Re: latex house paint
I absolutely agree with Jeff. For a boat not sitting on a mooring, a
paint job, maintained every couple of years is fine. Epoxy without
glass is theoretically fine, but in practice you cannot maintain the
perfect barrier to moisture it requires....wood will move or the
surface of ply will check, damage will happen and it is a continuous
round of maintenance. I sanded down my 30ft trimaran, epoxy coated
it, then paint. Frankly, the epoxy without glass was a waste of
money. For a boat for life, epoxy/glass is best. It's up to you to
decide the level of cost and protection most appropriate for you.
DonB
paint job, maintained every couple of years is fine. Epoxy without
glass is theoretically fine, but in practice you cannot maintain the
perfect barrier to moisture it requires....wood will move or the
surface of ply will check, damage will happen and it is a continuous
round of maintenance. I sanded down my 30ft trimaran, epoxy coated
it, then paint. Frankly, the epoxy without glass was a waste of
money. For a boat for life, epoxy/glass is best. It's up to you to
decide the level of cost and protection most appropriate for you.
DonB
--- In bolger@y..., Richard <rocwandrer@p...> wrote:
> before i asked this question i look around a house paint oriented
sites, at boat paint sites Dave
> Carnell's site (very good write-up) etc. etc. I didn't feel
confident using any old 100% acrylic latex
> house paint until i had more info from other people with hands on
experience. I have gotten a number
> of replies to my query and every single one of them has been
helpful!!!!!
>
> Thank you everyone!!!
>
> Ok, so i have more questions :-) it seems to me that glassing the
outside of a boat that is strong
> enough, will not benefit me anything in additional strength. I
fail to see how having epoxy inside of
> fiberglass strands makes a boat more waterproof that having
epoxy "painted" onto the outside of the
> boat. I am not saying it doesn't, i am asking why it does if it
does.
>
> my boat will be in the water less than 12 hours at a time. it will
be in indoor storage for not less
> than 90% of its life.
>
> I hate fiberglass. i never seem to do it right. should i
>
> 1 primer and paint the boat with latex porch paint.
>
> i have been told that glassing the boat is needed for a good
service life. i don't mind touch up and
> dave carnell states that epoxy coating without glassing is a waste
of money. he doesn't say why. it
> would seem to me that if epoxy is a greater water barrier (can that
be implied from the fact that it is
> a greater vapor barrier?) than it is like a better paint job.
>
> 2 "paint" the boat with epoxy (x coats?) and sand and primer and
paint with porch paint.
>
> many plans providers that also sell epoxy seem to recommend this
approach, in addition to glassing....
> hmm
>
> 3 glass the boat with epoxy and sand and primer and paint.
>
>
> thanks again,
> Richard
>
>
>
> Message: 15
> Date: Thu, 23 Aug 2001 00:36:35 -0000
> From: dcraig@w...
> Subject: Re: latex paints
>
> Richard, I would suggest going to Dave Carnell's Boat Building
Page
> and reading his article on Latex Paints For Boats - I would give him
> some credence since he is a chemical engineer.
>
> > i have a quick (i hope) question about latex house paints. I have
> been reading some propaganda
> > (advertisements) that talk about letting the wood "breath." i
know
> that proper moisture content wood
> > should not need to "breath", but does this mean that latex house
> paint is formulated to be porous?
>
> That's pretty much exactly what it means. In an earlier life, I
was
> making carved wooden signs for a living and I did NOT want paint
> blistering. These signs were going to be exposed to sun and
elements
> 24-7-365, year after year. I researched the literature from
> experienced sign makers and learned that the best protective coating
> was not oil paint but latex. Oil paint had the best reputation
> because it had been used for centuries - it was all that was
> available, not counting shellac and lacquer, milk paint etc. - and
> latex was new and crappy at first, but excellent today.
> The proper moisture content of wood is not worth bothering about,
> for our purposes, because kiln dried values are worthless as soon as
> you stack the wood in an open air warehouse - and that's where most
of
> us find our stuff.
> All wood, seasoned or not, has moisture in it to a greater or
> lesser degree. Depending on the moisture content inside the wood
and
> the outside climatic conditions, oil paint can be a great coating
for
> many years or it can start to blister in a few years. The reason
for
> blistering is that the moisture wants out and the oil paint won't
let
> it out, so the wood and paint separate. Oil paint is not porous for
> the passage of moisture.
> I recently scraped and repainted a fancy fence that had been
> painted with oil six years ago. In places the paint pulled off in
> strips. Underneath, the wood was green with fungus and wet; wet,
even
> after five weeks of hot dry weather. There was nothing wrong with
the
> paint, it was thick and the strips were strong - but there was a
> failure in the bond between paint and wood.
