Largest Piece Or Smallest Piece First When Laying FiberglassCloth Over a Tapered Edge?
 

On the OP's question, smallest piece first will be stronger
(assuming a good bond). Depends on what you want. You can
also put down more than 3 layers wet-on-wet, I've done five
or six at a time (using slow set resin) and it works just
fine. The prep work is the key.


And don't forget to put a sheet of plastic between the core and resin
if you're working next to the core. (the foam reacts with the epoxy
and gasses, leaving voids).


???

Isn't the point to bond the core to the surface? If you're
getting that much reaction & gas, you're doing something wrong.


dog wrote:
This is rather bad advice. In almost all cases, you WANT THE RESIN AND
PATCH TO BOND TO THE CORE. Putting plastic between the core and the
resin leaves a void too, just not one filled with gasses. Most cores DO
NOT react to Epoxy by dissolving and gassing off... especially if the
core is a good end-grain balsa, which it is on the better boats.

Not tostart an argument, but there are many foams to choose
from and some are lighter & stronger than balsa.

... If the
core is not bonded to the repaired area, you have effectively created a
section that is pre-delaminated.

Yeah, that was kind of what I thought too. But you have to
keep in mind, everybody wants something different.

DSK

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

Jay,
I was referring to the Don Casey {hardcover} book. I have no problems with
Gougeon Brothers literature, I just consider them more 'pamphlets'. {They
call them 'manuals'}This is more due to their brevity and physical size
{note the 'punching' so they can be 'filed' in a loose-leaf notebook}.

They do a LOT of work & research. In certain ways they are the pioneers in
the field. However, if you read more of their stuff you will note a lot of
redundancy in the illustrations & text. This is because a lot of 'problems'
have the same 'solution'.

Looking at my comp of 'F'glass Boat Repair . . .' I looks like your looking
at Section 4.2.1 which refers back to Section 3.3. They are talking about
the fiberglass SKIN . . . this is only about 1/8 in thick, at maximum.
{Casey implies about 1in or more} Therefore, if you bevel the edges as shown
there would only be about 1/2 inch, or so, difference between largest &
smallest piece. Follow that with the rest of the outlined technique -
peel-ply, vacuum bagging, {or heavily rolling each layer}, implied
'wet-on-wet' application, etc. - and it really doesn't matter which is put
down first.

What ever you do, allow space for a 'smooth coat' of fairing material, and a
1/32in thick coat of Gelcoat, or paint topcoat to blend in with the rest of
the deck.

Regards & Good Luck,
Ron Magen
Backyard Boatshop

wrote in message
ups.com...
Yes, I have read both West System books and Don Casey's book very
carefully. That's why I discover the difference between their two
approaches. Otherwise, I might not even notice the difference.
SNIP

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

Yes, the wet-on-wet method is good and is the method that I intend to
use. But this doesn't seem to have anything to do with
smallest-piece-first, or largest-piece-first. Sound like we should use
wet-on-wet method regardless if we choose smallest-piece-first, or
largest-piece-first. Here, I assume that you are saying this: "Small
piece first or large piece first is not important; the fiberglass tape
will stick well as long as we use wet-on-wet method." Is my
understanding correct?

Thanks for sharing your experience in pre-wetting the fiberglass tapes
before laying them down on the surface. But I guess I will pass on
this one. I don't trust myself not to drip all over the place while I
carry the pre-wetted piece to the boat. Hopefully, other newsgroup
members will find a use of your method. I will stick with laying the
fiberglass cloth dry, blue-taping the fiberglass cloth in place, and
brushing the epoxy on the dry fiberglass cloth.

Thanks.

