On Thu, 25 Mar 2010 22:54:40 -0500, cavelamb
wrote:

Bruce wrote:

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester. Feather the gouge out and pack it with epoxy saturated
mat. If you are worried about osmosis, after you have made your
repairs grind the entire underwater area down to a good solid surface
and roll on two coats of epoxy. Put the first coat on and let it set
up until it isn't sticky but you can still mark it with your finger
and then roll on the second coat. After the second coat sets up, but
still not hard, roll on a coat of epoxy high build primer and leave it
for a day or so.

If you don't wait long enough after the first coat of epoxy the second
coat will be very heavy as you have to slop it onto a sticky surface
and if you paint the primer too soon it will craze - tiny cracks all
over the place. The reason for all this hoopdi-do is that if you let
the usual epoxy set hard it will have an oily film on it called "amine
blush" and then you have to wash the whole thing clean, let it dry,
wipe it with thinner, and repaint.

Finish sand and two coats of two part polyurethane. You'll be good
for ten years or so.... However it is more costly then polyester and
barn paint.

Cheers,

Bruce


I gotta say, Bruce, about the only thing that could be done beyond that
it a couple of layers of new glass over the entire underwater hull.
A close out layer that seals off all the possible cracks and crevasses from
water incursion.

Not that such would be economically feasible...

Richard


Yes, and I've seen a number of boats that were treated that way. Grind
off all the gel coat and let it set and dry for about half a year.
Then fair the hull and cover it with one layer of glass cloth. It is
expensive.

Over here the labor costs aren't expensive and even materials aren't
too bad but the yard rent is going to get you. All the yards, except
one hard stand area are commercial yards and charge commercial rates
for space. You might get a better rate for a six month stay if you
picked a period when the yard wasn't busy, but that is usually in the
rainy season... And, I've always wondered how much drying out goes on
when humidity is in the 80s and 90s?

Cheers,

Bruce

On Fri, 26 Mar 2010 10:30:17 -0400, I am Tosk
wrote:

In article ,
says...

Bruce wrote:

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester. Feather the gouge out and pack it with epoxy saturated
mat. If you are worried about osmosis, after you have made your
repairs grind the entire underwater area down to a good solid surface
and roll on two coats of epoxy. Put the first coat on and let it set
up until it isn't sticky but you can still mark it with your finger
and then roll on the second coat. After the second coat sets up, but
still not hard, roll on a coat of epoxy high build primer and leave it
for a day or so.

If you don't wait long enough after the first coat of epoxy the second
coat will be very heavy as you have to slop it onto a sticky surface
and if you paint the primer too soon it will craze - tiny cracks all
over the place. The reason for all this hoopdi-do is that if you let
the usual epoxy set hard it will have an oily film on it called "amine
blush" and then you have to wash the whole thing clean, let it dry,
wipe it with thinner, and repaint.

Finish sand and two coats of two part polyurethane. You'll be good
for ten years or so.... However it is more costly then polyester and
barn paint.

Cheers,

Bruce


I gotta say, Bruce, about the only thing that could be done beyond that
it a couple of layers of new glass over the entire underwater hull.
A close out layer that seals off all the possible cracks and crevasses from
water incursion.

Not that such would be economically feasible...

Richard

Nor would I ever add that much weight to a proven design... Couldn't all
that weight make it sit differently in the water and effect it's
efficiency and safety?

Scotty

I believe that the adding of another laminate is probably not adding
much weight as it is usually intended to replace the material that was
ground off.

Another point is that worrying about weight on a cruising boat is
usually futile since as soon as you get it built the owner piles a
several hundred liters of water and fuel in Jerry cans on the deck,
hangs two outboard engines on the stern rail, four anchors, a couple
of tool boxes and a horde of parts down below, two gas bottles, spare
sails, old rope, adds davits so he can hoist out his dinghy, two
spinnaker poles and adds a hard bimini.

When I cleaned out my 40 ft. boat, which had a design displacement of
nearly 10 tons it came up three inches :-)

Cheers,

Bruce

On Fri, 26 Mar 2010 09:00:45 -0700 (PDT), Tim
wrote:

On Mar 25, 8:53*am, Frogwatch wrote:
On Mar 23, 2:29*pm, Tim wrote:





On Mar 23, 7:42*am, Bruce wrote:

On Mon, 22 Mar 2010 19:33:17 -0700 (PDT), Tim
wrote:

OK, I posted this over on rec.boats, but there's to much politi-bs to
wade through, event though some people will give me some good advice.

I have a 1977 Marquis 23 ft'r which I'm wanting to sound out to make a
good river cruise this late summer/early fall, and I'm asking all
kinds of questions about GPS, radios charts etc. but that's beside the
point.