> Latex paint, in my humble opinion based on research (reading) and
> experimentation, is porous to the passage of moisture and will not
> blister (that doesn't mean it won't strip off epoxy that has not
been
> properly prepared). The best paint I found for signage was Pratt &
> Lambert exterior acrylic/latex house trim paint. It has a high
level
> of pigment content, so color retention lasts longer under weather.
> Signs I painted six years ago with acrylic/latex have still not
> blistered.
> Honestly, I do not know, or have an opinion, on how latex would
> perform on the bottom of a boat that sits in the water all season.
But
> for a dry sailer, I would use it.
>
> how
> > do i tell an intentionally porous latex house paint from a good
one
> for a boat.
>
> For a boat, I would consider an acrylic/latex 'deck and porch'
> enamel - paint that is intended to be walked on should be the most
> durable.
> I've had this discussion with so-called house painters who do
this
> for a living, and I hear things like 'latex paints on a fence or
sign
> are good, but you still have to prime it with an oil base primer.'
Go
> figure.
>
> Don Craig
> --
> To invent, you need a good imagination and a pile of junk. --Thomas
Edison
My Nymph uses 1 oz glass. No checking so far, but it's only been
outside a few months, and it may not be a fair test since it may be a
type of plywood that doesn't check. I think well painted luan may not
check, but there can be other problems if it's cheap stuff, like
delamination. And if it gets damp for a long time, I think it will
check anyway.
outside a few months, and it may not be a fair test since it may be a
type of plywood that doesn't check. I think well painted luan may not
check, but there can be other problems if it's cheap stuff, like
delamination. And if it gets damp for a long time, I think it will
check anyway.
--- In bolger@y..., David Ryan <david@c...> wrote:
>
> >Glassing and epoxy eliminate for the most part the tendency for
plywood to
> >check.
> >
> >In a nutshell, I myself would not use just epoxy. It would be
either none,
> >or used with glass.
>
> In my experience with paint only, epoxy "sealing" and paint, or
> epoxy, glass and paint; I'd say that either go cheap with paint only
> or go big with epoxy, glass and paint.
>
> Don't waste your time and money going epoxy only. It'll check just
as
> bad as paint alone.
>
> BTW: You don't need heavy glass to prevent checking. I've got 3.6
oz
> still looking good after 12 continuous months of being outside.
>
> YIBB,
>
> David
>
>
>
> CRUMBLING EMPIRE PRODUCTIONS
> 134 West 26th St. 12th Floor
> New York, New York 10001
>http://www.crumblingempire.com
> (212) 247-0296
My two bits...
A quick coating of epoxy, without glass, doesn't add to strength or do much
for checking, but it does provide a nice surface for painting. I do this
with cheaper (rough) plywood -- it fills holes and flaws that paint doesn't.
If its real cheap plywood, like the leeboard and rudder I'm currently doing
for the elegant punt, I thicken the epoxy slightly and use a squeegee. It
only took about 6 ounces of resin/hardener plus some thickener for both
pieces.
Checking is not always a big problem. The elegant punt itself has only oil
paint over the bare plywood (no epoxy), is 5 years old, was repainted once
(last year) and hasn't a check on it. Its stored on the shady side of the
house, propped up so the rain can't pool in it.
Jamie Orr
PS If you epoxy, be sure to wash it well once cured and sand before
painting.
-----Original Message-----
From:cha62759@...[mailto:cha62759@...]
Sent: August 23, 2001 12:59 PM
To:bolger@yahoogroups.com
Subject: [bolger] Re: latex house paint
A quick coating of epoxy, without glass, doesn't add to strength or do much
for checking, but it does provide a nice surface for painting. I do this
with cheaper (rough) plywood -- it fills holes and flaws that paint doesn't.
If its real cheap plywood, like the leeboard and rudder I'm currently doing
for the elegant punt, I thicken the epoxy slightly and use a squeegee. It
only took about 6 ounces of resin/hardener plus some thickener for both
pieces.
Checking is not always a big problem. The elegant punt itself has only oil
paint over the bare plywood (no epoxy), is 5 years old, was repainted once
(last year) and hasn't a check on it. Its stored on the shady side of the
house, propped up so the rain can't pool in it.
Jamie Orr
PS If you epoxy, be sure to wash it well once cured and sand before
painting.
-----Original Message-----
From:cha62759@...[mailto:cha62759@...]
