Conference vicki::boats

John,
I've also got an older fiberglass boat that is showing some signs
of a water saturated transom. Mine is about 25 years old and only
14 feet so it isn't worth much anyway, but I've been contemplating
what to do to slow down the problem. This is what I've come up with
on my own, so I ain't guaraneeing it, but it won't cost much to try.

Wait 'til the end of the season and put the boat into a *dry* storage
area, preferably an indoor garage. Remove the motor and all transom
hardware, and the transom cap if it has one (mine does). Clean out
all mounting holes so they can breathe. Now let the boat sit for the
entire winter with as much dry ventilation as possible so the transom
can dry out, possibly a fan or heater may help.

In the spring, first test to make sure the wood has dried completely.
If it looks dry, what you want to do now is seal up every opening in
the transom to prevent further moisture from getting in. Slop as much
waterproof paint or sealer as you can into all mounting holes and let
it dry before reinstalling the hardware. If you have an aluminum transom
cap, a 4" wide strip of well saturated fiberglass followed with a coat
of brushed on epoxy paint should do a nice job of sealing the top of the
transom, then re-install the cap. Look around for any other places that
moisture may be getting in, like gelcoat cracks and inside the base of
the transom and seal them with the appropriate material.

The only real expense here is time. If it doesn't work you can resort
to more expensive & extensive measures next year. If it doesn't work
you didn't hear it here.   8^)

Rick W.

    John,
    
    I have a problem with a fiberglass covered floor. Moisture got into
    the wood from below and rotted it out. I'm told to get everything
    dry, cut out the rotted part and apply "Get-Rot" to the rest of
    the wood I can reach.
    
    I havn't done anything yet, but it sounds like the "Get-Rot" is
    some sort of super sealer or drying agent. You might want to check
    a local boat yard for info.
    
    As soon as I find out (a couple of weeks, I hope) I'll let you know.
    
    Don

    HAving restored MANY old wood boats Ive used a good deal of Git-Rot.
    Basically my opinion is its a fully useless product, but you always
    hope it will work. Ive never seen it work.
    
    Its a very thin epoxy, the theory is it will soak into all the rotted
    wood, then harden. The displays in the store used to show a plastic
    screwdriver handle as an example of its final hardness. 
    
    The problem comes in two areas- the wet wood doesnt let the epoxy
    saturate, for which the directions state you should use acetone
    to drive out all moisture. Secondly, the stuff will soak fairly
    well into the rot, since its much like a sponge, but then it stops
    soaking somewhere in a region thats about half-rot, half good. The
    rot simply continues in that region and next year you have a nice
    hard block of epoxyed rot,surrounded by more new rot.
    
    I have used it several times, always wound up doing the job right
    and replacing the wood the next season.
    
    As a side note, Git-rot is a trade name, invented by a friend of
    mine,Platt Monfort. The patent expired last year, and there are now several
    similar products on the market. Platt is currently pushing his
    'Geodesic Ultralight' boats. A 12' canoe weighs about 10 lbs! Platt
    is a NEAT fellow, the stereotype of the wacky inventor.

Wet wood is much less strong (or at least much less stiff) than dry wood. 
Rotted wood has no strength at all. Marine plywood uses boilig 
waterproof glue and has (supposedly) no interior voids. It will still 
rot. It is most unlikely that the soggy plywood in your transom will 
ever dry out through the hardware mounting holes alone. The only way to 
really fix the problem is to cut out one face of transom, remove all the 
wet plywood, bond in new plywood, and laminate a new fiberglass skin. 
Time consuming and messy, but not all that difficult. There are places 
that do this type of work (eg, David L Shepard, Inc in Newburyport -- I 
don't know if the company is still in business). 

                   <Reply to 49.3 requesting more info>
                                            
    This 12' canoe and it's inventor both sound interesting. Can you
    provide any more information on the canoe and how to get in touch
    with it's inventor? This type of canoe sound just like what I've
    been looking for.
                            Robin

    The canoe is one of a series of boats Platt has designed, all built
    by a technique he calls Geodesic. Essentially he sets up a frame
    of very thin wood, almost like kite sticks, which is all wrapped
    in kevlar, then covered with Heat Shrink Aircraft Dacron. The result
    is a very light, but also very strong boat. The construction jig
    is ordinary cardboard boxes. All VERY clever.
    
