Any comment if Epoxy over Polyester will work?

My news wrote:
Any comment if Epoxy over Polyester will work?

No problem if the polyester is *well* cured. Months or years not weeks.
Abrade surface thoroughly first.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:

On Thu, 01 Jan 2009 21:49:40 +0000, IanM
wrote:

My news wrote:
Any comment if Epoxy over Polyester will work?

No problem if the polyester is *well* cured. Months or years not weeks.
Abrade surface thoroughly first.

Also make sure you de-wax the surface before sanding.

On Fri, 02 Jan 2009 01:59:20 GMT, Dan@ (Pirateer guy) wrote:

On Thu, 01 Jan 2009 21:49:40 +0000, IanM
wrote:

My news wrote:
Any comment if Epoxy over Polyester will work?

No problem if the polyester is *well* cured. Months or years not weeks.
Abrade surface thoroughly first.

Also make sure you de-wax the surface before sanding.
Ummm what wax?

On 2 Jan 2009 20:54:02 -0600, nothermark wrote:

On Fri, 02 Jan 2009 01:59:20 GMT, Dan@ (Pirateer guy) wrote:

On Thu, 01 Jan 2009 21:49:40 +0000, IanM
wrote:

My news wrote:
Any comment if Epoxy over Polyester will work?

No problem if the polyester is *well* cured. Months or years not weeks.
Abrade surface thoroughly first.

Also make sure you de-wax the surface before sanding.
Ummm what wax?

Polyester uses a free radical cure with the reactive diluent styrene.
Oxygen activates the inhibitor, so a wax is incorporated into the
resin-styrene solution. The wax migrates to the surface during cure
to prevent oxygen exposure and allow complete cure. Otherwise, the
stuff won't cure on the surface. You need to remove this residual wax
as it'll prevent adhesion of the epoxy.

Pete Keillor

On Fri, 02 Jan 2009 22:14:36 -0500, Pete Keillor
wrote:

On 2 Jan 2009 20:54:02 -0600, nothermark wrote:

On Fri, 02 Jan 2009 01:59:20 GMT, Dan@ (Pirateer guy) wrote:

On Thu, 01 Jan 2009 21:49:40 +0000, IanM
wrote:

My news wrote:
Any comment if Epoxy over Polyester will work?

No problem if the polyester is *well* cured. Months or years not weeks.
Abrade surface thoroughly first.

Also make sure you de-wax the surface before sanding.
Ummm what wax?

Polyester uses a free radical cure with the reactive diluent styrene.
Oxygen activates the inhibitor, so a wax is incorporated into the
resin-styrene solution. The wax migrates to the surface during cure
to prevent oxygen exposure and allow complete cure. Otherwise, the
stuff won't cure on the surface. You need to remove this residual wax
as it'll prevent adhesion of the epoxy.

Pete Keillor

But won't sanding take care of that?

Polyester uses a free radical cure with the reactive diluent styrene.
Oxygen activates the inhibitor, so a wax is incorporated into the
resin-styrene solution. The wax migrates to the surface during cure
to prevent oxygen exposure and allow complete cure. Otherwise, the
stuff won't cure on the surface. You need to remove this residual wax
as it'll prevent adhesion of the epoxy.

Pete Keillor
Well-said Pete. I don't think sanding will every remove all of it.
Sanding could possibly just keep spreading it around. Use a wax
remover and don' look back.

"Quote from Awlgrip web site"

Awlprep Plus Wax & Grease Remover is used to remove wax residue and
grease from substrates. A medium-fast evaporating, strong, solvent
designed to remove waxes, oils, and greases commonly found on painted
surfaces, new or aged gelcoat, aluminum, or steel. Use before and
after sanding the substrate prior to priming. Always dewax before
sanding. Do not use on freshly applied primers or topcoats. It is
photochemically reactive.

On Thu, 1 Jan 2009 13:25:56 -0800, "My news" wrote:

Any comment if Epoxy over Polyester will work?

The preferred method of repairing damage to polyester boats.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Per My news:
Any comment if Epoxy over Polyester will work?

I did it when replacing the fiberglass tape that covered the
deck/hull seam on a surf ski that was over 5 years old - maybe
closer to 10.

Seemed tb holding up a-ok when I finally got rid of the ski.
--
PeteCresswell