Sent: August 23, 2001 12:59 PM
To:bolger@yahoogroups.com
Subject: [bolger] Re: latex house paint
--- In bolger@y..., Richard <rocwandrer@p...> wrote:
>
> Ok, so i have more questions :-) it seems to me that glassing the
outside of a boat that is strong
> enough, will not benefit me anything in additional strength. I
fail
to see how having epoxy inside of
> fiberglass strands makes a boat more waterproof that having epoxy
"painted" onto the outside of the
> boat. I am not saying it doesn't, i am asking why it does if it
does.
Hi Richard,
Think of fiberglass cloth and epoxy as reinforced concrete. Without
the steel concrete strength is greatly limited. You need a lot more
of
it for it to do its job. I believe the analogy applies to fiberglass
reinforced epoxy over wood. The cloth (and wood) give the epoxy its
strength. Without the cloth you don't have impact resistence. I don't
think cloth would increase the impermiability of the system all that
much but it does protect the integrity of the system.
>
> my boat will be in the water less than 12 hours at a time. it will
be in indoor storage for not less
> than 90% of its life.
>
> I hate fiberglass. i never seem to do it right. should i
>
> 1 primer and paint the boat with latex porch paint.
>
> i have been told that glassing the boat is needed for a good
service
life. i don't mind touch up and
> dave carnell states that epoxy coating without glassing is a waste
of money. he doesn't say why.
Richard like so many things, "it depends". Glass is a reinforcement.
If you don't need reinforcement you don't need glass. Epoxy is a
vapor
barrier/moisture barrier. If that is all you need (you don't NEED
the reinforcement) don't glass. If you are not going to glass the
bottom, chines, stem etc I wouldn't epoxy them either because
without
glass the epoxy is subject to damage and the moisture will
get in. Similarly with a break in the epoxy barrier, rot spores can
get in too.
> 2 "paint" the boat with epoxy (x coats?) and sand and primer and
paint with porch paint.
Gougeons say 2 coats minimum, beyond 4 or 5 coats there is little
return for the expense of adding more epoxy.
>
> 3 glass the boat with epoxy and sand and primer and paint.
>
>I would recommend #2 for topsides , #3 for bottoms to above the
waterline, chines, stems, decks and sheerline/deck joint if there is
one.
Bob Chamberland
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--- In bolger@y..., Richard <rocwandrer@p...> wrote:
to see how having epoxy inside of
Hi Richard,
Think of fiberglass cloth and epoxy as reinforced concrete. Without
the steel concrete strength is greatly limited. You need a lot more
of
it for it to do its job. I believe the analogy applies to fiberglass
reinforced epoxy over wood. The cloth (and wood) give the epoxy its
strength. Without the cloth you don't have impact resistence. I don't
think cloth would increase the impermiability of the system all that
much but it does protect the integrity of the system.
life. i don't mind touch up and
Richard like so many things, "it depends". Glass is a reinforcement.
If you don't need reinforcement you don't need glass. Epoxy is a
vapor
barrier/moisture barrier. If that is all you need (you don't NEED
the reinforcement) don't glass. If you are not going to glass the
bottom, chines, stem etc I wouldn't epoxy them either because
without
glass the epoxy is subject to damage and the moisture will
get in. Similarly with a break in the epoxy barrier, rot spores can
get in too.
Gougeons say 2 coats minimum, beyond 4 or 5 coats there is little
return for the expense of adding more epoxy.
one.
Bob Chamberland
>outside of a boat that is strong
> Ok, so i have more questions :-) it seems to me that glassing the
> enough, will not benefit me anything in additional strength. Ifail
to see how having epoxy inside of
> fiberglass strands makes a boat more waterproof that having epoxy"painted" onto the outside of the
> boat. I am not saying it doesn't, i am asking why it does if itdoes.
Hi Richard,
Think of fiberglass cloth and epoxy as reinforced concrete. Without
the steel concrete strength is greatly limited. You need a lot more
of
it for it to do its job. I believe the analogy applies to fiberglass
reinforced epoxy over wood. The cloth (and wood) give the epoxy its
strength. Without the cloth you don't have impact resistence. I don't
think cloth would increase the impermiability of the system all that
much but it does protect the integrity of the system.
>be in indoor storage for not less
> my boat will be in the water less than 12 hours at a time. it will
> than 90% of its life.service
>
> I hate fiberglass. i never seem to do it right. should i
>
> 1 primer and paint the boat with latex porch paint.
>
> i have been told that glassing the boat is needed for a good
life. i don't mind touch up and
> dave carnell states that epoxy coating without glassing is a wasteof money. he doesn't say why.
Richard like so many things, "it depends". Glass is a reinforcement.