    Platt sells a variety of plans and kits for canoes, rowboats and
    sailboats. For $1 he will send a nice package of brochures. 
    
    Monfort Associates
    RFD 2 Box 1490
    Wiscasset ME, 04578
    
    Tell him where you heard about this!

    The info I had was get rid of the rotten wood, dry everything out,
    then apply the Git-Rot. With the rot gone and everything dry, it
    seems like it should work. Comments????
    
    Don

    re .7, my question would be what's the git-rot supposed to accomplish?
           all it is is thin epoxy, I think.  Also, the fungi that go
    after wood, as I remember, extend filaments out into surrounding
    wood; getting rid of visible soft and punky stuff may not stop the
    process.  
    

    RE.8,  Thats my question also---ahat stops it? Sounds like "Git-Rot"
    is a hoax!!!
    Anyone know what DOES stop it from spreading??

    An article I came across about dry rot stated that bleach was
    effective; they were talking about places where you could apply
    repeated applications, though.  I don't know if bleach is compatible
    with fiberglass or glues, either.

    Having built and re-built wooden boats for more than 20 years Ive
    become something of a rot expert :-)
    
    Rot is a fungus. As a living thing it needs food, air and water.
    You stop it by depriving it of any of these things.
    
    For food it eats the wood, so we cant eliminate the food source,
    but we can poison it. Thats what things like Cuprinol and a whole
    lot of very noxious chemicals try to do. If they are well applied
    they will in fact poison off the rot spores.
    
    Dry rot is really a misnomer, because rot must be wet to surrive.
    If we could keep the wood really dry it cant rot. Since thats not
    possible in boats the other altenative is to make the water to salty
    for the rot to live in. Dry rot always starts where fresh water
    accumulates, mostly form rain. Old schooners actually packed the
    bilges with rock salt to keep the wood from rotting. Forget about
    paint and varnish as a 'sealer' to keep the water out of the wood.
    No paint seals wood to any appreciable extent. Some epoxy products
    claim to seal wood totally, but even these are exagerated claims.
    
    Like sealing out water, sealing out the air is also not likely to
    work. 
    
    Git-rot isnt quite a fraud, but it doesnt really work very well.
    You are NOT supposed to remove the old rotted wood, its supposed
    to remain in place to be a 'wick' to absorb the rot and fill whatever
    gap that piece of wood was filling.
    
    The only solution to rot is TOTAL SURGERY. Remove ALL traces of
    the effected wood and replace it with new. Treat the new with
    preservitive and then handle the boat properly, fix fresh water
    leaks before they become a problem, keep the boat clean, etc.

    I had the same problem on a 15' Larson 20 year old fiberglass boat.
    I elected the surgery route. I ripped out all the old floor, cross
    braces, lateral braces, and side braces. I replaced all wood with
    treated marine wood, sealed it all with bondo (fiberglass resin
    compound) to the existing hull and coved it with all weather
    carpet. It was definitely NO fun. I certainly would NOT do it
    again. It cost me about $200 in material and about $20000 in labor.
    It's not worth it. Save your money and get a new boat and take
    care of it so leaks don't ruin your boat.

    Does anybody have any first hand experience with using salt water
    in a wooden boat to discourage rot?  I have a 17 foot cedar hulled
    ex salt water boat with no hull rot.  When I pull the boat onto a
    trailer between LAKE trips I put about 2 gallons of Halite (rock
    salt) laced water into the boat to keep it swollen up and rot free.
    Anybody tried this?  How is it that a medium such as sea water which
    has a tremendous number of living organisms in it can't support wood
    rot?  I have heard it said that salt water wooden boats don't rot
    below the water line (I didn't say worms such as toredo didn't eat
    them), and rot in a wooden salt water boat tends to be in the decks
    where rain hits.
    
