the raging debate of marine plywood / fiberglassing / etc
 

hi all,

i've been searching through the group .. i keep finding conflicting
opinions.. hoping i can ask my exact question and get an answer :)

i just bought a 2003 bayliner 2150 classic (21.5 foot ski boat
basically). the previous owner left the boat out in the sun/water/etc
for 3 years without a cover!! the carpet is trashed. i ripped it all
up tonight. low and behold, the plywood is rotten.

question1) how do i remove the rotten plywood.. do i take a saw and
just cut the wood out.. or is it screwed in somewhere.. do i need to be
careful *where* i cut? what is underneath the plywood.. more wood
(that is probably rotten as well)??

question2) i've read that if you fiberglass over plywood, sometimes the
fiberglass cracks and lets water seep into the plywood and rots all
over again.. ?? myth or truth?

question3) so.. what i really want to do is have plywood and then a
paint with sand in it to give a grip to the feet when walking.. and be
done with it.. what plywood/paint/anything in between the two should i
use?


many thanks!!!

the raging debate of marine plywood / fiberglassing / etc
 

Hi Kyle,

This is more sailboat related, but if you are looking for tips on
restoring a boat, please click your way over to www.triton381.com this
guy (Tim) restored a very old sailboat into something spectacular and
DOCUMENTED every aspect of the refit including plywood, decks etc. I
use his site daily (and I am just in the planning stages of my refit)!

Good luck

Tom
Only 2 things make a man crazy - women and boats

kyle wrote:
hi all,

i've been searching through the group .. i keep finding conflicting
opinions.. hoping i can ask my exact question and get an answer :)

i just bought a 2003 bayliner 2150 classic (21.5 foot ski boat
basically). the previous owner left the boat out in the sun/water/etc
for 3 years without a cover!! the carpet is trashed. i ripped it all
up tonight. low and behold, the plywood is rotten.

question1) how do i remove the rotten plywood.. do i take a saw and
just cut the wood out.. or is it screwed in somewhere.. do i need to be
careful *where* i cut? what is underneath the plywood.. more wood
(that is probably rotten as well)??

question2) i've read that if you fiberglass over plywood, sometimes the
fiberglass cracks and lets water seep into the plywood and rots all
over again.. ?? myth or truth?

question3) so.. what i really want to do is have plywood and then a
paint with sand in it to give a grip to the feet when walking.. and be
done with it.. what plywood/paint/anything in between the two should i
use?


many thanks!!!

the raging debate of marine plywood / fiberglassing / etc
 

kyle wrote:
hi all,

i've been searching through the group .. i keep finding conflicting
opinions.. hoping i can ask my exact question and get an answer :)

i just bought a 2003 bayliner 2150 classic (21.5 foot ski boat
basically). the previous owner left the boat out in the sun/water/etc
for 3 years without a cover!! the carpet is trashed. i ripped it all
up tonight. low and behold, the plywood is rotten.

question1) how do i remove the rotten plywood.. do i take a saw and
just cut the wood out.. or is it screwed in somewhere.. do i need to be
careful *where* i cut? what is underneath the plywood.. more wood
(that is probably rotten as well)??

question2) i've read that if you fiberglass over plywood, sometimes the
fiberglass cracks and lets water seep into the plywood and rots all
over again.. ?? myth or truth?

question3) so.. what i really want to do is have plywood and then a
paint with sand in it to give a grip to the feet when walking.. and be
done with it.. what plywood/paint/anything in between the two should i
use?


many thanks!!!

You need to remove the rotted plywood. If it's rotted any screws
shouldn't be that much of a problem, the screws should pull right
through. I suspect underneath you'll find the bilge (obviously) and
flotation material that is probably waterlogged as well, it will need
to be replaced as well. Fiberglass, properly applied to plywood, should
last a long time. Avoid very thin wood as it may flex too much, causing
the fiberglass to crack allowing water to get in. Try a local marine
shop for paint and the sand additive, but outdoor carpet is usually
easier, cheaper and looks better. I have seen people coat the floor
with gell coat that has been thickened and applied with a roller to
give a rough finish, too rough it'll take the skin off your bare feet,
so most sand it down some, but this finish looks pretty good.

John

the raging debate of marine plywood / fiberglassing / etc
 

thanks so much for responses.

i am going to take a chunk of rotten plywood out tonight and see if the
stringers are rotten. if they are, i don't know what to do.. pay $1K
for a professional? i am no match for replacing stringers.. i'm a
newbie..

if stringers are okay.. then i will get marine plywood, roller two
coats of epoxy on both sides and if any wood needs jointing, do butt
joints, sand to 80grit, then apply Skid-no-more to the top surface, and
be good as new.

does this sound like an okay plan? i want to do away with carpet
because of the rot factor..