If you don't need reinforcement you don't need glass. Epoxy is a
vapor
barrier/moisture barrier. If that is all you need (you don't NEED
the reinforcement) don't glass. If you are not going to glass the
bottom, chines, stem etc I wouldn't epoxy them either because
without
glass the epoxy is subject to damage and the moisture will
get in. Similarly with a break in the epoxy barrier, rot spores can
get in too.
> 2 "paint" the boat with epoxy (x coats?) and sand and primer andpaint with porch paint.
Gougeons say 2 coats minimum, beyond 4 or 5 coats there is little
return for the expense of adding more epoxy.
>waterline, chines, stems, decks and sheerline/deck joint if there is
> 3 glass the boat with epoxy and sand and primer and paint.
>
>I would recommend #2 for topsides , #3 for bottoms to above the
one.
Bob Chamberland
One reason to cover epoxy with paint is that UV breaks it down rather
rapidly.
rapidly.
On Thu, 23 Aug 2001, Richard wrote:
that's why people use it. It prevents checking, which epoxy alone does
not (many, many, many folk have posted this experience here and
elsewhere). It also works as a scrim, that is, it holds the right amount
of epoxy on the surface--more per coat, and the same amount acorss the
whole surface.
But most importantly, it adds strength and abrasion resistance in a way
that epoxy alone does not. Fiberglassing is not all that hard. Many
books and websites say how to do it. In short:
Use the right weight (often 6oz on small boats).
Lay it down dry (my preference).
Roll/squeegee out enough, and squeege excess out, so that the glass
texture clearly comes through.
Allow to set, but not fully.
Fill the weave with epoxy/microballons/fairing compound.
Sand and fair.
Takes a couple of sessions on a small boat, and I find it satisfying.
> Ok, so i have more questions :-) it seems to me that glassing theThis last one is what to do. The fiberglass does a lot of work, and
> outside of a boat that is strong enough, will not benefit me anything
> in additional strength. I fail to see how having epoxy inside of
> fiberglass strands makes a boat more waterproof that having epoxy
> "painted" onto the outside of the boat. I am not saying it doesn't, i
> am asking why it does if it does.
> 3 glass the boat with epoxy and sand and primer and paint.
that's why people use it. It prevents checking, which epoxy alone does
not (many, many, many folk have posted this experience here and
elsewhere). It also works as a scrim, that is, it holds the right amount
of epoxy on the surface--more per coat, and the same amount acorss the
whole surface.
But most importantly, it adds strength and abrasion resistance in a way
that epoxy alone does not. Fiberglassing is not all that hard. Many
books and websites say how to do it. In short:
Use the right weight (often 6oz on small boats).
Lay it down dry (my preference).
Roll/squeegee out enough, and squeege excess out, so that the glass
texture clearly comes through.
Allow to set, but not fully.
Fill the weave with epoxy/microballons/fairing compound.
Sand and fair.
Takes a couple of sessions on a small boat, and I find it satisfying.
>Glassing and epoxy eliminate for the most part the tendency for plywood toIn my experience with paint only, epoxy "sealing" and paint, or
>check.
>
>In a nutshell, I myself would not use just epoxy. It would be either none,
>or used with glass.
epoxy, glass and paint; I'd say that either go cheap with paint only
or go big with epoxy, glass and paint.
Don't waste your time and money going epoxy only. It'll check just as
bad as paint alone.
BTW: You don't need heavy glass to prevent checking. I've got 3.6 oz
still looking good after 12 continuous months of being outside.
YIBB,
David
CRUMBLING EMPIRE PRODUCTIONS
134 West 26th St. 12th Floor
New York, New York 10001
http://www.crumblingempire.com
(212) 247-0296
Richard -
Glassing the outside of the hull is not for structural strength but for wear
resistance.
Let's say you lay down a coat of epoxy or two, a couple of coats of primer,
a coat or two of latex paint and then a coat of bottom paint (maybe skip the
bottom paint, if you're trailering exclusively). That is fine, as long as
the bottom of your boat never hits anything harder than water. The first
time you bang against a rock, slide a bit on a concrete launching ramp, or
even ground on a nice sandy bottom, you will open up ALL of those protective
coatings (and perhaps the face veneer of the plywood), and now your plywood
is exposed to the water, and that water is wicking into the layers of your
ply. The same story can be told of your topsides, with an anchor carelessly
dragged or dropped on deck, or even ground in dirt and sand.
Now, the same exact scenarios (rock, ramp, sand, anchor, whatever), except
this time you have a layer of fiberglas cloth protecting that plywood.