    Jeff

    Jeff, I've been intently reading everything that I could find regarding
    wooden boats since I bought my Century four years ago.  I've never
    seen any recomendation to use salt water to prevent hull rot.  It's
    always "open all hatches, access doors, and remove seat cushions.
    Insure adequate ventilation to prevent moisture accumulation", etc.
    I would suggest you give Boyd Meffard a call at Boyd's Boats in
    Conecticut (203-693-4811).  Boyd deals in nothing but wood runabouts
    from totally restored to complete basket cases.  He loves to talk
    and is a wealth of information.  If he has an opinion on the subject,
    he will let you know it.  Please post what you find out.  I'm
    interested in this theory of yours.  Of course my boat wouldn't hold
    the salt water in long enough to do any good anyways.
    Wayne

Salt in the bilges will keep a wooden boat from rotting, at least where 
the briny water contacts the wood. (Excessively salty water kills most 
everything.) The wooden fishing schooners preserved the fish in their
holds with salt (and preserved their hulls at the same time, which is
one reason there are a few left). Lots of ventilation and keeping the
interior dry is also an excellent idea. 

    
    	I noticed a small area on one of my Nautique's stringers where
    the fiberglass has either deteriorated or was never there to begin
    with. The later is unlikely, since it's a Correct Craft :-)
    
    	I plan to patch it with fiberglass this weekend. Any suggestions
    on inspection of the stringer prior to patching other than looking
    for obvious rot?.
    
    	Thanks,
    
    	Rick

    
    >>	I noticed a small area on one of my Nautique's stringers where
    
    	Before anyone else zaps me on this.... No I don't own more
    than one Nautique and yes the one I own has more than one stringer! :-)
    
    Think Spring!
    
    Rick
    
    

Best thing I can recommend it to check every bolt/screw that attaches something
to the stringer and see if it's still good and tight.  By this I mean try to
wiggle the bolt/screw (or what it's attached to), don't back it out.  If it
seems solid, *LEAVE IT ALONE*!  It's definitely a "if it don't look/feel
suspicious, don't f%#k with it!" situation.

I'll show you what my stringer looks like when you come to the Indoor Gumball
next week.  If you wanna wait till then, you might get some ideas on what to
look for.

...Roger...

    A stringer is an extremely important part of the hull. Therefore
    if i were you i'd go ahead with the inspection process.
    
    You can do this simply. Using a mallet with a plastic face,
    tap the area where the glass is missing, move along the stringer
    until the tone changes. Your looking for a consistent sound,
    (a solid sound) this will tell you how much (if any of the plywood)
    is wet, rotted, or whatever.
    
    Once you figure out how much damage there is, we can talk
    more about fixing it.
    
    I hope i explained the use of the mallet so its understandable.
    
    If the boat is stored inside, and the area is above 50 deg. F
    you probably could go ahead with repairs, check the container
    for minimum temperatures...
    
    JIm.
    

    
    	Repair update time...
    
    	The removable floor, back seat and gas tank are now
    out of the Nautique. The flaw in the fiberglass appears
    to have been caused by two different materials not bonding
    together very well.
    
    	There are 4 stringers in the boat. One on either side of the engine
    running the length of the boat and a pair about 8 inches from those
    running about � the aft length of the boat. The two mufflers are housed
    in the cavities created both port and starboard. Poor graphics follow:
    
    				       /\
    				      /  \
    				     /|  |\
    				    / |  | \
    				   /  |  |  \
    				  /   |  |   \
    				 |    |  |    |
    				 |    |  |    |
    				 |    |En|    |
    				 |    |gi|    |
    				 |   /|ne|\   |
    				 |  | |  | |  |
    				 |  | |  | |  |
    				 |  | |  | |  |
    				 |  | |  | |  |
    				 |  | |  | |  |
    				 |  1 2  3 4  |
    				 --------------
    
    	Near the top (but on the inboard side) of stringer #1 the
    fiberglass has separated from the wood stringer, in varying
    degrees for about 12-15 inches. The area between
    stringer #1 and the chine is foam filled. It appears as if the foam,
    which is installed after the last covering of glass did not agree
    with the glass. The foam extends a small thickness of itself over the
    top of stringer #1. 
    
    	I seem to have several alternatives in this repair ranging in
    complexity.
    
