my 10x10 floating deck, the barrels are about half submerged.

My above dock is 2X6 joist and full 2X6 decking planks. I can see how 2X10 would need the extra barrels.

Cheers Don.

I think this is one of those areas where precision is in the eye of the beholder, or in this instance, the eye of the dock builder.

I'm all about simple, so a gallon of water weighs approx 8 lbs, assume 50 gallons in each drum, that's 400 lbs of flotation capacity per drum, with the drum nearly submerged.

I agree with Don in that adding water will stabilize the dock somewhat, so allowing for a minimal flotation height, and a loaded platform of 1400 lbs, (including the weight of the superstructure itself), that works out to 4 barrels...empty. And probably bobbing like a cork whenever you try and move around.

8 x 8 is pretty small, especially when the occupants all want to be on the same side at the same time... I would go bigger, with more barrels, to help alleviate the tendency to pitch and roll dramatically.

Chris, you mentioned wanting a feeder and also wanting to hold maybe 4 people and so I will suggest you go bigger. The feeder stands I have are 5 x 10's and my Texas Hunter feeder takes up most all of this area when I am filling the feeder. These are stationary, but if it was floating, I would want a bigger area, especially if I wanted room for people. And 9-55 gal drums will handle my 12 x 16 floater with several people without any problems. hope this helps.

Tracy

Chris, I built an 8x8 using 4 plastic barrels. With even 1 person it isn't real stable. The next one will be something like 12x12 and the barrels will be partially filled with water. Simple to build, my nephew and I put ours together in about 2 hours.

I like the adding water part. If you think about it, empty cargo ships take on ballast for stability. I'm thinking it's the same concept.

This does help a lot, it also makes it much easier to get the barrels in. On my dads dock we put it in the water with a few barrels to float it in to position. The additional barrels were pretty filled most of the way with water so they set down low, floated under the dock with the bottom bung out, then we used the air compressor to blow air in to them and raise them back up and displace the water out to the level you want. Once they are where you want them you can put the bottom bung back in and call it good. We havent had a single barrel sink in 5 years now.

I'm coming out with quite a bit more of buoyancy for a drum. I came out with ~571 lbs of lift.

Finding the volume of the cylinder in cubic feet. Which I'm using someone else supplied info of it being 24" dia. x 35" height. So A=πr^2 or A=3.14x1^2=3.14. That was for circle area then times height in feet 2.9166666 which came out to be 9.158 x weight of cubic foot of freshwater 62.4 lbs gave me 571 lbs of lift.

To figure out the "ride height" would require a lot more math but to err on the side of caution I would say each barrel has a max buoyancy of ~550 lbs

Hope this helps

It depends on the size of the barrel. Water weighs 8.3# per gallon. So, a 55 gal barrel will float 8.3# x 55 - the weight of the barrel.

But, that's at complete submersion. To keep many docks out of the water only count on 50% of the barrel being submerged until the dock "skirt" wood touches the water.

I've been taught to compute buoyancy based off the weight of a cubic foot of displaced water fresh being 62.4lbs salt being 64lbs. Either way like you said that's at its maximum so I also would recommend that whatever you figure its lift to be to divide it in half to err on the side of safety.

gallon to cubic foot table

One gallon of water weighs 8.3453 pounds. One cubic foot of water contains 7.48052 gallons. The weight of one cubic foot of water is 7.48052 gallons times 8.3453 pounds, which equals 62.42718356 pounds of water per cubic foot.

This 12 x 10 dock was built with (6) 55 gallon drums.

2 x 8 rim with 2 x 6 joists and 5/4 x 6 treated wood.

The ramp is 4 x 10 with one barrel underneath.

ken,

i'm not sure i understand. won't the hole, even though small, eventually take on water? who cares if they suck in a bit in the winter? ...or does that create/allow a problem?

-michael

How dumb an idea would it be to fill those drums with those cheap styrofoam packing peanuts and not worry if they leak?

Chaos,

A number of years ago I built a barrel dock. The barrels would go from plump in hot weather to mis-shapen when it got quite cold. I was concerned about the constant flexing - although it probably not a problem.

With that said, the 1/16th inch hole keeps the barrels in my present dock in their normal shape. I'm sure there is some condensation in them, but not enough to worry about. If nothing else, it is more esthetically pleasing to look at.

The holes are probably at least 10 inches above the water line, and even in a driving rain I doubt they would take on much, if any water.

Ken

Those peanuts might designagrate if water got in or walk out of the barrel some how. Not a fan of ghost poop