Unless the impact is incredibly severe, the worst you can do is expose the
fiberglas. your wood is protected. A LOT less chance of rot getting
established.
I have an Elegant Punt that stays in the water 5 months each year, and then
is upside down, ouside, uncovered, for the winter (in Northern Vermont --
the entire hull was buried in snow for 4 months last winter). I used high
quality latex house paints and primers as a finish. I was told "Oh, don't
bother fiberglasing the bottom," but I did it anyway. After seeing what
happens to the bottom through the course of a season, even on a lake (and
what happens to the un-fiberglased parts inside the boat or along the
rubrail, etc), I'm VERY glad I fiberglased the bottom.
One mistake to avoid with latex paint: do NOT use thick coats of primer or
paint. One or (if you must), two thin coats of primer and finish is all you
need. More or thicker coats won't offer any additional protection, but it
may encourage blistering and peeling. It also adds unnecessary weight.
Glassing the outside of the hull is not for structural strength but for wear
resistance.
Let's say you lay down a coat of epoxy or two, a couple of coats of primer,
a coat or two of latex paint and then a coat of bottom paint (maybe skip the
bottom paint, if you're trailering exclusively). That is fine, as long as
the bottom of your boat never hits anything harder than water. The first
time you bang against a rock, slide a bit on a concrete launching ramp, or
even ground on a nice sandy bottom, you will open up ALL of those protective
coatings (and perhaps the face veneer of the plywood), and now your plywood
is exposed to the water, and that water is wicking into the layers of your
ply. The same story can be told of your topsides, with an anchor carelessly
dragged or dropped on deck, or even ground in dirt and sand.
Now, the same exact scenarios (rock, ramp, sand, anchor, whatever), except
this time you have a layer of fiberglas cloth protecting that plywood.
Unless the impact is incredibly severe, the worst you can do is expose the
fiberglas. your wood is protected. A LOT less chance of rot getting
established.
I have an Elegant Punt that stays in the water 5 months each year, and then
is upside down, ouside, uncovered, for the winter (in Northern Vermont --
the entire hull was buried in snow for 4 months last winter). I used high
quality latex house paints and primers as a finish. I was told "Oh, don't
bother fiberglasing the bottom," but I did it anyway. After seeing what
happens to the bottom through the course of a season, even on a lake (and
what happens to the un-fiberglased parts inside the boat or along the
rubrail, etc), I'm VERY glad I fiberglased the bottom.
One mistake to avoid with latex paint: do NOT use thick coats of primer or
paint. One or (if you must), two thin coats of primer and finish is all you
need. More or thicker coats won't offer any additional protection, but it
may encourage blistering and peeling. It also adds unnecessary weight.
>From: Richard <rocwandrer@...>
>snip
>
>Ok, so i have more questions :-) it seems to me that glassing the outside
>of a boat that is strong
>enough, will not benefit me anything in additional strength. I fail to see
>how having epoxy inside of
>fiberglass strands makes a boat more waterproof that having epoxy "painted"
>onto the outside of the
>boat. I am not saying it doesn't, i am asking why it does if it does.
> <snip>
Just my 2 cents worth here.
Glassing and epoxy eliminate for the most part the tendency for plywood to
check. Checking creates cracks through the epoxy only coat and allows water
to enter the plywood. Not all plywood checks but I have heard that it has
happened to even the best. It has something to do with the different
densities of the woods used or the actual tree such as pine or fir can have
different densities internally.
These different densities will expand and contract at different rates and
amounts, hence checking. Glassing over the plywood will stop the checking,
though it can still check through in rare and extreme instances or so I've
heard.
It will also give it better abrasion protection than plain plywood for
beaching, rocks, etc.
We all have our own ideas on what works best and we have to live with the
fact that most plywood will check. If I wanted a minimal investment and
willing to store the boat protected from the elements, I'd forget the epoxy
and keep it well painted. On a bigger investment or for a boat that's going
to be kicked around, left outside poorly protected, get hard use, etc., go
epoxy and glass.
In a nutshell, I myself would not use just epoxy. It would be either none,
or used with glass.
Jeff
Glassing and epoxy eliminate for the most part the tendency for plywood to
check. Checking creates cracks through the epoxy only coat and allows water
to enter the plywood. Not all plywood checks but I have heard that it has
happened to even the best. It has something to do with the different
densities of the woods used or the actual tree such as pine or fir can have
different densities internally.
These different densities will expand and contract at different rates and
amounts, hence checking. Glassing over the plywood will stop the checking,
though it can still check through in rare and extreme instances or so I've
heard.
