West epoxy - expanding under LP?
 

A year ago I moved some cockpit winches before painting the cockpit
with LP. Fiberglass boat with 3/4" ply inserts in winch areas. I
drilled out the old bolt holes to new wood and glass, filled them with
West epoxy and their easy sand additive powder - and sanded them flat.

Now they've domed up under the 2 coats of LP and the 2 part primer -
you can see where the bolt holes were/are by the circle of thin bumps.

Any ideas why the epoxy "expanded" up like this. There was lots of
time between the epoxy and the paint - several weeks.

I'm going to do additional work - so would like to rectify these bumps
- probable redrill and refill - but want to eliminate a second batch.

West epoxy - expanding under LP?
 

On Wed, 14 Apr 2004 11:12:18 -0700, BCC vaguely
proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

Just a guess from many bitter experiences. What looks "flat" in the
raw will not look flat under a smooth coat of paint. I usually either
work by feel to test flatness, or try to leave a small indentation,
and fill after the first coat as best I can. It may take a couple of
try's if you are really finicky about the result.

A year ago I moved some cockpit winches before painting the cockpit
with LP. Fiberglass boat with 3/4" ply inserts in winch areas. I
drilled out the old bolt holes to new wood and glass, filled them with
West epoxy and their easy sand additive powder - and sanded them flat.

Now they've domed up under the 2 coats of LP and the 2 part primer -
you can see where the bolt holes were/are by the circle of thin bumps.

Any ideas why the epoxy "expanded" up like this. There was lots of
time between the epoxy and the paint - several weeks.

I'm going to do additional work - so would like to rectify these bumps
- probable redrill and refill - but want to eliminate a second batch.

************************************************** **
I went on a guided tour not long ago.The guide got
us lost. He was a non-compass mentor.........sorry
.........no I'm not.

West epoxy - expanding under LP?
 

"BCC" wrote in message
...
West epoxy and their easy sand additive powder - and sanded them flat.


Are you sure that sanding addiative/filler was a West product?? It sure
sounds like Talc and if it is Talc, then it is absorbing moisture..

Talc is what is used in auto body filler.

Steve
s/v Good Intentions

West epoxy - expanding under LP?
 

WEST minifibers (or is it microfibers) contains _cotton_ fiber and this
absorbs moisture too. You must seal the sandable epoxy mix as though it
were plain wood, e.g. 2 or 3 coats of plain epoxy, then primer and paint.
Note: When I fill holes, I usually let them stay bumped up a little until
after curing, then I use a SurForm or scraper (or both) as appropriate to
bring it down flush. Sanding seems to remove material around the hole more
than it removes the filler in the hole, so I don't sand. I then coat the
whole section a couple of times (usually 3) prior to painting. Works for
me.

--
http://www.advantagecomposites.com/tongass -- My 22' Tolman Skiff project
http://www.advantagecomposites.com/catalog -- Discounted System Three
Resins products



"Steve" wrote in message
...

"BCC" wrote in message
...
West epoxy and their easy sand additive powder - and sanded them flat.


Are you sure that sanding addiative/filler was a West product?? It sure
sounds like Talc and if it is Talc, then it is absorbing moisture..

Talc is what is used in auto body filler.

Steve
s/v Good Intentions

West epoxy - expanding under LP?
 

definitely was West additive


On Wed, 14 Apr 2004 18:51:13 -0700, "Steve" wrote:


"BCC" wrote in message
.. .
West epoxy and their easy sand additive powder - and sanded them flat.


Are you sure that sanding addiative/filler was a West product?? It sure
sounds like Talc and if it is Talc, then it is absorbing moisture..

Talc is what is used in auto body filler.

Steve
s/v Good Intentions

West epoxy - expanding under LP?
 

Epoxy and Polyester have different thermal expansion (and cure) rates.
Better to fill the holes with epoxy in the bottom for adhesion (if
needed), and then fill the 'upper' part of the holes with polyester.

Most of the gelcoat repair 'artists' I know NEVER use epoxy for blemish
repair for the above reason. If you keep the repair materials
composition as close to the original base materials, usually the more
mechanically stable outcome will be the result.

West epoxy - expanding under LP?
 

perhaps the wood plugs swelled with moisture??

"BCC" wrote in message
...
definitely was West additive


On Wed, 14 Apr 2004 18:51:13 -0700, "Steve" wrote:


"BCC" wrote in message
.. .
West epoxy and their easy sand additive powder - and sanded them flat.


Are you sure that sanding addiative/filler was a West product?? It sure
sounds like Talc and if it is Talc, then it is absorbing moisture..

Talc is what is used in auto body filler.

Steve
s/v Good Intentions

West epoxy - expanding under LP?
 

there is/was no wood "plugs" - there's 3/4" marine ply that's been in
there for 26 years - and why would a ring of 6 holes expand?

turns out West says their 410 additive can expand - they now say use
only 407.



On Thu, 15 Apr 2004 19:02:02 -0400, "Scott Downey"
wrote:

perhaps the wood plugs swelled with moisture??

"BCC" wrote in message
.. .
definitely was West additive


On Wed, 14 Apr 2004 18:51:13 -0700, "Steve" wrote:


"BCC" wrote in message
.. .
West epoxy and their easy sand additive powder - and sanded them flat.


Are you sure that sanding addiative/filler was a West product?? It sure
sounds like Talc and if it is Talc, then it is absorbing moisture..

Talc is what is used in auto body filler.

Steve
s/v Good Intentions

West epoxy - expanding under LP?
 

On Thu, 15 Apr 2004 02:59:36 GMT, "Brian D"
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

Not the same solution as mine. But I agree with the idea that the
surrounds go down faster than the filler, in almost all cases.

When I fill holes, I usually let them stay bumped up a little until
after curing, then I use a SurForm or scraper (or both) as appropriate to
bring it down flush. Sanding seems to remove material around the hole more
than it removes the filler in the hole, so I don't sand. I then coat the
whole section a couple of times (usually 3) prior to painting. Works for
me.

************************************************** **
I went on a guided tour not long ago.The guide got
us lost. He was a non-compass mentor.........sorry
.........no I'm not.

West epoxy - expanding under LP?
 

On Thu, 15 Apr 2004 22:53:52 -0700, BCC vaguely
proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

there is/was no wood "plugs" - there's 3/4" marine ply that's been in
there for 26 years - and why would a ring of 6 holes expand?

turns out West says their 410 additive can expand - they now say use
only 407.

OK. I and one other posted saying that the sanding may be the problem.
OOI, can we hear back what happens with the non-expanding filler?

We may be wrong, but we tried to help.....
************************************************** **
I went on a guided tour not long ago.The guide got
us lost. He was a non-compass mentor.........sorry
.........no I'm not.