Jay Chan

Brian D wrote:
There's a simple fix for the smallest-piece-first method and the use of
fairing compound ...stop letting the tape cure in between applications of
tape. In other words, if you put the tape on wet-on-wet, then you don't
need to scrape, sand, fill with fairing compound, etcetera in between layers
just so you can properly taper the edges on the previous layer. The
"Gougeon Brothers on Boat Construction" book describes this technique, and
also recommends pre-wetting the fiberglass tape prior to installation. I
find that in the majority of installations, that pre-wetting and
installation of glass wet-on-wet can be done, and only once in awhile is
there reason to take a different approach. Here's my pre-wetting box:

http://www.glacierboats.com/tongass/...3-1336_img.jpg

I've built seams with as many as 3 layers of glass with the wet-on-wet
pre-wetting method. I lay down the widest tape in the box seen above, wet
it out with just barely enough epoxy to wet it out properly, then lay down
the medium width tape on top of it and wet it out, then the narrowest tape
on top of that and wet it out. If you keep trying to use 'barely enough'
epoxy and let it absorb into the glass tape at it's own rate (don't rush
it), then you'll get an optimal layup right in the pre-wetting box. Roll it
up, carry it to the boat, and unroll it along the seem and massage/stroke it
into place with gloved hands, narrowest-width tape against the fillet. The
outer layers of glass naturally press the inner layers smooths and liquid
epoxy will naturally fill the edge transition areas and what not. Done.
Scrape/sand/fair the outer tape when the whole stack has cured.

Brian D


wrote in message
oups.com...
You mean your copy of West System book also says to put the largest
piece last. This is odd because this is the opposite of what I read in
the June-2004 edition of West System literature called "Fiberglass Boat
Repair & Maintenance". I have a feeling that they might have changed
their approach within the last couple years -- not sure.

As what your experience showed, we may encounter a small problem if we
put the largest piece last. We can sand away some of the largest piece
of fiberglass cloth if we don't put enough fairing compound to protect
the fiberglass cloth, and may reduce the strength of the largest
fiberglass cloth. On the other hand, if we put the smallest piece
last, we will only sand away the edge of the fiberglass cloth. I guess
that may be the reason why West System suggest putting the smallest
piece last. I guess I will stick with the approach that West System
has suggested.

Anyway, as what you have said, this probably doesn't matter much.
Either approach will be fine if we put enough fairing compound to
protect the fiberglass cloth.

Thanks for sharing your experience.

Jay Chan

derbyrm wrote:
On my first boat (a stitch and glue dinghy), I carefully read both the
Gougeon Brothers and System Three's directions and put the small tape
down
first with the larger on top. I did not put on sufficient fairing
compound,
so when I sanded, the wider tape was quickly cut down by the ridge at the
selvedge edge of the narrower layer. Since then I've been putting the
narrow tape on top. I really don't think it matters much.

Roger

http://home.insightbb.com/~derbyrm

"Ron Magen" wrote in message
news:t0Fmg.515$uo.477@trnddc07...
Jay,
I would re-read BOTH the Gudgeon Brothers literature and Don Casey's
book
.
. . carefully.

There are subtle differences between repairing a hole from the OUTSIDE,
or
from the INSIDE. It also depends on whether you are 'laying up' or
'repairing'. It sounds to me that you are looking at the the
instructions
on
pgs. 63 - 67, and the illustrations on pg. 65.

If you will note, the bottom sketch shows the ' . . .alternating layers
of
MAT and CLOTH.}. This is an exaggerated detail of the bevel that is all
around the repair It is a type of 'scarf joint' to give you the
strongest
connection between the 'skin' over the repaired / replaced core and the
remainder of the decking. If you are talking about STRUCTURAL
strength -
that depends on the repair you did on the core. When 'mat' is
mentioned,
it
indicates that there is some substantial thickness involved. Also, the
last
layer should be cloth. {followed by a couple of coats of Gelcoat or
some
other topcoating}

Regards & Good Luck,
Ron Magen
Backyard Boatshop

wrote in message
ups.com...
I would like to know the right way to lay down layers of fiberglass
clothes over a tapered edge of a fiberglass skin of a deck. Should I
lay down the largest piece first or the smallest piece of fiberglass
cloth first?