So here's my question to those experienced in hull and fiberglass
repair:

OK, in my never ending quest for info, I thought I'd look at my big
boat's hull. *I haven't' found any blisters, but the hull has had
something repaired on it in times past like to cover a gouge, or *hard
nicks. *Nothing big, but some type of a tanish-colored *'epoxy repair'
which has been applied to a couple spots on the port side, which are
anywhere from the size of your thumb print to no larger than a
"Kennedy half".

I've tapped around on the hull from about bow to stern and all sounds
solid with no dead thuds and nothing spongy. So I feel the integrity
of the fiberglass is in good shape.

I looked down the keel of the hull from the bow, and there have been
several nicks that though seem to be on the surface, I feel they need
to have some attention payed to them . I didn't see any sign of
fiberglass core actually showing through, however there were some
nicks that
have gone deep enough to look like they've gone through the gell coat,
to the green underlying fiberglass resin.

I don't think that the boat has been abused, but sometimes hitting a
good stick can cause such nicks, but this looks like it's tapped
against some hard heavy rocks like what you might find lining a dock
loading ramp or at a spill way.

I don't think that water has infiltrated the fiberglass or at least
nothing to cause blistering, but I am concerned a bit about it, that
it needs some repair.

One guy who likes to think with his mouth and not his mind looked at
the nicks and suggested that I dab some fingernail polish on it.

For pete's sake

I know there's lots of fiberglass repair products out there but seeing
I don't know much about it, I'd like somebody to recommend to me the
choicest products and repair procedures. I don't know much about it,
but am willing to try.

Thanks for the consideration.

Tim

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester. Feather the gouge out and pack it with epoxy saturated
mat. If you are worried about osmosis, after you have made your
repairs grind the entire underwater area down to a good solid surface
and roll on two coats of epoxy. Put the first coat on and let it set
up until it isn't sticky but you can still mark it with your finger
and then roll on the second coat. *After the second coat sets up, but
still not hard, roll on a coat of epoxy high build primer and leave it
for a day or so.

If you don't wait long enough after the first coat of epoxy the second
coat will be very heavy as you have to slop it onto a sticky surface
and if you paint the primer too soon it will craze - tiny cracks all
over the place. The reason for all this hoopdi-do is that if you let
the usual epoxy set hard it will have an oily film on it called "amine
blush" and then you have to wash the whole thing clean, let it dry,
wipe it with thinner, and repaint.

*Finish sand and two coats of two part polyurethane. You'll be good
for ten years or so.... However it is more costly then polyester and
barn paint.

Cheers,

Bruce- Hide quoted text -

- Show quoted text -

Thank for the replys. *I've gotten a few good responses "over there'
too!

Before you do ANYTHING about blisters, google "Pascoe, boat surveying"
and read his stuff on blisters. *There are very few cases where
blisters caused any problems. *In almost all cases they are merely
cosmetic and below the water where they cannot be seen. *I agree with
him that any "repairs" you make will actually make the blistering
worse. *Unless you can identify a real structural problem, forget em
and go cruising.- Hide quoted text -

- Show quoted text -

I haven't found any signs of blistering, and I've looked the hull over
pretty good. I'm concerned about the deep scratches and chips in the
gell coat and in a couple places you can see the resin core of the
fiberglass.Theres no fiber hars hanging out and o deep gouges. and I
haven't found any soft spots.

Basically, I'm just wanting to make sure I dont' get any water
intrussion into the hull itself and avoid future problems.


Frankly I wouldn't worry about it. If you want to make it look better
grind the nicks and scrapes out and dish the area a bit and then fill
them with an epoxy filler that contains chopped glass or Colloidal
Silica (do not use micro-balloons as a filler for this) sand fair and
smooth and paint with one coat of epoxy resin.

Have a look at the WEST system site, they have good instructions for
making almost every kind of repair or modification on fiberglass
structures.

As for water intrusion, I wouldn't get too worried about it as osmosis
is tied very closely to improper resin mixes. True that fiberglass
will ultimately absorb some water but it is not an overnight
phenomena.


Cheers,

Bruce

In article , Bruce wrote:

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester.

[snip]

Please excuse my ignorance. Are polyester and epoxy the same thing?
Also, you say 'assuming the hull is polyester', do you mean as opposed
to wood, steel or aluminium?

OK, maybe I should know some of this stuff, especially as my boat is FG,
but are there different resins used to bond FG? If so, when carrying out
repairs should one stick to the same type or does it not matter once
it's all hardened?

