Largest Piece Or Smallest Piece First When Laying Fibergla..

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

> 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
>
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

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.

I don't know which West System literature that you are referring to
because I cannot find the examples that you have mentioned in the West
System books that I have. The one that I read the most often is called
"Fiberglass Boat Repair & Maintenance" (around 86 pages) (June 2004
Edition). They use the "largest one first / smallest one last"
approach consistantly through out the whole literature. Examples:
- To stiffen the floor and stringers (p. 17 18, and 20)
- To repair hull from the outside (p. 25 and 27)
- To re-attach outer skin to the deck from above (p. 33)
- To re-attach outer skin to the transom from outside (p. 37)
- To lay up a new outer skin to the transom from outside (p. 3

That's just the opposition to the approach that I see in Don Casey's
book.

I figure that either approach is probably fine.

Jay Chan

Ron Magen wrote:
> 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
>
> > 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
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

If you go from the smallest piece first you have a chance of trapping
concentric rings or squares of bubbles in the laminate. Sam
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

This message is not archived
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

Can you explain a bit more on your observation of this problem? I
don't quite follow you.

Thanks.

Jay Chan


Sam wrote:
> If you go from the smallest piece first you have a chance of trapping
> concentric rings or squares of bubbles in the laminate. Sam
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

On 2006-06-24 03:26:42 -0400, ray lunder said:

> 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).

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. If
the core is not bonded to the repaired area, you have effectively
created a section that is pre-delaminated. DUH.
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

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
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

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

> 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
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

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
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

Thanks for the advice especially about leaving enough space for a layer
of fairing compounding.

Jay Chan

Ron Magen wrote:
> 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
>
> > 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
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

In general,

In hand laid structures, edges and seams should be buried.
(the deeper the better)

The components (layers) are weakest in peal loads - at the edges.
So a smaller layer on top of a larger one might be expected to peal off?

All that takes is breaking an edge loose and letting it work for a while.



YMMV

Richard
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

(corrected to bottom posting to preserve teh thread)

>>If you go from the smallest piece first you have a chance of trapping
>>concentric rings or squares of bubbles in the laminate. Sam
>
>
wrote:

> Can you explain a bit more on your observation of this problem? I
> don't quite follow you.
>
> Thanks.
>
> Jay Chan
>

You need to try it to see for yourself.

Bubbles are bad.

The are air spaces inside the laminate.

Not good for dimensional stability - or strength
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla.. 

DSK and Brian gave me a weird idea...

Those white plastic shrink-on covers on the new boats..

I wonder if that stuff would be stiff enough to lay-up a glass hull?
Strong back and transom and shrink wrapped hull form?


Might be a cheap way to lay up a hull?

Richard
 >> Stay informed about: Largest Piece Or Smallest Piece First When Laying Fibergla..