The balsa of the cored deck was rotten, and I needed to cut out the
outer skin of the deck (the outer skin was destroyed during the
process), removed the rotten core with good one. When I finally put
good core back in place, I will need to use epoxy and layers of
fiberglass cloths to replace the outerskin of the deck. I am supposed
to grind the edge of the sounding fiberglass skin into a tapered edge,
and then attach the edge of the fiberglass cloths over the tapered
edge
of the surrounding fiberglass skin.

The question is: Should I put the largest piece of fiberglass cloth
first and the smallest piece last like what West System has suggested?
Or should I put the smallest piece first and the largest piece last
like what Don Casey (author of "This Old Boat") has suggested?

I don't care which way "looks" best; all I care is which way can give
me the strongest deck.

Which way is the right way to me?

Thanks in advance for any info.

Jay Chan

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

But dripping all over the place is part of the process???? Just try to move
all the expensive tools (planers, belt sanders, etc.) out of the line of
fire.

Roger

http://home.insightbb.com/~derbyrm
wrote in message
oups.com...

snip
I don't trust myself not to drip all over the place while I
carry the pre-wetted piece to the boat.

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

If you are dripping all over the place, then you aren't doing it right. The
glass is supposed to have the weave wetted out, but the weave should still
be quite visible... not dry looking, but dang close. You can apply fill
coats later, after it's cured into the boat. Believe me, the glass has
plenty of epoxy in it when it looks like this. No drips!

Brian


"derbyrm" wrote in message
m...
But dripping all over the place is part of the process???? Just try to
move all the expensive tools (planers, belt sanders, etc.) out of the line
of fire.

Roger

http://home.insightbb.com/~derbyrm
wrote in message
oups.com...

snip
I don't trust myself not to drip all over the place while I
carry the pre-wetted piece to the boat.

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

The following is a RESEND (apparently the picture attachment didn't work
....anybody that wants to see the illustration can email me for it at
briandixon7 AT comcast DOT net)::
-------------------
Wet-on-wet, smallest piece first, results in underlying edges being 'pressed
down' or naturally tapered while wet, and the space near the edges will
naturally fill with liquid epoxy. Since a picture is worth a thousand
words, see the attached image which shows the areas that must be filled in
order to prevent bubbles and to ensure good load transfer from panel to
panel (marked in red.) Wet-on-wet, smallest piece first, takes care of
these areas automatically. If you go largest piece first, you still have to
fair-in (that means scrape, sand, fill, sand.) along the edges ...or should
anyway. I doubt the boat will break either way (grinz.)

Brian D

"Brian D" wrote in message
. ..

If you are dripping all over the place, then you aren't doing it right.
The glass is supposed to have the weave wetted out, but the weave should
still be quite visible... not dry looking, but dang close. You can apply
fill coats later, after it's cured into the boat. Believe me, the glass
has plenty of epoxy in it when it looks like this. No drips!

Brian


"derbyrm" wrote in message
m...
But dripping all over the place is part of the process???? Just try to
move all the expensive tools (planers, belt sanders, etc.) out of the
line of fire.

Roger

http://home.insightbb.com/~derbyrm
wrote in message
oups.com...

snip
I don't trust myself not to drip all over the place while I
carry the pre-wetted piece to the boat.

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

Actually, I'm not even using the "off-boat wetted out glass" scheme at the
moment.

All I know is that the epoxy drips end up on many things (like clothing)
that weren't supposed to be wetted. Many come from the epoxy cup where I've
wiped the brush and the stuff has climbed over the edge, run down the side,
and ... Then there's the issue of where to park the swizzle stick and/or
squeegee between uses.

Roger

http://home.insightbb.com/~derbyrm

"Brian D" wrote in message
. ..

If you are dripping all over the place, then you aren't doing it right.
The glass is supposed to have the weave wetted out, but the weave should
still be quite visible... not dry looking, but dang close. You can apply
fill coats later, after it's cured into the boat. Believe me, the glass
has plenty of epoxy in it when it looks like this. No drips!