    	1) Cleanup the area and re-glass only the *side* of the stringer
    
    	2) Remove as much foam from the top of the stringer as possible
    		without removing the floor and attempt to re-glass 
    		not only the side of the stringer, but also the top of it.
    
    	3) Remove floor and foam and re-glass both sides and the top of
    		stringer #1.
    
    	I'm leaning toward solution #2... any comments?
    
    	Thanks,
    
    	Rick
    

    I tend to agree with you. I'll take a guess that the foam might
    not agree with the resing you apply, i.e. melt it.
    
    I would recommend you DO NOT use polyester resin, it does NOT
    bond to wood very well.
    
    JIm.

    RE: .21
    
    Right.  Epoxy resin would be better for this repair job than 
    polyester.  Last week BOAT/US had Epoxy on sale for $24.98/
    gallon, about $3 cheaper than the "less expensive" polyester.
    
    You ARE a member, right Rick?    8^)
    
    Rick

re                        <<< Note 49.20 by KAHALA::SUTER >>>
>                       -< Glass and Foam, do they mix? >-

    
>    	Repair update time...
    
    
>    	Near the top (but on the inboard side) of stringer #1 the
>    fiberglass has separated from the wood stringer, in varying
>    degrees for about 12-15 inches. The area between
>    stringer #1 and the chine is foam filled. It appears as if the foam,
>    which is installed after the last covering of glass did not agree
>    with the glass. The foam extends a small thickness of itself over the
>    top of stringer #1. 

	Does this coincide with the trailer bunk ?   Might this be 
where/why it gets such a beating ?

>    	I seem to have several alternatives in this repair ranging in
>    complexity.

	4)	Call CC

>    	I'm leaning toward solution #2... any comments?

	Try #4, they're   REALLY VERY GOOD !    

>    	Thanks,
 
	Y'Welcome
   
>    	Rick
    

	Reg

>	Does this coincide with the trailer bunk ?   Might this be 
>where/why it gets such a beating ?

    	Could be... but why wouldn't the other side have done the same
    thing?
    
>>    	I seem to have several alternatives in this repair ranging in
>>    complexity.

>	4)	Call CC

>>    	I'm leaning toward solution #2... any comments?

>	Try #4, they're   REALLY VERY GOOD !    
    
    	Well, I took suggestion #4 and the word from CC is Polyester
    resin... Hmmmm... Also, he seemed to think the FG might not have
    been actually ready for the foam either, although he'd never seen
    it before in such a young boat.
    
    	Speaking of a young boat.... he did mention that the AME4000 is
    several times stronger than the material my boat is made from. 
    Hmmmmmm..... 1991? :-)
    
    Rick

    
    	Well, the stringer is all glassed back in. I ended up
    doing a section about 6" by 24" when all was said and done.
    
    	Boy fiberglass is brutal stuff to work with. It hardens
    before you expect it and generally makes a sticky mess. Polyester
    resin is on sale though, at Bliss for 14.xx a gallon.
    
    	Now I need more ideas... What type of white paint should
    I use in the bilge over the new and old glass? should I really
    be daring and paint the entire bilge, taking care not to stick
    up (or down) my auto bilge pump switch :-)
    
    Rick
    
    And, yes I shed a tear or two with those 70+ temps yesterday
    and no prop! I did however spot 2 jetskis on the river.....
                 

    get a 2 part epoxy type paint, mix in a little "tints all"
    
    its a coloring agent to make the new paint job blen in.
    
    by all means, IMHO don't paint the whole bilge, at least it
    
    would make me suspicious, if it were for sale..
    
    p.s. the epoxy paint is less likely to peel..
    
    
    JIm.

    I have a rot hole in the floor of a 16.5 glastron fiberglass boat that
    needs to be repaired.  The hole is aprox. 6" X 6".  It will grow to
    aprox. 12" X 12" after all the rot is cut out.
    
    I assume that the material of choice would be marine plywood screwed
    down and then covered with fiberglass to fix this hole.  Has anyone
    ever thought of using or has used pressure treated plywood?  The only
    concern that I can think of is, would fiberglass adhere to it?
    
