> -----Original Message-----
> Subject: RE: Peel Ply
>
>
>
> Amine blush is only on the surface. If one uses Peel Ply then the
> amine blush is on the peel ply layer. Off with the ply...off with
> the blush.
>
> Regarding solvents. I'm not sure what the right answer is. MEK
> and acetone will dissolve styrofoam. Alcohol doesnt seem to in my
> informal dunk tests. I was considering using dishwashing soap but
> was concerned about the additives for softening hands. is this a
> concern? If so Which soap is safest?
>
> Sheldon M.
>
> > -----Original Message-----
> > From: owner-europa@post.aviators.net
> > Subject: Re: Peel Ply
> >
> >
> > Miles McCallum wrote:
> > >
> > > > My inspector insists I peel-ply everything. That gives a
> surface free
> > > > of amine blush that can be readily abraded to key
> whatever's going on
> > > > next, without cutting into the glass.
> > >
> > > Amine blush is a function of excess or unmixed hardener - it'll
> > appear on
> > > peelplied surfaces just as easily - if the peel ply is off.
> > >
> >
> > Miles, I 'googled' several mfr's user manuals and tech papers re epoxy
> > laminating resins, and they say amine blush is oily/waxy/cloudy and a
> > result of the curing chemistry, aggravated by high ambient moisture,
> > and varies by product. It is removed with water, cut with some
> > ammonia. It will be harder to remove if peel ply is used, and they
> > say _do not_ apply resin or adhesive over any blush. The residue you
> > describe as due to improper mix they say just condemns the layup, if
> > not gone in couple days.
> >
> > Some thus say their product don't blush, and FWIW, I have never seen
> > any with the Aeropoxy supplied to builders here. Sometimes it isn't
> > just sales brochure puffery, I guess.
> >
> > Also re the use of solvents, there's no worry it seems for wax/oil/etc
> > removal. Chemically pure (CP), or virgin, MEK (unhealthy), lacquer
> > thinner, or acetone are specified in the docs. And in the States
> > here, if the can don't say CP or virgin, it is probably 'recovered'
> > and thus contaminated. MEK is used as test for improperly cured or
> > mixed resin, and they use a numeric scale (MEK Resistance) in
> > specifying solvent resistance. A technical doc published the the
> > Australian Air Force re composite repairs requires cleaning with MEK,
> > abrasion, then MEK again to remove the dust. I prep'd all my bonding
> > surfaces that way in mere ignorance. Feel much better now....
> >
> > One more epoxy factoid. Water(!) can actually weaken epoxy. Not by
> > dissolution but osmosis, if soaked. Thus, epoxy for boat building
> > below the water line is formulated to prevent that.
> >
> > Regards,
> > Fred F., A063
> >
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