Brian


"derbyrm" wrote in message
m...
But dripping all over the place is part of the process???? Just try to
move all the expensive tools (planers, belt sanders, etc.) out of the
line of fire.

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

I don't think that I've ever gotten a drip of epoxy falling off a pre-wetted
chunk of fiberglass tape. Of course, by the time I started using that
method, I'd gained enough glassing experience to know how much resin to put
into it, but really ...the glass holds the epoxy quite well. Try it
sometime 'cuz I think you'll like it.

And isn't the concern over a drip here and there a bit like being concerned
about getting wet when you go fishing? Be careful, but don't sweat the
occasional drips and runs. Buy a 3" wide carbide scraper (with handle, and
a knob above the business end) and the SurForm tool with the short handle
and 2" by 1-1/2" (approx) curved cheese-grater on the end and you'll no
longer sweat the little accidents ...they come off easily after curing and
it's easy to leave a smooooth finish behind. Home Despot has these things
for cheap and no epoxy user should be without them. Forget sandpaper for
fixing drips and runs ...bad idea. Relax and enjoy the build.

Enjoy!

Brian D



"derbyrm" wrote in message
m...
Actually, I'm not even using the "off-boat wetted out glass" scheme at the
moment.

All I know is that the epoxy drips end up on many things (like clothing)
that weren't supposed to be wetted. Many come from the epoxy cup where
I've wiped the brush and the stuff has climbed over the edge, run down the
side, and ... Then there's the issue of where to park the swizzle stick
and/or squeegee between uses.

Roger

http://home.insightbb.com/~derbyrm

"Brian D" wrote in message
. ..

If you are dripping all over the place, then you aren't doing it right.
The glass is supposed to have the weave wetted out, but the weave should
still be quite visible... not dry looking, but dang close. You can apply
fill coats later, after it's cured into the boat. Believe me, the glass
has plenty of epoxy in it when it looks like this. No drips!

Brian


"derbyrm" wrote in message
m...
But dripping all over the place is part of the process???? Just try to
move all the expensive tools (planers, belt sanders, etc.) out of the
line of fire.

Largest Piece Or Smallest Piece First When Laying FiberglassCloth Over a Tapered Edge?
 

Brian D wrote:
I don't think that I've ever gotten a drip of epoxy falling off a pre-wetted
chunk of fiberglass tape. Of course, by the time I started using that
method, I'd gained enough glassing experience to know how much resin to put
into it, but really ...the glass holds the epoxy quite well. Try it
sometime 'cuz I think you'll like it.


Another good way to pre-wet-out pieces of cloth is to use
PVC sheet. It's commonly sold in varying thickness as
painter's dropcloth. The .5 mil stuff is kinda flimsy but
can be molded around 3-D shapes pretty well, the 3 mil stuff
is pretty strong and I use it for wetting out pre-cut pieces
on a flat bench or floor. It can be re-used almost
infinitely too. Cured epoxy will not stick to it, makes a
great barrier film.

My method is to get a piece of the plastic sheeting that's
at least twice as big as the fiberglass cloth I'm
laminating, lay the cloth into one half of it, then add some
mixed resin. Fold the other half of the sheet over, then
roller it so that the resin gets spread eavenly thru the
cloth and you don't get ick all over your hands or the
roller. You can really get a great resin-glass ratio and
handle the piece without fear of runs or drips.


And isn't the concern over a drip here and there a bit like being concerned
about getting wet when you go fishing? Be careful, but don't sweat the
occasional drips and runs. Buy a 3" wide carbide scraper (with handle, and
a knob above the business end) and the SurForm tool with the short handle
and 2" by 1-1/2" (approx) curved cheese-grater on the end and you'll no
longer sweat the little accidents ...they come off easily after curing and
it's easy to leave a smooooth finish behind. Home Despot has these things
for cheap and no epoxy user should be without them. Forget sandpaper for
fixing drips and runs ...bad idea. Relax and enjoy the build.


Or get a plastic putty knife and scrape up the dripping /
running resin, take it over to your wet-out work area, and
re-use it on the next piece of cloth. Economical and saves
clean-up time.