There are a couple of dings on some corners (yes, I did both of them,
but I'm getting better), I say corners, but they're hard edges, not
curves, one at the bow, and one where the transom joints the port side.
Both of these parts have already been coated with what looks like paint
- it has brush-strokes, unlike the rest of the hull - and the strip
extends about an inch onto each surface. It's possible a previous owner
tidied up similar knocks the same way... anyway, I'd like to repair
those dings as they aren't attractive and are a constant reminder of
abuse I'd like to put behind me. I'll have a look at the West site, but
I want to be sure of the answers to my two questions before I tackle
these.

Interesting reading so far, and thank you for any help you can give with
my questions.


Justin.

--
Justin C, by the sea.

In article ,
says...

In article , Bruce wrote:

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester.

[snip]

Please excuse my ignorance. Are polyester and epoxy the same thing?
Also, you say 'assuming the hull is polyester', do you mean as opposed
to wood, steel or aluminium?

OK, maybe I should know some of this stuff, especially as my boat is FG,
but are there different resins used to bond FG? If so, when carrying out
repairs should one stick to the same type or does it not matter once
it's all hardened?

There are a couple of dings on some corners (yes, I did both of them,
but I'm getting better), I say corners, but they're hard edges, not
curves, one at the bow, and one where the transom joints the port side.
Both of these parts have already been coated with what looks like paint
- it has brush-strokes, unlike the rest of the hull - and the strip
extends about an inch onto each surface. It's possible a previous owner
tidied up similar knocks the same way... anyway, I'd like to repair
those dings as they aren't attractive and are a constant reminder of
abuse I'd like to put behind me. I'll have a look at the West site, but
I want to be sure of the answers to my two questions before I tackle
these.

Interesting reading so far, and thank you for any help you can give with
my questions.


Justin.

Epoxy and Polyester are different things. Polyester is generally used
for laminating like building your FG boat, Epoxy has more adhesive
properties and is used for types of construction other than laminating.
Epoxy can be used for laminating but it would be expensive and the
process would be tedious.

Rather than go through it all again, look back just about a week for
Tim's thread on the exact same subject. It is full of everything you are
looking for here.

Scotty

--
For a great time, go here first... http://tinyurl.com/ygqxs5v

On Mon, 29 Mar 2010 20:03:05 +0100, Justin C
wrote:

In article , Bruce wrote:

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester.

[snip]

Please excuse my ignorance. Are polyester and epoxy the same thing?
Also, you say 'assuming the hull is polyester', do you mean as opposed
to wood, steel or aluminium?

No, as opposed to other composites. "composite material, properly
known as fiber-reinforced polymer (FRP) or glass-reinforced plastic
(GRP and commonly called "fiberglass" in popular usage."

Polyester and epoxy are not the same. In general terms, epoxy is a
stronger material and polyester is a cheaper material. Retailers here
are selling epoxy resin at nearly double the price of polyester. Epoxy
bonds well to many things, including polyester while polyester bonds
less well to most things, including epoxy. However, as polyester bonds
to itself satisfactorily it is normally used for constructing
"fiberglass" items, such as boats, as strength is adequate and price
is low while epoxy is often used to repair "fiberglass" as it is
stronger and bonds well.

However, having said that there are may variables. Repairing a
fiberglass hull can frequently be done with polyester, and making a
plywood boat is often done with epoxy. Of course there are reasons to
select one, or the other, what is used to construct a F1 car tub, for
instance, is probably not the ideal material for a fishing boat.

OK, maybe I should know some of this stuff, especially as my boat is FG,
but are there different resins used to bond FG? If so, when carrying out
repairs should one stick to the same type or does it not matter once
it's all hardened?

In practical terms the strength of the materials probably isn't as
important as the ability to bond to whatever you are repairing.

There are a couple of dings on some corners (yes, I did both of them,
but I'm getting better), I say corners, but they're hard edges, not
curves, one at the bow, and one where the transom joints the port side.
Both of these parts have already been coated with what looks like paint
- it has brush-strokes, unlike the rest of the hull - and the strip
extends about an inch onto each surface. It's possible a previous owner
tidied up similar knocks the same way... anyway, I'd like to repair
those dings as they aren't attractive and are a constant reminder of
abuse I'd like to put behind me. I'll have a look at the West site, but
I want to be sure of the answers to my two questions before I tackle
these.

If these areas are gel-coat then you can't match the finish unless you
apply gel-cost over your repair, which can be done but isn't a
particularly simple task. In addition, no matter that the gel-coat
looks white if it is very old you will discover that new, white,
gel-coat doesn't match in color.

Interesting reading so far, and thank you for any help you can give with
my questions.


Justin.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Bruce wrote:
On Mon, 29 Mar 2010 20:03:05 +0100, Justin C
wrote:


In article , Bruce wrote:

I just went through a fairly extensive blister repair and basically if
you use epoxy and fill gouges with chopped mat and epoxy the repair
will likely be stronger then the original hull, assuming that the hull
is polyester.

