Sealing of 55 Gallon Drums

I've read into multiple posts on this forum regarding creating a barrel raft/boat. The design I'm currently working on has a total of 8 plastic drums fastened in a catamaran fashion. Is it necessary to seal the lid of the barrel with something such as silicone? I have read that many people have then drilled a small hole to allow for adjustment in pressure. If the boat will be in the water for most of a day but then out for quite some time (and any water could be dumped then), would it be necessary to use silicone, will it actually leak water that fast? I ask mainly because it would be a lot easier if the plug could be screwed and unscrewed to adjust ballast and change for pressure before every trip. Thanks a Lot!

 

Plastic drum lids form a liquid tight seal when tightened all the way because.... they would be pretty useless otherwise. If you are a belt n' suspenders kinda' guy, you can glue or sealant up the lids if you want to but its not necessary.

 

Welcome to the forum.

Quite the controversial subject for a first post.

My opinions and why

Don't silicon the plugs. A good rubber gasket will stop all leaking and it can be opened and resealed repeatedly. Silicon build up will prevent a seal in just a few cycles

They will maintain buoyancy with one open hole either at the top or bottom. If you take a dry clear glass and push it upside down into a sink full of water you will see that the inside stays dry. Or push it right side up into the sink and it will not fill with water until the rim is submerged. However if a second hole is punched into your barrel then buoyancy is quickly lost.

Plastic barrels are initially sufficiently flexible to adjust to pressure changes. As they age they become brittle and crack easily; either from impact or changing pressure. They should be replaced every few years before they start decinigrating.

As a safety precaution, stuff as much lightweight post catastrophe buoyancy material as possible into the barrels. If the opening is large enough, empty water bottles with their lids screwed on tightly work well. As would strips of foam.

We are curious as to your design. Care to share it with us?

Good luck

 

You said adjust ballast with water in your barrels. You do not want water sloshing around, what is called the free surface effect. It will make your vessel less stable as things get rolling.

 

Thank you for the responses! 1. So would you advise to have the gasket and drilling a small hole? 2. The stability is real news to me, I was under the belief that adding in some water would lower the center of mass so it would be more stable but I definitely could see what you're saying. What do you advise I should do instead? Here is one of the rough drafts I have with me. P.S the idea is to possibly split it at 8 ft length which is why there is 2 2x6's there, so it could be transported in two segments and reconnected at location. This is because I don't have a trailer to carry that long of vessel.

 

I can not recommend adding any holes to the barrels. Good sealing twist off plugs should suffice. Open them whenever there appears to be pressure distortion of the barrels, then reseal.

Ballast is not often used to increase stability of pontoon supported vessels. Keeping the superstructure light and the pontoons far apart are more effective.

What is the intended use?

 

I am new to the Forum as well,

Hello Everyone!

My 2 cents: I'd use drums without removable lid, the screw-in plugs seal as they are - no further action needed.
If you have the drums already I would discard the metal clamps (corrosion sooner or later - at least when used in salt water) and weld them shut (peace of mind) - welders are cheap and only little practice is needed to weld PE. Search for "hot air plastic welder", you should find something decent for under 100$.

Considering the 2 options above, and judging by your "plans" I'd throw the drums you have and get some without removable lid.

 

Thanks for the replies! I plan on using this somewhat frequently in the summer for floating down river nearby, and also taking on small lakes.

 

Do you think the current design will have enough stability? And is their enough support. On the design you might be able to make out on each half of the boat there is a footer and header 2x6 x6' along with (4) total 2x6 x 8' for securing drums. And then 2x4's in between the braces after each barrel and a single 2x4 in the middle of the two "pontoons" Thanks a ton!

 

Amoe,

Welcome to the forum.

This looks like a reasonable design, good for you.

I have a number of concerns however:

You need a design weight.
OR
You can calculate it in reverse and see if you have enough floatation.
You'll need 300% more buoyancy than gross weight.
Each barrel has ~200kg ( ~440 pounds ) of buoyancy.
8 barrels is about 1600kg (~3500 pounds ).
1600/3 = 530 kg or 1170 pounds gross weight.
That includes barrels, structure, people, dogs, provisions, wood stove, everything.

My other concern is barrel collapse or deforming due to lack of seal.
So, I would attempt to seal them.
The barrels are partially water cooled and out of the sun hopefully.

I would not use added water as ballast.
Distribute your load to balance the vessel instead.

I think breaking it in the centre for transport is not a good idea.

Please don't trust my calculations above, you must do your own.

Great project!

 

Thanks for the comment! I have run numerous calculations, and for the most part, I don't think I'll have a problem going over the 1/3 displacement, but I was thinking of occasionally approaching the 1/2 mark. Is this definitely not wise to do? I've read in many places that people have used up to or in rare cases even slightly more than 1/2 of their potential displacement. I'm definitely convinced I'll pass with the water as a ballast idea too.

 

You are most welcome.

You can approach 1/2 but your risk level usually exceeds expectation.
The reality in a catamaran with barrels is the diminishing buoyancy as they submerge past half way.
One cannot account for all the simultaneous loads that may occur.
Rain loading, snow loading, wind loading, a flooded barrel, a rescue from a sinking boat.
The list is endless and unpredictable.
However, from what you describe, it may be possible to exceed 1/3 loading.
But, if one side submerges, the outcome is not forgiving.
As Clint would say, "Are you feeling lucky punk?
Well are ya?"

 

Thanks, I definitely get the loading now.
Here is my next dilemma, I would really like to have this 6' x 16' but in order to do so would have to have in 8' length sections. I could 1) Makes these two structures than barrel bolt them together at the location (My original idea), but now that I think about it some more even though this won't be in any sort of rough conditions it could start ripping and pulling out of the 2x6 fairly easily. 2) I could essentially keep them two separate rafts where on the ends there are a few U bolts that could be strapped together allowing them to move slightly independently and cover edges with something like a pool noodle so they casually slide back and forth. Or 3) Some type of removable screw/latch system that would attach to multiple points on each raft not just at the header 2x6 but struts that reach on the sides and under to other support beams. Any ideas?

 

As you suspect your first connection idea would quickly fail. A twelve foot beam on both outside rails would be better. However aligning bolt holes on two bobbing floats is easier said than done. Eighteen foot trailers are not that difficult to obtain.

What is your planned means of propulsion?

 

Ha! Likely just floating downstream, or on non-windy days bringing a few paddles and sticks (to push along the bottom in shallows) and going around a relatively small lake, or out to the middle and parking it.