In article ,
says...

Ulrich G. Kliegis wrote:
I am building a new hatch lid from two 4mm ( ~1/6"") sheets of marine
ply. Reinformcement structures will follow. My question here is: How
much glue (epoxy resin plus cotton fibres as thickener) is the
optimum? My felt guess is 0.1 to 0.2 mm, i.e. ~1/240 to 1/120". Less
is hardly possible, more? The curvature is about 15 mm elevation in
the middle of a width of 600 mm.

Cheers, and TIA,

U.

if you clamp too tightly you will squeeze the epoxy out and the joint
will fail.
paul - progressive epoxy polymers inc.

Well, if you listen to the Old School guy I used to work with he would say, you
don't goo wood to wood. Put a layer of cloth in there and use the epoxy to fill
the glass...

Scotty

--
Can I haz Cheezeburger?

On Fri, 5 Mar 2010 12:46:35 -0500, I am Tosk
wrote in rec.boats.building:

Well, if you listen to the Old School guy I used to work with he would say, you
don't goo wood to wood. Put a layer of cloth in there and use the epoxy to fill
the glass...

An interesting thought. Never heard that before, but it looks like it
makes sense - although my work here is just a hatch lid, not an
icebreaker bow... But... Will have to think about it. And then,
wet in wet?

Thanks for that inspiring idea!

Cheers,
U.

Paint each side of dry wood with unthickened epoxy so it will be absorbed.
Wait a few minutes but don't let it cure. Then put a thin layer of
thickened epoxy and clamp just tightly enough to achieve the shape you need
and to mimimize any gaps. The thickened epoxy is just a gap filler and the
gaps are supposed to be very minor. If the gaps are too large then the
epoxy would form hard spots. I'd use fumed silica for thickener. The
thicker you make it the faster it cures - can be too fast to work with so
thicken only enough so it doesn't run and will act like a gap filler.

On Fri, 05 Mar 2010 19:30:36 GMT, Reno wrote in
rec.boats.building:

Paint each side of dry wood with unthickened epoxy so it will be absorbed.
Wait a few minutes but don't let it cure.

Reno, thanks. I made the sandwich just two hours before, and, maybe
that looked a bit unclear, I did not do such work for the first time.
But after having had some mess aroudn the workpiece after applying far
too much some time ago, another time woo little, I wanted to approach
it in a more deterministic way this time. So, I calculated the amount
of resin for a layer of 0.2mm thickness, added some 10% for the
soaking of the surfaces, and did it then exactly like you said - first
"priming" both surfaces (after carefully cleaning them)with
unthickened resin (West 105 resin, 206 hardener to achieve more pot
time), then thickened the remaining about 80% of the mixed epoxy with
cotton fibres and fillet blend fibres until the stuff had a
marmelade-like consisistence, then spread that with a piece of
hardfibre board over one surface, trying to get a pretty even
distribution. Prior, we had scaped two thick pieces of timber exactly
to the needed curvature. The two layers were put togehter after
adjusting the positions exactly, and then clamped to the templates,
using strips of thick timbers to press the layers down evenly. Almost
everywhere, the glue protruded a bit from between the layers, showing
that the pressure seemed to be distributed evenly enough.

Now the glue cures til tomorrow, then I'll use the same templates to
glue a supporting reinforcement frame.

Thanks for all your comments, and Paul, I'll try the cloth layer
method some time!

Cheers,
U.

On Sat, 06 Mar 2010 15:30:13 +0100, Ulrich G. Kliegis
diesemailadressevonUlliistzwaretwaslangabersieist
wrote in rec.boats.building:

first
"priming" both surfaces (after carefully cleaning them)with
unthickened resin

Of course not pure resin but the resin-hardener mix. Sorry for the
typos! Somebody seen my glasses?

Cheers,
U.

In article ,
diesemailadressevonUlliistzwaretwaslangabersieistt rotzdemgueltig@kliegis
..de says...

On Fri, 5 Mar 2010 12:46:35 -0500, I am Tosk
wrote in rec.boats.building:

Well, if you listen to the Old School guy I used to work with he would say, you
don't goo wood to wood. Put a layer of cloth in there and use the epoxy to fill
the glass...

An interesting thought. Never heard that before, but it looks like it
makes sense - although my work here is just a hatch lid, not an
icebreaker bow... But... Will have to think about it. And then,
wet in wet?

Thanks for that inspiring idea!

Cheers,
U.

I used to do that with Transoms of Ply Wood. I would laminate with a
layer of 6 oz cloth in between. On one work skiff, I used strips of
cloth inbetween the frame and hull along with the usual fasteners. As to
wet on wet, yes. It's much easier to draw Resin up through cloth, than
down so I usually pust most of my goo down first, then soak the cloth
into it. I have used pre-wetted strips for tack and tape, but not for
sheets, much easier to just use a squeegee with a wet work area in my
opinion.

I would put down a layer of goo with no thickener and give it a few
minutes to soak in. Then I would lay down a slightly thickened layer to
set the cloth in. Again, you only use enought thickener to keep the
stuff in place. Then paint down more thickened stuff on top of the glass
and set a pre wetted sheet of ply on top. Then I would apply either
weight or fasteners depending on the build.

Scotty

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

In article , I am Tosk wrote:

Well, if you listen to the Old School guy I used to work with he would say, you
don't goo wood to wood. Put a layer of cloth in there and use the epoxy to fill
the glass...

That sounds very sensible. I shall try and remember it.

Justin.

--
Justin C, by the sea.