    Thanks,
    
    Wayne

Fiberglass sure does adhere to pt wood.  I installed a new stringer beam in my
boat this year, a "modified" 2"x8"x14' chunk of wood, then glassed it in.  The
cloth and resin stuck quite nicely.

I replaced my floorboards this year with pt plywood (1/2" thick, one side
sanded), and have a couple of small pieces left over.  I probably have a 12"x12"
piece if you want it (are you located in the vicinity of the Mill in Maynard?).
Better than paying $20+ for a 4'x8' sheet and using 1/32 of it!

Let me know.

...Roger...

    Wayne,
    I think you're right, not much will stick to pressure treated
    when it's fresh.
    
    Since you want to glass it in anyway, try using West System
    encapsulating epoxy.  It will work to both glass it in and 
    make it waterproof.  You'd probably want to give the underside
    of the wood a coat or two of resin before installing it to
    fully waterproof it.
    
    West System products are available from some of the mail order
    catalogs.  Wilderness Marine in Amherst NH also carries it, and 
    is about 1/2 hour from where you are in Leominster.  Take route 
    13 north to 101 east, then take your first exit onto 101-A east 
    and you're there.
    
    Rick

    I just saw Roger's reply which beat mine by a few minutes and
    says glass *will* stick to p.t. plywood.  Oh well...  I know
    they say not to paint or stain p.t. for a year, figured fiber-
    glass would be the same.
    
    Since Rog has some extra scraps of p.t. maybe that's the way
    to go.  When the rest of the boat's history that piece of 
    floor will still be there!    8^)
    
    Rick

    Thanks for the quick replies.  Roger, thanks for the offer, but I do
    have a need for more than the 12" x 12" piece.
    
    Thanks again,
    
    Wayne

    I guess I was dreaming about a 12" x 12" hole.  I now have .75 of the
    floor cut up.  I have a few questions about things I came across.  My
    boating terminology is not up to par so please bear with me and feel
    free to correct/comment.
    
    Running down the center of the boat is a beam.  Stuffed on both sides of the
    beam is styrofoam.  My question is what is it for and do I need to put
    it back.  Most of it is water logged and will most likely take decades
    to dry out.
    
    When I was cutting out the floor, most of which is in the back, I
    noticed that the only place it was anchored was on the center beam. 
    There are two other beams, one on each side of the center, that did not
    appear to have any nails/stapples in it.  Is that the norm?  I assume
    by only anchoring the floor down the middle and glassing over the floor
    would allow for flexing of the boat.  Am I on track here?
    
    Thanks,
    
    Wayne

RE: .32
    
>> Running down the center of the boat is a beam. 

This is the keel.  It is the beam around which all of the other gridwork
or stiffeners are attached.  It must be in good condition, or the hull
can flex, twist, crack, etc. while the boat is underway.

>> Stuffed on both sides of the beam is styrofoam.  My question is what 
>> is it for and do I need to put it back.  

It is used for several purposes.  It provides positive flotation (well, it
did before it got waterlogged...).  If it is still bonded to the hull it 
helps to stiffen it.  And it provides noise dampening.  I'd remove what's 
there, clean the floor and let it dry thoroughly, then replace it with some
of the closed cell spray-in stuff.

>> There are two other beams, one on each side of the center, that did not
>> appear to have any nails/stapples in it.  Is that the norm?  I assume
>> by only anchoring the floor down the middle and glassing over the floor
>> would allow for flexing of the boat.  Am I on track here?
   
The other two beams are called stringers, and are part of the gridwork which
helps to stiffen the hull.  The entire gridwork is fastened together, and
when boxed in by the floorboards creates a very stiff assembly which helps
to prevent the hull from flexing.  As you can imagine, a fiberglass hull by
itself with no support is very flexible.  I'm surprised the floor was not 
attached to the other stringers, because the more you can box it in the 
stiffer the assembly will be.  Fastening the floor to all of the stringers
should also help prevent the floor from warping and feeling "springy". I'd 
fasten the new floorboards to all of the stringers, not just the center one.