I've seen a heck of a lot of people working in fiberglass
who seem to bring an unshakeable woodworker's mentality to
the process.... make it thick, then cut it or sand it...
then add some more and sand it off... etc etc. Shucks, the
beauty of molding composites is that you can make it any
shape you want, in less time, and make it *strong*. Get the
material to work for you, not against you.

Not that I'm an expert or anything, but I've made a lot of
stuff out of epoxy resin added to various other materials...
including carbon fiber... over the years.

Fresh Breezes- Doug King

Largest Piece Or Smallest Piece First When Laying Fiberglass Cloth Over a Tapered Edge?
 

Some guy posted an article at http://www.duckworksmagazine.com about using
slightly-heavy clear plastic sheeting to fair a boat. If I recall, he put
the glass on the boat, then rolled the sheeting onto it, let it cure and
pulled the sheeting off. The pictures that I saw were marvelous ...glossy
smooth with no imperfections, no boundary marks or lines near edges of
overlapped cloth or at scarfs or anything. Never did give it a try myself
though, but it looked like it worked for him.

I did recently cut off the curved top of a transom to make it flat so I
could run a tuna handline behind the boat (tied to a handline cleat) without
the line rubbing on the transom. It's impossible to get a perfectly
straight cut and all I did to tune it up was to put a thin layer of
microballoon mix + epoxy on it, lay plastic wrap over it, then used a piece
of aluminum angle stock to press the top flat. Came out beautiful. Ready
to fair it in and paint....

Brian D



"DSK" wrote in message
...
Brian D wrote:
I don't think that I've ever gotten a drip of epoxy falling off a
pre-wetted chunk of fiberglass tape. Of course, by the time I started
using that method, I'd gained enough glassing experience to know how much
resin to put into it, but really ...the glass holds the epoxy quite well.
Try it sometime 'cuz I think you'll like it.


Another good way to pre-wet-out pieces of cloth is to use PVC sheet. It's
commonly sold in varying thickness as painter's dropcloth. The .5 mil
stuff is kinda flimsy but can be molded around 3-D shapes pretty well, the
3 mil stuff is pretty strong and I use it for wetting out pre-cut pieces
on a flat bench or floor. It can be re-used almost infinitely too. Cured
epoxy will not stick to it, makes a great barrier film.

My method is to get a piece of the plastic sheeting that's at least twice
as big as the fiberglass cloth I'm laminating, lay the cloth into one half
of it, then add some mixed resin. Fold the other half of the sheet over,
then roller it so that the resin gets spread eavenly thru the cloth and
you don't get ick all over your hands or the roller. You can really get a
great resin-glass ratio and handle the piece without fear of runs or
drips.


And isn't the concern over a drip here and there a bit like being
concerned about getting wet when you go fishing? Be careful, but don't
sweat the occasional drips and runs. Buy a 3" wide carbide scraper (with
handle, and a knob above the business end) and the SurForm tool with the
short handle and 2" by 1-1/2" (approx) curved cheese-grater on the end
and you'll no longer sweat the little accidents ...they come off easily
after curing and it's easy to leave a smooooth finish behind. Home
Despot has these things for cheap and no epoxy user should be without
them. Forget sandpaper for fixing drips and runs ...bad idea. Relax and
enjoy the build.


Or get a plastic putty knife and scrape up the dripping / running resin,
take it over to your wet-out work area, and re-use it on the next piece of
cloth. Economical and saves clean-up time.

I've seen a heck of a lot of people working in fiberglass who seem to
bring an unshakeable woodworker's mentality to the process.... make it
thick, then cut it or sand it... then add some more and sand it off... etc
etc. Shucks, the beauty of molding composites is that you can make it any
shape you want, in less time, and make it *strong*. Get the material to
work for you, not against you.

Not that I'm an expert or anything, but I've made a lot of stuff out of
epoxy resin added to various other materials... including carbon fiber...
over the years.

Fresh Breezes- Doug King