It will also give it better abrasion protection than plain plywood for
beaching, rocks, etc.
We all have our own ideas on what works best and we have to live with the
fact that most plywood will check. If I wanted a minimal investment and
willing to store the boat protected from the elements, I'd forget the epoxy
and keep it well painted. On a bigger investment or for a boat that's going
to be kicked around, left outside poorly protected, get hard use, etc., go
epoxy and glass.
In a nutshell, I myself would not use just epoxy. It would be either none,
or used with glass.
Jeff
----- Original Message -----
From: "Richard" <rocwandrer@...>
To: <bolger@yahoogroups.com>
Sent: Thursday, August 23, 2001 10:31 AM
Subject: [bolger] Re: latex house paint
> before i asked this question i look around a house paint oriented sites,
at boat paint sites Dave
> Carnell's site (very good write-up) etc. etc. I didn't feel confident
using any old 100% acrylic latex
> house paint until i had more info from other people with hands on
experience. I have gotten a number
> of replies to my query and every single one of them has been helpful!!!!!
>
> Thank you everyone!!!
>
> Ok, so i have more questions :-) it seems to me that glassing the outside
of a boat that is strong
> enough, will not benefit me anything in additional strength. I fail to
see how having epoxy inside of
> fiberglass strands makes a boat more waterproof that having epoxy
"painted" onto the outside of the
> boat. I am not saying it doesn't, i am asking why it does if it does.
>
> my boat will be in the water less than 12 hours at a time. it will be in
indoor storage for not less
> than 90% of its life.
>
> I hate fiberglass. i never seem to do it right. should i
>
> 1 primer and paint the boat with latex porch paint.
>
> i have been told that glassing the boat is needed for a good service life.
i don't mind touch up and
> dave carnell states that epoxy coating without glassing is a waste of
money. he doesn't say why. it
> would seem to me that if epoxy is a greater water barrier (can that be
implied from the fact that it is
> a greater vapor barrier?) than it is like a better paint job.
>
> 2 "paint" the boat with epoxy (x coats?) and sand and primer and paint
with porch paint.
>
> many plans providers that also sell epoxy seem to recommend this approach,
in addition to glassing....
> hmm
>
> 3 glass the boat with epoxy and sand and primer and paint.
>
>
> thanks again,
> Richard
>
>
>
> Message: 15
> Date: Thu, 23 Aug 2001 00:36:35 -0000
> From:dcraig@...
> Subject: Re: latex paints
>
> Richard, I would suggest going to Dave Carnell's Boat Building Page
> and reading his article on Latex Paints For Boats - I would give him
> some credence since he is a chemical engineer.
>
> > i have a quick (i hope) question about latex house paints. I have
> been reading some propaganda
> > (advertisements) that talk about letting the wood "breath." i know
> that proper moisture content wood
> > should not need to "breath", but does this mean that latex house
> paint is formulated to be porous?
>
> That's pretty much exactly what it means. In an earlier life, I was
> making carved wooden signs for a living and I did NOT want paint
> blistering. These signs were going to be exposed to sun and elements
> 24-7-365, year after year. I researched the literature from
> experienced sign makers and learned that the best protective coating
> was not oil paint but latex. Oil paint had the best reputation
> because it had been used for centuries - it was all that was
> available, not counting shellac and lacquer, milk paint etc. - and
> latex was new and crappy at first, but excellent today.
> The proper moisture content of wood is not worth bothering about,
> for our purposes, because kiln dried values are worthless as soon as
> you stack the wood in an open air warehouse - and that's where most of
> us find our stuff.
> All wood, seasoned or not, has moisture in it to a greater or
> lesser degree. Depending on the moisture content inside the wood and
> the outside climatic conditions, oil paint can be a great coating for
> many years or it can start to blister in a few years. The reason for
> blistering is that the moisture wants out and the oil paint won't let
> it out, so the wood and paint separate. Oil paint is not porous for
> the passage of moisture.
> I recently scraped and repainted a fancy fence that had been
> painted with oil six years ago. In places the paint pulled off in
> strips. Underneath, the wood was green with fungus and wet; wet, even
> after five weeks of hot dry weather. There was nothing wrong with the
> paint, it was thick and the strips were strong - but there was a
> failure in the bond between paint and wood.
> Latex paint, in my humble opinion based on research (reading) and
> experimentation, is porous to the passage of moisture and will not
> blister (that doesn't mean it won't strip off epoxy that has not been
> properly prepared). The best paint I found for signage was Pratt &
> Lambert exterior acrylic/latex house trim paint. It has a high level
> of pigment content, so color retention lasts longer under weather.