Rick

    Thanks for the explaination Rick.  Where does one get this spray in
    foam?  Is it a hardware item?  Is it a marina item?  Is it big bucks? 
    How much do I spray in?  Just enough to cover the beams and hull, or
    fill from the hull to the floor?
    
    Thanks,
    
    Wayne

re  foam floatation, coupla points;


i)	I'd try to put as much of the floatation as high as possible,
	i.e. under gunnels, fore-deck, and any other high horizontal
	surfaces.  If the boat gets swamped the worst thing is to have 
	it also flip over - well, one of the worst things.

ii)	I would avoid putting foam where it has proved to trap water
	and encourage rot - I wouldn't want the same problem again in 
	a few years.


FYI, FWIW, IMHO, JBTW, etc.

Wayne,

The spray foam is available from most marine supply stores.  I believe
it's different from the insulating foam spray which is available in hardware
stores.  You want the closed cell foam so it doesn't absorb (as much) 
water.  You'll have to experiment to find how much to spray in, and allow
room for the foam to expand.

Reg raised a good point; leaving space for drainage.  Try to leave troughs
or channels near the stringers for water to flow toward the stern and out
the drain plug.  If the existing stringers and supports don't have drain
holes near the floor to allow water to flow through them, then cut or drill
some before you close it up.

Here's one way to make sure you have permanent drain channels through the 
foam and the stringers.  Go over to Spag's, and buy a whole bunch of those 
plastic tubes that go inside of a golf bag to separate the clubs (small PVC
pipe would also work).  Drill a s#!tload of holes in them, and place them on
the floor running fore and aft, all the way to the bilge drain, then spray
the foam in, trying not to block up the holes you drilled.  It should work
kind of like a leaching system, only reversed.

Rick

    
    
    You could also go to Grossman's or Somerville Lumber and pick up some
    of the white plastic drainpipe that already has the holes-
    
    
    In my Boat (22' North American) the drains are all 3/4" black PVC
    All the compartments drain into the engine compartment where the Bilge
    pump is located.
    

    Can anyone recommend the best type of wood to use when replacing
    the keel and stringers, and how to prepare the wood before attaching
    to the hull?   
    
    Also, does the fiberglass hull have to be sanded clean before glassing
    and matting the keel, stringers and trusses in place?
    
    I also have to replace quite a few feet of floatation.  Is closed cell
    spray in foam the most economical and efficient material, or could I
    use 2" sheets of foam insulation?
    
    Finally, which type of plywood is best for the floor?  I was quoted
    $80.00 for a 4' X 8' sheet of marine plywood.  Is pressure treated or
    outdoor grade plywood durable if sealed with fiberglass mat?
    
    Thanks for the help.  Funny how big a project can get when it comes to
    rot....    this would be fun if it weren't so itchy!
    
    Regards,   Henry         GOLF::HWALSH

    Yes, exterior plywood is o.k. - It is identical to marine plywood,
    except that the inner plies will have some voids in exterior, where
    marine will not. They use the same glue and are otherwise identical,
    except for the very large difference in price.
    
    Bill
    

    Moved by moderator.
    
================================================================================
Note 1052.0                      Replacing wood                       No replies
GOLF::HWALSH                                         25 lines  21-APR-1993 12:40
--------------------------------------------------------------------------------
    I am in the process of replacing the keel, stringers, spars,
    deck and flotation on a 1968 Glastron 18 - 19' with an I/O.
    To me, it's a classic, and I don't mind doing the work,
    (although it is hot, itchy work at times...)
    
    Could anyone provide advice  as to what kind of wood to use
    and what works best to seal the wood before installing to the hull?
    Spar varnish, polyster resin or ????
    
    Is 3/4" red oak adequate replacement for the keel and stringers?
    Is marine plywood required for the spars and deck?
     
    Can pressure treated, or exterior plywood be sealed and remain
    durable for use on the floor and spars?
    
    What is the best way to prepare the fiberglass hull to accept
    the ppolyester resin and mat, when attaching the wood?
    
    And finally, is there an inexpensive closed cell foam for use
    when replacing floatation?
    
    Thanks in advance for the advice.  I hope to do this project only once
    in my lifetime!
    
