Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Aug 2006
Posts: 22
Default 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!!!

  #2   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Sep 2006
Posts: 8
Default 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!!!


  #3   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 159
Default 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

  #4   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Aug 2006
Posts: 22
Default 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


  #5   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 348
Default 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


  #6   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Aug 2006
Posts: 22
Default 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


  #7   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 348
Default 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
  #8   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Aug 2006
Posts: 22
Default 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


  #9   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Oct 2006
Posts: 4
Default 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


Stitch and glue driftboats are a special case, that make
a good general point, I think.

A driftboat (a dory that drifts down a river) gets its
bottom pounded like no other boat. No matter how
much glass you put over the bottom and chine, cuts
in the glass skin will inevitably expose the plywood.
Then the plywood wicks up moisture, which gets trapped
almost forever, between the glass skins.

Some guys (montana boat builders dot com) have essentially
solved that problem (for stitch and glue boats anyway) by
puting hot spray truck bed liner on the outside.

Another way to deal with it is to use plastic honeycomb core
for the bottom panel, instead of plywood. If you do that, you
need a little extra glass, to stiffen the panel sufficiently.
But when and if the skin gets cut, the moisture does not
wick sideways into the honeycomb.

For me it's all about do-it-yourself boatbuilding, not
necessarily with wood. Plywood makes good side panels
on dories.......a place that doesn't get pounded.
For bottom panels on driftboats, I don't like plywood.

Plascore (or nida core) might be a better core for
any homemade boat.

  #10   Report Post  
posted to rec.boats.building
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 813
Default the raging debate of marine plywood / fiberglassing / etc

On 15 Oct 2006 08:23:29 -0700, "Leaks"
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


Stitch and glue driftboats are a special case, that make
a good general point, I think.

A driftboat (a dory that drifts down a river) gets its
bottom pounded like no other boat. No matter how
much glass you put over the bottom and chine, cuts
in the glass skin will inevitably expose the plywood.
Then the plywood wicks up moisture, which gets trapped
almost forever, between the glass skins.

Some guys (montana boat builders dot com) have essentially
solved that problem (for stitch and glue boats anyway) by
puting hot spray truck bed liner on the outside.

Another way to deal with it is to use plastic honeycomb core
for the bottom panel, instead of plywood. If you do that, you
need a little extra glass, to stiffen the panel sufficiently.
But when and if the skin gets cut, the moisture does not
wick sideways into the honeycomb.

....


Which reminds me - a Lake patrol man showed me the bottom of his
airboat one day. To allow it to dock right up the ramp onto the hard,
they fitted the bottom with a low friction plate - either high density
polyethylene - or it might even have been teflon.

Brian Whatcott Altus OK


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Just a few names... John Smith General 0 May 2nd 04 11:32 PM
Marine Plywood Suppliers in Atlanta Ian Boat Building 1 April 19th 04 08:52 PM
Essentials of a Marine Boat Alarm System Rick Curtis Electronics 19 February 23rd 04 09:42 AM
watertight coating for marine plywood deck Ken Fraser Boat Building 8 February 10th 04 04:16 PM
Plywood & Fiberglass deck Adam Boat Building 4 September 27th 03 12:13 PM


All times are GMT +1. The time now is 03:31 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 BoatBanter.com.
The comments are property of their posters.
 

About Us

"It's about Boats"

 

Copyright © 2017