> Signs I painted six years ago with acrylic/latex have still not
> blistered.
> Honestly, I do not know, or have an opinion, on how latex would
> perform on the bottom of a boat that sits in the water all season. But
> for a dry sailer, I would use it.
>
> how
> > do i tell an intentionally porous latex house paint from a good one
> for a boat.
>
> For a boat, I would consider an acrylic/latex 'deck and porch'
> enamel - paint that is intended to be walked on should be the most
> durable.
> I've had this discussion with so-called house painters who do this
> for a living, and I hear things like 'latex paints on a fence or sign
> are good, but you still have to prime it with an oil base primer.' Go
> figure.
>
> Don Craig
> --
> To invent, you need a good imagination and a pile of junk. --Thomas Edison
>
>
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - pls take "personals" off-list, stay on topic, and punctuate
> - add your comments at the TOP and SIGN your posts, snip all you like
> - To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
01930, Fax: (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject tohttp://docs.yahoo.com/info/terms/
>
>
before i asked this question i look around a house paint oriented sites, at boat paint sites Dave
Carnell's site (very good write-up) etc. etc. I didn't feel confident using any old 100% acrylic latex
house paint until i had more info from other people with hands on experience. I have gotten a number
of replies to my query and every single one of them has been helpful!!!!!
Thank you everyone!!!
Ok, so i have more questions :-) it seems to me that glassing the outside of a boat that is strong
enough, will not benefit me anything in additional strength. I fail to see how having epoxy inside of
fiberglass strands makes a boat more waterproof that having epoxy "painted" onto the outside of the
boat. I am not saying it doesn't, i am asking why it does if it does.
my boat will be in the water less than 12 hours at a time. it will be in indoor storage for not less
than 90% of its life.
I hate fiberglass. i never seem to do it right. should i
1 primer and paint the boat with latex porch paint.
i have been told that glassing the boat is needed for a good service life. i don't mind touch up and
dave carnell states that epoxy coating without glassing is a waste of money. he doesn't say why. it
would seem to me that if epoxy is a greater water barrier (can that be implied from the fact that it is
a greater vapor barrier?) than it is like a better paint job.
2 "paint" the boat with epoxy (x coats?) and sand and primer and paint with porch paint.
many plans providers that also sell epoxy seem to recommend this approach, in addition to glassing....
hmm
3 glass the boat with epoxy and sand and primer and paint.
thanks again,
Richard
Message: 15
Date: Thu, 23 Aug 2001 00:36:35 -0000
From:dcraig@...
Subject: Re: latex paints
Richard, I would suggest going to Dave Carnell's Boat Building Page
and reading his article on Latex Paints For Boats - I would give him
some credence since he is a chemical engineer.
That's pretty much exactly what it means. In an earlier life, I was
making carved wooden signs for a living and I did NOT want paint
blistering. These signs were going to be exposed to sun and elements
24-7-365, year after year. I researched the literature from
experienced sign makers and learned that the best protective coating
was not oil paint but latex. Oil paint had the best reputation
because it had been used for centuries - it was all that was
available, not counting shellac and lacquer, milk paint etc. - and
latex was new and crappy at first, but excellent today.
The proper moisture content of wood is not worth bothering about,
for our purposes, because kiln dried values are worthless as soon as
you stack the wood in an open air warehouse - and that's where most of
us find our stuff.
All wood, seasoned or not, has moisture in it to a greater or
lesser degree. Depending on the moisture content inside the wood and
the outside climatic conditions, oil paint can be a great coating for
many years or it can start to blister in a few years. The reason for
blistering is that the moisture wants out and the oil paint won't let
it out, so the wood and paint separate. Oil paint is not porous for
the passage of moisture.
I recently scraped and repainted a fancy fence that had been
painted with oil six years ago. In places the paint pulled off in
strips. Underneath, the wood was green with fungus and wet; wet, even
after five weeks of hot dry weather. There was nothing wrong with the
paint, it was thick and the strips were strong - but there was a
failure in the bond between paint and wood.
Latex paint, in my humble opinion based on research (reading) and
experimentation, is porous to the passage of moisture and will not
blister (that doesn't mean it won't strip off epoxy that has not been
properly prepared). The best paint I found for signage was Pratt &
Lambert exterior acrylic/latex house trim paint. It has a high level
of pigment content, so color retention lasts longer under weather.
Signs I painted six years ago with acrylic/latex have still not
blistered.
Honestly, I do not know, or have an opinion, on how latex would
perform on the bottom of a boat that sits in the water all season. But
for a dry sailer, I would use it.
how
For a boat, I would consider an acrylic/latex 'deck and porch'
enamel - paint that is intended to be walked on should be the most
durable.
