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.

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.

On Fri, 05 Mar 2010 11:35:22 -0500, Paul Oman
wrote in rec.boats.building:

if you clamp too tightly you will squeeze the epoxy out and the joint
will fail.

That's why I apply thickener. Enough pressure to achieve the bend and
the closure of any gaps, but not too much to press it all out.

My question just aims at the amount I should apply. Too much is bad,
too little too.

Thanks for your comment!

U.

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.

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.

Epoxy is the wrong adhesive for this application. If it was the correct glue, plywood would be made this way and it isn't. As
stated by others, epoxy does not like to be thin and your application should be tightly clamped. You should be using waterproof
resorcinol for the panel lamination. It is cheaper, less messy and easier to work with. Reserve your epoxy to your structural
joints and you will be golden. Use the right tools for the right job.
Steve

"Ulrich G. Kliegis" diesemailadressevonUlliistzwaretwaslangabersieist wrote in message
...
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.

I agree with Steve, after all resorcinol is what they use to make
marine plywood and for good reason.

Timmynocky

On Mar 6, 7:26*am, "Steve Lusardi" wrote:
Epoxy is the wrong adhesive for this application. If it was the correct glue, plywood would be made this way and it isn't. As
stated by others, epoxy does not like to be thin and your application should be tightly clamped. You should be using waterproof
resorcinol for the panel lamination. It is cheaper, less messy and easier to work with. Reserve your epoxy to your structural
joints and you will be golden. Use the right tools for the right job.
Steve

"Ulrich G. Kliegis" diesemailadressevonUlliistzwaretwaslangabersieist wrote in messagenews:efb2p5t1fiuqf72g6h0im2eeb6u2a40oan@4ax .com...



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.

timmynocky wrote:
I agree with Steve, after all resorcinol is what they use to make
marine plywood and for good reason.

Timmynocky

Yeah.
It's CHEAP.