[snip]

Please excuse my ignorance. Are polyester and epoxy the same thing?
Also, you say 'assuming the hull is polyester', do you mean as opposed
to wood, steel or aluminium?


No, as opposed to other composites. "composite material, properly
known as fiber-reinforced polymer (FRP) or glass-reinforced plastic
(GRP and commonly called "fiberglass" in popular usage."

Polyester and epoxy are not the same. In general terms, epoxy is a
stronger material and polyester is a cheaper material. Retailers here
are selling epoxy resin at nearly double the price of polyester. Epoxy
bonds well to many things, including polyester while polyester bonds
less well to most things, including epoxy. However, as polyester bonds
to itself satisfactorily it is normally used for constructing
"fiberglass" items, such as boats, as strength is adequate and price
is low while epoxy is often used to repair "fiberglass" as it is
stronger and bonds well.

However, having said that there are may variables. Repairing a
fiberglass hull can frequently be done with polyester, and making a
plywood boat is often done with epoxy. Of course there are reasons to
select one, or the other, what is used to construct a F1 car tub, for
instance, is probably not the ideal material for a fishing boat.


OK, maybe I should know some of this stuff, especially as my boat is FG,
but are there different resins used to bond FG? If so, when carrying out
repairs should one stick to the same type or does it not matter once
it's all hardened?


In practical terms the strength of the materials probably isn't as
important as the ability to bond to whatever you are repairing.


There are a couple of dings on some corners (yes, I did both of them,
but I'm getting better), I say corners, but they're hard edges, not
curves, one at the bow, and one where the transom joints the port side.
Both of these parts have already been coated with what looks like paint
- it has brush-strokes, unlike the rest of the hull - and the strip
extends about an inch onto each surface. It's possible a previous owner
tidied up similar knocks the same way... anyway, I'd like to repair
those dings as they aren't attractive and are a constant reminder of
abuse I'd like to put behind me. I'll have a look at the West site, but
I want to be sure of the answers to my two questions before I tackle
these.


If these areas are gel-coat then you can't match the finish unless you
apply gel-cost over your repair, which can be done but isn't a
particularly simple task. In addition, no matter that the gel-coat
looks white if it is very old you will discover that new, white,
gel-coat doesn't match in color.


Interesting reading so far, and thank you for any help you can give with
my questions.

yes, polyester/fiberglass resin as what most fiberglass boats are made
from. Epoxy resin in different - better and more expensive.
As far as blisters - they are generally considered more cosmetic - never
heard of any boats ever sinking due to blisters, but folks like to fix
them anyway.

paul oman - progressive epoxy polymers inc

In article , I am Tosk wrote:
In article ,
says...
Please excuse my ignorance. Are polyester and epoxy the same thing?
Also, you say 'assuming the hull is polyester', do you mean as opposed
to wood, steel or aluminium?

[snip]

Epoxy and Polyester are different things. Polyester is generally used
for laminating like building your FG boat, Epoxy has more adhesive
properties and is used for types of construction other than laminating.
Epoxy can be used for laminating but it would be expensive and the
process would be tedious.

Rather than go through it all again, look back just about a week for
Tim's thread on the exact same subject. It is full of everything you are
looking for here.

I'm not sure if you meant this thread (which mentioned repairs) or that
long one where there was talk of chemical reactions, catalysts and the
linking of molecules, but I re-read them both and have a better idea
now. I skipped most of the second thread due to it being so far over my
head that I didn't understand, but reading it whole, instead of
piecemeal as people replied back and forth, it makes more sense to me
now.

Thanks for the pointer.

Justin.

--
Justin C, by the sea.

In article ,
says...

In article , I am Tosk wrote:
In article ,
says...
Please excuse my ignorance. Are polyester and epoxy the same thing?
Also, you say 'assuming the hull is polyester', do you mean as opposed
to wood, steel or aluminium?

[snip]

Epoxy and Polyester are different things. Polyester is generally used
for laminating like building your FG boat, Epoxy has more adhesive
properties and is used for types of construction other than laminating.
Epoxy can be used for laminating but it would be expensive and the
process would be tedious.

Rather than go through it all again, look back just about a week for
Tim's thread on the exact same subject. It is full of everything you are
looking for here.

I'm not sure if you meant this thread (which mentioned repairs) or that
long one where there was talk of chemical reactions, catalysts and the
linking of molecules, but I re-read them both and have a better idea
now. I skipped most of the second thread due to it being so far over my
head that I didn't understand, but reading it whole, instead of
piecemeal as people replied back and forth, it makes more sense to me
now.

Thanks for the pointer.

Justin.

Glad I caught the question.. Good luck.

Scotty

--
For a great time, go here first... http://tinyurl.com/ygqxs5v