I've had this discussion with so-called house painters who do this
for a living, and I hear things like 'latex paints on a fence or sign
are good, but you still have to prime it with an oil base primer.' Go
figure.
Don Craig
--
To invent, you need a good imagination and a pile of junk. --Thomas Edison
Carnell's site (very good write-up) etc. etc. I didn't feel confident using any old 100% acrylic latex
house paint until i had more info from other people with hands on experience. I have gotten a number
of replies to my query and every single one of them has been helpful!!!!!
Thank you everyone!!!
Ok, so i have more questions :-) it seems to me that glassing the outside of a boat that is strong
enough, will not benefit me anything in additional strength. I fail to see how having epoxy inside of
fiberglass strands makes a boat more waterproof that having epoxy "painted" onto the outside of the
boat. I am not saying it doesn't, i am asking why it does if it does.
my boat will be in the water less than 12 hours at a time. it will be in indoor storage for not less
than 90% of its life.
I hate fiberglass. i never seem to do it right. should i
1 primer and paint the boat with latex porch paint.
i have been told that glassing the boat is needed for a good service life. i don't mind touch up and
dave carnell states that epoxy coating without glassing is a waste of money. he doesn't say why. it
would seem to me that if epoxy is a greater water barrier (can that be implied from the fact that it is
a greater vapor barrier?) than it is like a better paint job.
2 "paint" the boat with epoxy (x coats?) and sand and primer and paint with porch paint.
many plans providers that also sell epoxy seem to recommend this approach, in addition to glassing....
hmm
3 glass the boat with epoxy and sand and primer and paint.
thanks again,
Richard
Message: 15
Date: Thu, 23 Aug 2001 00:36:35 -0000
From:dcraig@...
Subject: Re: latex paints
Richard, I would suggest going to Dave Carnell's Boat Building Page
and reading his article on Latex Paints For Boats - I would give him
some credence since he is a chemical engineer.
> i have a quick (i hope) question about latex house paints. I havebeen reading some propaganda
> (advertisements) that talk about letting the wood "breath." i knowthat proper moisture content wood
> should not need to "breath", but does this mean that latex housepaint is formulated to be porous?
That's pretty much exactly what it means. In an earlier life, I was
making carved wooden signs for a living and I did NOT want paint
blistering. These signs were going to be exposed to sun and elements
24-7-365, year after year. I researched the literature from
experienced sign makers and learned that the best protective coating
was not oil paint but latex. Oil paint had the best reputation
because it had been used for centuries - it was all that was
available, not counting shellac and lacquer, milk paint etc. - and
latex was new and crappy at first, but excellent today.
The proper moisture content of wood is not worth bothering about,
for our purposes, because kiln dried values are worthless as soon as
you stack the wood in an open air warehouse - and that's where most of
us find our stuff.
All wood, seasoned or not, has moisture in it to a greater or
lesser degree. Depending on the moisture content inside the wood and
the outside climatic conditions, oil paint can be a great coating for
many years or it can start to blister in a few years. The reason for
blistering is that the moisture wants out and the oil paint won't let
it out, so the wood and paint separate. Oil paint is not porous for
the passage of moisture.
I recently scraped and repainted a fancy fence that had been
painted with oil six years ago. In places the paint pulled off in
strips. Underneath, the wood was green with fungus and wet; wet, even
after five weeks of hot dry weather. There was nothing wrong with the
paint, it was thick and the strips were strong - but there was a
failure in the bond between paint and wood.
Latex paint, in my humble opinion based on research (reading) and
experimentation, is porous to the passage of moisture and will not
blister (that doesn't mean it won't strip off epoxy that has not been
properly prepared). The best paint I found for signage was Pratt &
Lambert exterior acrylic/latex house trim paint. It has a high level
of pigment content, so color retention lasts longer under weather.
Signs I painted six years ago with acrylic/latex have still not
blistered.
Honestly, I do not know, or have an opinion, on how latex would
perform on the bottom of a boat that sits in the water all season. But
for a dry sailer, I would use it.
how
> do i tell an intentionally porous latex house paint from a good onefor a boat.
For a boat, I would consider an acrylic/latex 'deck and porch'
enamel - paint that is intended to be walked on should be the most
durable.
I've had this discussion with so-called house painters who do this
for a living, and I hear things like 'latex paints on a fence or sign
are good, but you still have to prime it with an oil base primer.' Go
figure.
Don Craig
--
To invent, you need a good imagination and a pile of junk. --Thomas Edison