Capt John wrote:
kyle wrote:
hi all,

i've been searching through the group .. i keep finding conflicting
opinions.. hoping i can ask my exact question and get an answer :)

i just bought a 2003 bayliner 2150 classic (21.5 foot ski boat
basically). the previous owner left the boat out in the sun/water/etc
for 3 years without a cover!! the carpet is trashed. i ripped it all
up tonight. low and behold, the plywood is rotten.

question1) how do i remove the rotten plywood.. do i take a saw and
just cut the wood out.. or is it screwed in somewhere.. do i need to be
careful *where* i cut? what is underneath the plywood.. more wood
(that is probably rotten as well)??

question2) i've read that if you fiberglass over plywood, sometimes the
fiberglass cracks and lets water seep into the plywood and rots all
over again.. ?? myth or truth?

question3) so.. what i really want to do is have plywood and then a
paint with sand in it to give a grip to the feet when walking.. and be
done with it.. what plywood/paint/anything in between the two should i
use?


many thanks!!!

You need to remove the rotted plywood. If it's rotted any screws
shouldn't be that much of a problem, the screws should pull right
through. I suspect underneath you'll find the bilge (obviously) and
flotation material that is probably waterlogged as well, it will need
to be replaced as well. Fiberglass, properly applied to plywood, should
last a long time. Avoid very thin wood as it may flex too much, causing
the fiberglass to crack allowing water to get in. Try a local marine
shop for paint and the sand additive, but outdoor carpet is usually
easier, cheaper and looks better. I have seen people coat the floor
with gell coat that has been thickened and applied with a roller to
give a rough finish, too rough it'll take the skin off your bare feet,
so most sand it down some, but this finish looks pretty good.

John

the raging debate of marine plywood / fiberglassing / etc
 

kyle wrote:

snip

question1) how do i remove the rotten plywood.. do i take a saw and
just cut the wood out.. or is it screwed in somewhere.. do i need to be
careful *where* i cut? what is underneath the plywood.. more wood
(that is probably rotten as well)??

Remove the plywood in as large a piece(s) as possible, then later use
them as a pattern for replacement.

question2) i've read that if you fiberglass over plywood, sometimes the
fiberglass cracks and lets water seep into the plywood and rots all
over again.. ?? myth or truth?

It depends.

Epoxy provides a water tight bond to wood, polyester resin does not.

Use epoxy for repair work.

question3) so.. what i really want to do is have plywood and then a
paint with sand in it to give a grip to the feet when walking.. and be
done with it.. what plywood/paint/anything in between the two should i
use?

You can use any kind of plywood available if you cover it with epoxy
and glass.


If it were me, I'd use a piece of cheap, 1/2", 4 ply, CDX plywood with
a layer of DB170 (17 OZ, double bias, knitted glass) on each side,
then seal the edges with a layer of 4" "boat tape" (about 6 OZ glass).

It will be bullet proof.

Lew

the raging debate of marine plywood / fiberglassing / etc
 

Lew,

Thanks for the response. Two questions.

1) 4" "boat tape" (about 6 OZ glass) -- is this 6 OZ fiberglass, or is
it something else called "boat tape" (or they are one in the same)??

2) If I fiberglass, then lay marine carpet.. what do you think the life
expectancy of the deck will be with continuous water splashing on the
deck soaking into the carpet?? or should i just do the evercoat
skid-no-more solution.. this is my first boat and i am worried it might
hurt the kids feet? but i don't want to do this whole project over 3
yrs from now either...



Lew Hodgett wrote:
kyle wrote:

snip

question1) how do i remove the rotten plywood.. do i take a saw and
just cut the wood out.. or is it screwed in somewhere.. do i need to be
careful *where* i cut? what is underneath the plywood.. more wood
(that is probably rotten as well)??

Remove the plywood in as large a piece(s) as possible, then later use
them as a pattern for replacement.

question2) i've read that if you fiberglass over plywood, sometimes the
fiberglass cracks and lets water seep into the plywood and rots all
over again.. ?? myth or truth?

It depends.

Epoxy provides a water tight bond to wood, polyester resin does not.

Use epoxy for repair work.

question3) so.. what i really want to do is have plywood and then a
paint with sand in it to give a grip to the feet when walking.. and be
done with it.. what plywood/paint/anything in between the two should i
use?

You can use any kind of plywood available if you cover it with epoxy
and glass.


If it were me, I'd use a piece of cheap, 1/2", 4 ply, CDX plywood with
a layer of DB170 (17 OZ, double bias, knitted glass) on each side,
then seal the edges with a layer of 4" "boat tape" (about 6 OZ glass).

It will be bullet proof.

