On Sep 19, 7:07 am, Brian Nystrom wrote:
wrote:
On my wood Tolman Skiff, I have found a couple of places where two
layers of wood epoxied together are delaminationg. Nothing serious
but if left unfixed would lead to problems. Basically, the directions
said to paint all surfaces with thin epoxy and then before it cured to
spread the thicker and then to join the pieces. So, how am I getting
delamination?
I live in Florida so it is subject to extreme humidity and heat.

I think you may have misinterpreted the directions. For laminating, you
need to coat both surfaces with epoxy and allow it to soak into the
wood. You may need to apply more to areas that are particularly
absorbent. Once the surface is sealed, you need to thicken a batch of
epoxy with silica, wood flour, microballoons, etc. and spread that over
the surfaces to be laminated. Clamp the surfaces lightly and allow it to
cure. The purpose of the thickener and light clamping is to prevent the
epoxy from being squeezed out of the joint.

This is West System epoxy and when I mean thinned I mean I simply have
not added thickener like microballoons or microfiber. I did not add
thinner. The epoxy straight from the pumps is mixed and painteed on
the bare wood and allowed to soak in, Then microfiber is then added
to thicken it and strengthen the joint, smeared on evenly and the two
parts are then joined with screws to hold them together. small
amounts of delamination has occurred at two joints that were not
covered with glass

writes:

This is West System epoxy and when I mean thinned I mean I simply have
not added thickener like microballoons or microfiber. I did not add
thinner. The epoxy straight from the pumps is mixed and painteed on
the bare wood and allowed to soak in, Then microfiber is then added
to thicken it and strengthen the joint, smeared on evenly and the two
parts are then joined with screws to hold them together. small
amounts of delamination has occurred at two joints that were not
covered with glass

You may have told us already but sometimes my memory is short:
How old is this lamination?

--
Martin Schöön "Problems worthy of attack
show their worth by hitting back."
Piet Hein

On Fri, 19 Sep 2008 07:30:15 -0700 (PDT),
wrote:

On Sep 19, 7:07 am, Brian Nystrom wrote:
wrote:
On my wood Tolman Skiff, I have found a couple of places where two
layers of wood epoxied together are delaminationg. Nothing serious
some snipped

This is West System epoxy and when I mean thinned I mean I simply have
not added thickener like microballoons or microfiber. I did not add
thinner. The epoxy straight from the pumps is mixed and painteed on
the bare wood and allowed to soak in, Then microfiber is then added
to thicken it and strengthen the joint, smeared on evenly and the two
parts are then joined with screws to hold them together. small
amounts of delamination has occurred at two joints that were not
covered with glass

I'm not sniping just gathering information.

Are you saying that the actual glued joint has failed or partially
failed? I'm a bit confused by the word "delaminated".

If the epoxy glue failed but the joint has screws holding it together
how do you know it has failed? Is there movement in the joint now that
wasn't there originally?

I ask as I build stitch and glue dinghys that have no fasteners.
Several are ten years old and exhibit no problems so far and I have
always considered epoxy to be pretty much a life time glue. However,
if someone else is having problems I certainly want to know as I don't
want to sell a dinghy and have it fall in pieces. (don't want my own
to either :-)


Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

Bruce in Bangkok writes:

I ask as I build stitch and glue dinghys that have no fasteners.
Several are ten years old and exhibit no problems so far and I have
always considered epoxy to be pretty much a life time glue. However,
if someone else is having problems I certainly want to know as I don't
want to sell a dinghy and have it fall in pieces. (don't want my own
to either :-)

And my boat has seen 22 sailing season so far. No fasteners, just epoxy.
Problems I have had so far have been due to either UV-degradation or
errors in my workmanship.

http://hem.bredband.net/b262106/

--
Martin Schöön "Problems worthy of attack
show their worth by hitting back."
Piet Hein

wrote:

On Fri, 19 Sep 2008 07:30:15 -0700 (PDT),
wrote:


On Sep 19, 7:07 am, Brian Nystrom wrote:

wrote:

On my wood Tolman Skiff, I have found a couple of places where two
layers of wood epoxied together are delaminationg. Nothing serious
but if left unfixed would lead to problems. Basically, the directions
said to paint all surfaces with thin epoxy and then before it cured to
spread the thicker and then to join the pieces. So, how am I getting
delamination?
I live in Florida so it is subject to extreme humidity and heat.

I think you may have misinterpreted the directions. For laminating, you
need to coat both surfaces with epoxy and allow it to soak into the
wood. You may need to apply more to areas that are particularly
absorbent. Once the surface is sealed, you need to thicken a batch of
epoxy with silica, wood flour, microballoons, etc. and spread that over
the surfaces to be laminated. Clamp the surfaces lightly and allow it to
cure. The purpose of the thickener and light clamping is to prevent the
epoxy from being squeezed out of the joint.

This is West System epoxy and when I mean thinned I mean I simply have
not added thickener like microballoons or microfiber. I did not add
thinner. The epoxy straight from the pumps is mixed and painteed on
the bare wood and allowed to soak in, Then microfiber is then added
to thicken it and strengthen the joint, smeared on evenly and the two
parts are then joined with screws to hold them together. small
amounts of delamination has occurred at two joints that were not
covered with glass


The wood may have been contaminated in those spots. The epoxy may not
have been completely mixed, you may have used fast hardener rather
than the proper slow hardenener. Then there is the issue of UV
exposure.

Lot of things can go wrong. Most of them are easy to avoid with a
little care.



And, in the end, it's the glass that makes a water resistant barrier.
No glass, huh?



--

Richard

(remove the X to email)