    Henry            

	If you wanted to totally seal the stringers you could use
	a type of Epoxy (not polyester resin), the same that's used
	with fiberglass mats.  I'm no expert on epoxy and fiberglass,
	but I was told not to waste my time using the quart of polyester
	resin I have, and to use the System 3 exclusively.  I've been 
	using the System 3 Epoxy with great success in rebuilding my 
	'58 17 ft Thompson (all wood). 	
	
	I get it delivered from a company in Springfield.  When you buy 
	this stuff you get a book on how to use it for boat construction 
	and repair, wooden and fiberglass.  Epoxy coating is one usage 
	described to seal wood and keep it dry, to prevent warping, etc.
	If your stringers are constantly submerged, you might want to 
	consider epoxy coating.  Otherwise it might be overkill.
	
	My boat has 3 stringers, a large one that's about 1.5 inches
	thick, and 2 more to the sides.  They all oak.  I'd probably use 
	a hardwood like oak for your stringers.  I paid $5.00 a sq foot
	for 7/8 oak for other parts of the boat - it's not cheap!

>    Can pressure treated, or exterior plywood be sealed and remain
>    durable for use on the floor and spars?

	The following comes from the epoxy book I have:

	"It is not necessary to use marine grade plywood in boatbuilding.
	Marine plywood is basically exterior plywood wiht a lower void
	content. Several years ago the plywood association that sets 
	specifications started degrading marine plywood by allowing a 
	higher void content. We beleive that the extra cost for fir marine
	plywood over A-B exterior is not justified today"
    
	I'm using exterior grade plywood to replace the floor on my boat.
	I'm just using a wood preservative/stain on it.  A more expensive
	longer lasting option is to epoxy coat it w/ fiberglass mat, but 
	to me it's no big deal to replace it in a few years if it softens 
	up.  The floor I'm replacing was regular plywood and it lasted
	for years.

	Ken

    Thanks for the info Ken.   Good luck rebuilding the 58 Thompson!
    
    I will seal the 3/4" X 5" X 8' oak stringers 
    (your right not cheap even at $2.15/ft.!), with epoxy, and cover
    the floor with exterior grade plywood covered with epoxy and 
    fiberglass mat.   ## I noticed last pm that the oak I bought is
    bowed....
    
    
    
    Would anyone know where to get the System 3 epoxy or equivilent?
    
    Any advice on floatation too?
    
    Henry      rebuilder of the 68 Glastron 
                
    

    Henry,
    A few comments on your project...
    
    While epoxy is definitely the way to go as far as strength and
    durability, it's also going to cost you a LOT more money. You
    may want to evaluate how long you'll keep the boat, and how you'll
    use it.  Very few production boats are built with epoxy in the 
    first place, they all use polyester resin, and in most applications
    it lasts a good long time.
    
    System 3 and West System expoxies are available through several
    of the marine mail order catalogs.  Ken Hannon also says he has
    a good source in Springfield.
    
    As mentioned, marine plywood is overkill and too expensive. Standard
    plywood is waterproof.  The only problem you may run into is that
    if you're fastening the wood in the area of a void, it may compress 
    a little on you.
    
    Spray cans of foam flotation material are also available through
    some mail order houses.  Some local marinas carry it too I s'poze, 
    but you don't see it often.  
    
    Pressure treated wood will work for stringers and flooring. But
    it's more than twice (probably 3 or 4 times!) as heavy as kiln
    dried wood.  Something to consider if you're replacing a lot of
    wood.  Also, I wonder how well the polyester or epoxy resin will
    stick to it, considering how moist P.T. is.  I know that Bass 
    Tracker and Nitro are using P.T. plywood for their floors, but 
    they're not sticking any resin to it.
    
    You asked about cleaning the existing glass before applying new
    resin.  In the bilge area, not only should it be well scuffed,
    but it should also be thoroughly de-greased.  Bilge water tends
    to have an oily film.  Clean it with acetone, lacquer thinner,
    brake cleaner, or a similar solvent.
    