Lew

the raging debate of marine plywood / fiberglassing / etc
 

kyle wrote:


1) 4" "boat tape" (about 6 OZ glass) -- is this 6 OZ fiberglass, or is
it something else called "boat tape" (or they are one in the same)??

They are one and the same. "Boat Tape" is a generic description of a
light weight glass tape sold in 50' rolls.

2) If I fiberglass, then lay marine carpet.. what do you think the life
expectancy of the deck will be with continuous water splashing on the
deck soaking into the carpet?? or should i just do the evercoat
skid-no-more solution.. this is my first boat and i am worried it might
hurt the kids feet? but i don't want to do this whole project over 3
yrs from now either...

Save your money and forget the carpet.

The glass itself will provide a rough enough surface, just paint it to
provide UV resistance for the epoxy.

BTW, you want to bond the new deck to the stringers with SikaFlex 291.

Have fun.

Lew

the raging debate of marine plywood / fiberglassing / etc
 

OK. Awesome answers. One more question then I'm done for the day :)

When I cut the piece of rotten plywood out from th eboat, then cut a
fresh piece in the exact size.. what do I do first?

1) I fiberglass/epoxy it the 4 coats (seal, bond, fill, finish -- are
all of these needed for what i'm doing??) -- both sides & edges
2) do I need to create any butt-joints to mesh with other sides of
plywood still mounted to stringers?
3) apply a thick coat of sikaflex to the stringer, then lay the glassed
piece down / joint it

?


Lew Hodgett wrote:
kyle wrote:


1) 4" "boat tape" (about 6 OZ glass) -- is this 6 OZ fiberglass, or is
it something else called "boat tape" (or they are one in the same)??

They are one and the same. "Boat Tape" is a generic description of a
light weight glass tape sold in 50' rolls.

2) If I fiberglass, then lay marine carpet.. what do you think the life
expectancy of the deck will be with continuous water splashing on the
deck soaking into the carpet?? or should i just do the evercoat
skid-no-more solution.. this is my first boat and i am worried it might
hurt the kids feet? but i don't want to do this whole project over 3
yrs from now either...

Save your money and forget the carpet.

The glass itself will provide a rough enough surface, just paint it to
provide UV resistance for the epoxy.

BTW, you want to bond the new deck to the stringers with SikaFlex 291.

Have fun.

Lew

the raging debate of marine plywood / fiberglassing / etc
 

kyle wrote:

When I cut the piece of rotten plywood out from th eboat, then cut a
fresh piece in the exact size.. what do I do first?

1) I fiberglass/epoxy it the 4 coats (seal, bond, fill, finish -- are
all of these needed for what i'm doing??) -- both sides & edges
2) do I need to create any butt-joints to mesh with other sides of
plywood still mounted to stringers?
3) apply a thick coat of sikaflex to the stringer, then lay the glassed
piece down / joint it


My answers are based on replacing the entire sole, not just part of it.

You fit the plywood, then glass it totally to encapsulate it, then
finally fit it using the SikaFlex 291.

Finally, you come back and seal the sole to hull joint with a layer of
boat tape.

If you have butt joints in the plywood, seal them with a layer of
DB-170, say 8" wide, on both sides, then come back and finish glassing
the plywood.

The alternate is to use 2 layers of plywood, say 3/8" thick, spacing
the butt joints so they are covered.

Have fun.

Lew

the raging debate of marine plywood / fiberglassing / etc
 

I know it's a little off from what I had mentioned earlier.. but I was
talking with my brother about my plan.. and he said you really should
put carpet down on a ski boat.. well with that in mind...

Could I simply spread 2-3 coats of epoxy (no fiberglass) and then put
the marine carpet down?

Or should I do the full nine yards of 4 coats of epoxy/glass and then
lay the marine carpet over that? What is the fiberglassing buying me?



Lew Hodgett wrote:
kyle wrote:

When I cut the piece of rotten plywood out from th eboat, then cut a
fresh piece in the exact size.. what do I do first?

1) I fiberglass/epoxy it the 4 coats (seal, bond, fill, finish -- are
all of these needed for what i'm doing??) -- both sides & edges
2) do I need to create any butt-joints to mesh with other sides of
plywood still mounted to stringers?
3) apply a thick coat of sikaflex to the stringer, then lay the glassed
piece down / joint it


My answers are based on replacing the entire sole, not just part of it.

You fit the plywood, then glass it totally to encapsulate it, then
finally fit it using the SikaFlex 291.

Finally, you come back and seal the sole to hull joint with a layer of
boat tape.

If you have butt joints in the plywood, seal them with a layer of
DB-170, say 8" wide, on both sides, then come back and finish glassing
the plywood.

The alternate is to use 2 layers of plywood, say 3/8" thick, spacing
the butt joints so they are covered.

Have fun.

Lew