Hi all from Italy...
due to severe hydrolysis of all the originally low saturated external
mat of my 27" sailboat, I went to "scrape" it off by hands with chisel
(a very hard job!!)
I mostly removed all the mat until the first layer of cloth.
The hull is stucturally countermoulded,so the the hull itself is not
very thick,and it needs to be relaminated to the original thickness.
Asked around boatyards,skilled DIY,experts,everyone has the "right" and
valid solution :-))
I discarded polyester or vinilester due to poor adesion.
Working with epoxy, I would like to here from us some opinions about
differents approch:

1) Add two or three layer of 300 gr/sqmt biassial 45-/-45,but I know
the difficult
or the impossibility to work "overhead" due to the cloth weight.

2) Use more layers of lighter glass cloth (150 gr/sqmt).would it be an
easier job?

3) vacuum bagging, but... is it possible to do it "overhead" ? How?

4) dismanting,remove the keel,engine etc.etc. and flip the boat but I
have to do a lot of
work and not sure if the boatyards will cooperate,as they never
done it before.

Last,I have to work in outdoor enviroment.

Thanks for any suggestion.
Ciao from Roma,Italy
Marco

I am about to embark on a very similar project. I'm interested in the
answers too.

Ian

"Marco" wrote in message
oups.com...
...
Working with epoxy, I would like to here from us some opinions about
differents approch:

1) Add two or three layer of 300 gr/sqmt biassial 45-/-45,but I know
the difficult
or the impossibility to work "overhead" due to the cloth weight.

I've re-cored deck section from underneath with a heavy "roving" - that
thick real corse weave stuff. 24 oz/square yard - I'll let you do the
conversion. :-)

I used a "general purpose" epoxy (West Systems 105/205 ) - it took some
effort to get the cloth in place, but once it was up overhead, it stayed in
place on it's own. I would think that a "laminating resin" would not be as
sticky and would not work as well overhead.

My suggestion is to buy a small quantity of the cloth and experiment with it
to be sure it will work for you. If it sticks to the hull without too much
effort, you are ready to get the job done. If not, you won't have any
problem getting it off, and you can try something else.


2) Use more layers of lighter glass cloth (150 gr/sqmt).would it be an
easier job?

Don't know.

3) vacuum bagging, but... is it possible to do it "overhead" ? How?

Possible, sure. Necessary, I doubt it.

4) dismanting,remove the keel,engine etc.etc. and flip the boat but I
have to do a lot of

I don't think this is at all necessary.

Last,I have to work in outdoor enviroment.

Don't we all?

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

I'd sure like to hear more about how you do overhead glassing. The Gougeon
brothers claim it's nearly impossible.

Roger

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

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
...
"Marco" wrote in message
oups.com...
...
Working with epoxy, I would like to here from us some opinions about
differents approch:

1) Add two or three layer of 300 gr/sqmt biassial 45-/-45,but I know
the difficult
or the impossibility to work "overhead" due to the cloth weight.

I've re-cored deck section from underneath with a heavy "roving" - that
thick real corse weave stuff. 24 oz/square yard - I'll let you do the
conversion. :-)

I used a "general purpose" epoxy (West Systems 105/205 ) - it took some
effort to get the cloth in place, but once it was up overhead, it stayed
in place on it's own. I would think that a "laminating resin" would not be
as sticky and would not work as well overhead.
snip

"Evan Gatehouse" wrote:

It is not impossible to work overhead with moderate sizes of 300 gm
biaxial. I've done it a fair bit on my current project.

A few tricks:

- wet out cloth on a plastic coated horizontal table with resin

You mean plastic film to be rolled on pvc pipe together with cloth to help
the unrolling?

CUT...

Good luck. It is an ugly job but it is possible. Wash the hull down
with lots of fresh water and solvent like xylene. Then I would also
make sure the hull is covered with plastic and a dehumidifier is used
for a few weeks before starting.

The dehumidifier is already running... :-)

Thanks to everybody for the suggestions, I would thinking to wet the hull
with plain
epoxy and wait until it becomes sticky. Do you believe it will be useful or
not?

Marco

"derbyrm" wrote in message
news:jLM1g.692644$084.200461@attbi_s22...
I'd sure like to hear more about how you do overhead glassing. The
Gougeon brothers claim it's nearly impossible.

Roger

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


Awkward, but not impossible. I brushed on a good thick layer of epoxy on the
surface, then while that dripped on me, I spread out the roving, working it
into the epoxy as I went - you have to start at one end since if an edge
gets loose, it will all fall on your face. I stuck the roving in the epoxy
with my hands since I was working in tight spaces (cockpit lockers, under
the bridge deck, etc.) but one of those rollers they sell for laminating
would probably work real well. Once it was stuck into place, I worked in
enough epoxy to make sure it was wet out. Too much epoxy and it gets heavy
and falls down on top of you (again).

On an exterior surface like a hull, some duct tape to hold the top edge in
place would go a long way towards making the job a lot easier.

Smaller sections are easier, but on a hull you want large rolls - I suspect
you would have to compromise somewhere between too small and too large.

Wear protective coveralls, with a hood and face protection so you don't end
up taking a bath in the stuff. And, like any other fiberglass job, you might
want to build up your inventory of profanity before you start to avoid
repeating yourself quite as much ;-)


--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Marco wrote:
"Evan Gatehouse" wrote:


It is not impossible to work overhead with moderate sizes of 300 gm
biaxial. I've done it a fair bit on my current project.

A few tricks:

- wet out cloth on a plastic coated horizontal table with resin


You mean plastic film to be rolled on pvc pipe together with cloth to help
the unrolling?


No. Cover a table with polyethylene plastic to provide a surface that
is smooth and doesn't absorb extra resin. Any extra resin gets
absorbed by the next batch of cloth. Table can be a piece of plywood
on sawhorses next to the hull.


CUT...


Good luck. It is an ugly job but it is possible. Wash the hull down
with lots of fresh water and solvent like xylene. Then I would also
make sure the hull is covered with plastic and a dehumidifier is used
for a few weeks before starting.


The dehumidifier is already running... :-)

Thanks to everybody for the suggestions, I would thinking to wet the hull
with plain
epoxy and wait until it becomes sticky. Do you believe it will be useful or
not?

Yes, but it becomes a bit of a challenge to get on the cloth before
the epoxy passes into the gel stage. In other words, you can roll
lots of epoxy onto the hull easily but it takes significant time to
wet out the cloth and apply it. I wouldn't try to do the whole hull
in one day.

Marco

Lay out the roving/mat/whatever on sturdy polyethylene sheet.
Wet out the glass, and lift into place.

It's not as easy as it sounds.


Richard