    Good luck!
    Rick

    Thanks for the tips Rick.   It's true, I want to be practical too
    when selecting materials.  I'll need to find out how much the
    epoxy costs vs. polyester resin and make a decision based on the
    value and life of the boat.
    
    Sounds like exterior grade plywood is sufficient too for the floor
    and spars.   And that pressure treated is not required and heavy.
    
    I may seal the stringers with epoxy and epoxy the stringers
    and fiberglass mat to the hull, and let that cure.
    Then cover the exterior grade plywood with polyester resin   
    and fiberglass mat, and let that cure.  Then screw the plywood
    to the stringers and plywood cross members.   Would that procedure
    raise compatibility issues?
    
    I have a cleaner for the inner hull and bilge area, but am not
    looking forward to sanding the fiberglass!
    
    I'll have to find the spray in foam floatation.  If the spray in 
    foam is used, does it adhere to the stringers and hull, making 
    future repairs a little more difficult?  Is replacement floatation
    available in 2" X 4" runs? 
    
    But I like the idea of using tubes, as mentioned earlier in this topic,
    to create a water channel thru the floatation.
    I think that poor drainage thru the stringers caused the waterlogged
    stringers and floatation in my boat. 
    
    Any additional advice/pointers are appreciated!
    
    Henry 
    

Spray foam, either one part or the better two part stuff, adheres to 
almost everything with great tenacity. Removing it once cured is very 
difficult. 

Cheap foam, like stryofoam blocks, absorbs water over time and probably 
should not be used. 

There has been considerable discussion in WoodenBoat and BoatBuilder 
magazines regarding the merits of marine plywood. One of the big 
disadvantages of fir exterior plywood is that getting a smooth finish 
after coating with either epoxy or polyester resin is so time consuming 
that it is cheaper for professional boatbuilders to use marine plywood. 

I've used both polyester and epoxy resin. I find epoxy vastly easier and 
more pleasant to work with. No solvents are released during curing, for 
one thing. System 3 is very good stuff. 

Oh yes, red oak is not considered to be rot resistant. If you use it, 
I'd recommend coating it with three or so coats of epoxy to essentially 
waterproof it.

Alan

	re: -.1	 red oak is not rot resistant

	That's for sure... and neither is mahogany, as I found out 
	with the Thompson.    The carpenter ants *loved* the mahogany
	transom too, living a life of luxury till I tore it apart ;-)

	re: System 3 epoxy and the stringers/fiberglass

	I've been dealing with Merton's Fiberglass out of Springfield
	at 413-736-0348 or 800-333-0314 (for placing orders).  The guy
	who runs the place is very helpful, and should have good input
 	with the issues you have.   For epoxy coating the stringers,
	I don't think you'll need all that much.  Working with fiberglass
	mat and the epoxy resin is a lot easier than I thought it would be,
	even for overhead applications.  A 1.5 quart unit is about $25.00 
	and should coat quite a bit.  

	Ken

    Ken, thanks for the pointer...
    
    I checked with Dave Merton at Merton's Fiberglass, a very
    knowledgeable, patient and helpful fellow.
    
    Dave provided some more info;
    
    * It's common practice to use construction grade spruce or fir 
      for the stringers, since it is the polyester resin and matting
      that provide the strength/protection. Epoxy is nice stuff for glass like
       finishes on wooden boats, but not recommended for the fiberglass 
       hull.  
    
    * Grind or rough sand the fiberglass hull and vacuum.
    
    * Round the top edges of the stringers so the fiberglass mat will
      drape over easily when attaching to the hull.   Also, fiberglass
      a piece of fir wood on top of the stringers running the length of
      the stringers to provide a wider base for attaching your deck.
    
    * Use yellow pine exterior grade plywood and polyester resin coat the
      bottom and put a layer of matting and  1 - 2 coats of polyester resin.
      (Fastened first with stainless steel fasteners)
    
    Joe recommended that I put in access hatches which can be removed to
    ventilate the hull area during storage or as needed.
    
    Mertons's sells closed cell foam w 2 parts  Gallon A & Gallon B 
    makes about a 55 gallon drum full for $60.00
    
    Looks like it's time to get the materials and get started.
    
    Thanks for all of the info.   
    
    Henry