Chris wrote:

I've got some visible cracks at the bottom of my hull on my 16ft
runabout. This past summer when using the boat I was getting a bit
of water in it after having it sit for a while in the water (the
bilge pump easily took care of it). I'm now thinking that these
cracks may be the cause and water slowly seeps into the boat.

Now, my question about how I should attempt to fix this giving the
following considerations 1. It's an old boat. 2. I use it a 4-5
weekends a year. 3. I don't want to spend a lot of money as its not
worth it.

snip

Based on the above, you need a functional repair, but this is no gold
plater, so the finish of the repair can basically be slim or none;
however, the repair should do a proper job.

My solution will be prejudiced since I run an epoxy shop.

IMHO, polyester is for shower stalls, not boat repairs.


1) Buy a 1 qt kit of laminating epoxy, a yard of 17 oz biaxial, knitted
glass, some 2" chip brushes and some latex gloves.

2) Flip boat upside down and grind back from the crack about 4" using a
24 grit, right angle sander. Leave the sanded surface ROUGH, the rougher
the better.

3) Lay 2 layers of 17 oz glass using the 2nd layer to over lap the first
layer about (1")-(1-1/2") all around.

4) Let cure 48 hours, then scuff up with 24 grit sander and lay 2 more
layers of 17 oz glass as above.

5) Wait 48 hours then fair edges of patch fair with boat using 24 grit
sander.

6) Flip boat over, scuff up inside and lay 2 layers of glass, same as
outside.

7) Get a beer, maybe 2.

8) Allow inside patch to cure about 72 hours, then relaunch boat and enjoy.

Notice the lack of labor intensive finish work?

OK, if you are fussy, fair out edges of inside patch, otherwise, forget it.


Lew

Lew Hodgett wrote:

so the finish of the repair can basically be slim or none;
however, the repair should do a proper job.


Very true

My solution will be prejudiced since I run an epoxy shop.

IMHO, polyester is for shower stalls, not boat repairs.

Since the rest of the boat is polyester, why should a patch be stronger
than the rest of it? I do use WEST for little things, but a patch
should be the same material the rest of the boat is made of.


Step 1)
Since the boat was built from the inside, I would just do the repair on
the inside. This way there's no finish work on the outside.

Steps 2-6) Grind, mat, roving, mat, roving, gloves, resin, hardener,
roller, don't make a mess. . .


7) Get a beer, maybe 2.

Admire your work while drinking beer.

8) Allow inside patch to cure about 72 hours, then relaunch boat and enjoy.

Notice the lack of labor intensive finish work?


Jim

Jim wrote:
Since the rest of the boat is polyester, why should a patch be stronger
than the rest of it? I do use WEST for little things, but a patch
should be the same material the rest of the boat is made of.


It's not an issue of strength of the material itself, but of bonding
strength. What you are making is called a "secondary bond" meaning that
it's trying to stick to something that's already cured.

Polyester is OK for lay-ups but it's bonding properties are poor, even
to polyester.

It is cheaper, but unless you are really dedicated to squeezing pennies,
and have already wrung the expense out of everything else on the boat,
and don't have any other little projects that epoxy would be best for,
then it's false economy IMHO.

Fresh Breezes- Doug King