Damage Control Plugs

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sbu22

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Mar 16, 2011
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1,253
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US
Vessel Name
Panache
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Viking 43 Double Cabin '76
I’m finally getting around to installing DC plugs at each of my through-hull fittings. The intention is to wire the appropriate size plug to each through-hull for easy access if/when an emergency arises.

Having spent years in the USN, attending multiple classes and simulators, I’ve practiced with plugs and wedges a bunch – all with steel hulls and monel/bronze/ and who knows what else as the base material. The questions that follow are all in the context of a fairly typical F/G rec boat.

Question 1 – what is the correct size for the plug versus the inner diameter of the fitting? The plugs all have a taper. So, for the sake of discussion, what’s correct for a ¾” id fitting? ½” to 1”? Is there a “rule of thumb”?

Question 2 - There are DC plugs offered in soft wood, redwood, closed cell foam, etc., etc. Is there an optimum material?

Question 3 – When employing a DC plug, do I want a 5# hammer or a rubber mallet? Or, something else? Imagine the correct answer goes back to material of the element being plugged.

It took me a while, but I finally figured out that the contents of the good old USN DC tool roll may not be the best application for a rec boat.

As always, the TF input is greatly appreciated.
 
Frankly I am more comfortable making sure that there are bags of different plugs in strategic areas. If closing your through hull doesn't do the trick because of a busted hose, I would be worried about dealing with a hole that is not necessarily the size of the through hull.
 
I’m finally getting around to installing DC plugs at each of my through-hull fittings. The intention is to wire the appropriate size plug to each through-hull for easy access if/when an emergency arises.

Having spent years in the USN, attending multiple classes and simulators, I’ve practiced with plugs and wedges a bunch – all with steel hulls and monel/bronze/ and who knows what else as the base material. The questions that follow are all in the context of a fairly typical F/G rec boat.

Question 1 – what is the correct size for the plug versus the inner diameter of the fitting? The plugs all have a taper. So, for the sake of discussion, what’s correct for a ¾” id fitting? ½” to 1”? Is there a “rule of thumb”?

Question 2 - There are DC plugs offered in soft wood, redwood, closed cell foam, etc., etc. Is there an optimum material?

Question 3 – When employing a DC plug, do I want a 5# hammer or a rubber mallet? Or, something else? Imagine the correct answer goes back to material of the element being plugged.

It took me a while, but I finally figured out that the contents of the good old USN DC tool roll may not be the best application for a rec boat.

As always, the TF input is greatly appreciated.

Soft wood tapered plug, piece of pool noodle, rags, nerf football etc. Any of these at the ready near through hull will work. Mallet or a scared mans fist..
 
Pencil, screw driver, wooden spoon, chop stick etc wrapped with a towel, rag, wash rag, pounded into the hole.

Worked, works for me.

Just saying.
 
An old t shirt and a screwdriver to push it in may be a more intuitive approach.
What if the hose breaks off ragged, and the clamps are frozen or underwater and inaccessible?
I keep a bucket in the ER with some various rubber balls and a couple golf balls, some rags, tie wire and pliers and a hammer and a screwdriver. There is a couple of tapered wood plugs too, but I wonder how much collateral damage might occur if they had to be driven in smartly.
 
You might be overthinking this a bit, as friction fit tapered plugs in heat exchangers are good up to 200psi and 400F by ASME PCC-2.

That said, I too have fond memories of wet trainers, DC kits and band-it clamps. So...

I have a smaller version of a DC bag with different sizes and material (wood & micarta) plugs and wedges. A chain wrench, a Nerf football, a couple of different types of Belzona (1111 & 2311), electricians self fusing tape, and some polyurethane resin repair tape.

The reality, is I will not likely ever need them. My quickest fix in the Navy was with a pencil, and once at a mill with a wood chip. I'm not giving details of either. ?

Edit: I still have one of those cool lifeboat clamshell clamp repair dealies that I'm sure no one in the history of the Navy has used successfully.
 
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Actually, Spy, with a night to sleep on it, probably over thinking a lot.

Good ideas here - appreciate it!

The clamshell clamp thing remains a mystery - I always thought they existed to supply a reservoir of "lead pipe" questions for qualified checkouts.
 
That would be "qual" checkout.
 
Replacing the hoses might be a good idea if they are older than a few years. Ind I would make sure the seacocks work.

I would be more concerned with a hole in the hull and of course you don't know how big or what shape that hole will be. You also don't know if you can get to it without endangering yourself by getting stuck somewhere with rising water.
 
Who, besides me, has a collision mat aboard?
 
No collision mat, but I keep a heavy tarp that will wrap around the bow, some 1/8" & 1/4" plywood sections, lots of pillows and various length of wood to hold them in place.

Most of the high risk collision points are sealed chambers in the bow (filled with ballast), or water tanks on the side.
 
No collision mat, but I keep a heavy tarp that will wrap around the bow, some 1/8" & 1/4" plywood sections, lots of pillows and various length of wood to hold them in place.

Most of the high risk collision points are sealed chambers in the bow (filled with ballast), or water tanks on the side.

Your setup IS a collission mat.
 
Your setup IS a collission mat.

Yes - I'm surprised that more pleasure boats aren't designed this way. The cost at the time of construction is minimal. You only lose a bit of storage space under the vee berth. There is an inspection hatch to check for a breach or to adjust the amount of powdered ballast. The big built in fibreglass water tanks along each side cost nothing other than a bit of planning at the design stage.
 
Forespar offers conical foam rubber plugs that fit most through-hulls. No need for different sizes. No need for hammer - just push and twist into the hole. While I never needed to use one, we did keep a couple on board.
 
Maybe some of that "as seen on TV" slap on water proof tape?? Hmmmm, who's going over the side to apply it.
Seriously, after Irma, there was a good size boat that rubbed its bow against the concrete wall, a number of times. Before moving the boat, the owner/crew artfully applied a number of layers of that 'slap on tape', prior to moving it to the yard. I guess it worked.
 
Most municipal public works couldn't function without polyurethane tape or Robar clamps. The water would stop running.
 

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