Boat Forum / Building / October 2008

The old fashion way was to whittle a tapered wood plug and drive it in
the hole. The wood will swell and make a tight joint. A more modern
way is two big washers, or plates, depending on the size of the hole,
gaskets, bolts and sealant. On a ship they will sometimes pour a
compartment half full of cement. If you can keep the water from coming
in for a while you can grind the inside to clean metal and apply a
fiberglass patch. Needs to be dry though. You can also get epoxy putty
that can be applied under water.

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

Jim,
This could be a very serious problem. You need the entire hull surveyed with
ultrasound to determine plate thickness. You may very wll find this is the
tip of a large iceberg so to speak and the entire boat maybe unsafe. Please
take this seriously and pull it out of the water immediately.
Steve

Hi all,
  No rush for answers on this one, but I'm sinking... I found a bit
of water in the bilges and put it down to something benign, but on
inspection, found a blister on the paint inside the hull, which when I
burst revealed a ~2mm square hole in the hull on the bottom of the
boat. I've plugged it with gaffer tape, rubber mats and bits of wood
for now, but has anyone got any neat ways of fixing this without
taking it out of the water (boat is a 20 tonne wrought iron/mild steel
dutch barge, and a proper repair job would be ~£700)?
 I'm thinking a bolt with a big rubber washer on both sides and
liberal use of silicon sealant. I'm hoping the rot is very localised.

cheers

Jim
UK

Off the top....find a big black rubber plunger cup and handle.
Dive this onto the outside of the rust through hole in the hull.
Build the hole edges in with a MIG torch from inside.

If you try this - have someone make a movie please?   :-)

Brian W

On Jul 21, 7:23 am, "jimchuf...@googlemail.com"
<jimchuf...@googlemail.com> wrote:

I'd get it checked with ultrasound, if the rot is extensive it needs a
proper repair ASAP.

cheers,
Pete.

On Jul 21, 4:23 pm, "jimchuf...@googlemail.com"
<jimchuf...@googlemail.com> wrote:

Hi Jim,

Blistering paint in the bilge pump is often caused by stray current
which causes electrolysis corrosion. If you have these signs then
chances are your boat is being effected and  unless something is done
about stopping or deterring the stray current the corrosion to the
hull won't stop.

I have found a product that can stop this altogether and can protect
the boat. Go to http://www.seabis.net and you can find out the cause
and effect and all about the product- Angeleika1

On Jul 20, 11:23 pm, "jimchuf...@googlemail.com"
<jimchuf...@googlemail.com> wrote:

is the hole on a seam might be old porosity. its about 1/16 of an
inch  in a 3/16ths thick hull  from the sounds of the survey you got
some good steel. so get a buzz box and weld the darn thing shut. get
good penetration head over the side and look at it if its a good weld
paint it go back on grind the weld flush on the inside and prime and
paint.  I assume from reading you are restoring the boat so it would
make me think of needle gunning the bilge and getting some good primer
and paint down. then i would not have to worry about how much rot i
have, i would know. checking out your zincs would be a good idea and
making sure they are welded to the hull in full contact with the
steel.
examining them would tell you if you have an electrolysis problem.

Since it is just a very small hole (less than 1/8 of an inch) in mild steel
hull you can just drill it out with an appropriate size drill bit and tap it
to be able to screw in the correct size threaded bolt/screw to use as a
plug. You have to make sure though before starting that you have all the
necessary tools (drill bit, correct tap with wrench and correct size
plugging screw) on hand since you have to accomplish the repair process
quickly to avoid getting in too much water. After you install the plugging
screw it's pretty much almost like a permanent repair and you can even weld
it in place if you want.

Hi all,
  No rush for answers on this one, but I'm sinking... I found a bit
of water in the bilges and put it down to something benign, but on
inspection, found a blister on the paint inside the hull, which when I
burst revealed a ~2mm square hole in the hull on the bottom of the
boat. I've plugged it with gaffer tape, rubber mats and bits of wood
for now, but has anyone got any neat ways of fixing this without
taking it out of the water (boat is a 20 tonne wrought iron/mild steel
dutch barge, and a proper repair job would be ~£700)?
 I'm thinking a bolt with a big rubber washer on both sides and
liberal use of silicon sealant. I'm hoping the rot is very localised.

cheers

Jim
UK