Clive=0Ait probably IS due to osmosis, (imho) try puncturing a bubble, if y
ou get a dark brown=0Adrop of liquid that would be it. We have to accept th
at paint is not waterproof. =0AIf there is contamination on the surface bef
ore painting, water vapour will migrate through the paint =0Aby nudging a w
ater molecule off the end of a long chain molecule. One -OH will attach at
the surface and =0Aone will drop off the other end to dissolve the offendin
g contamination.The comtaminant signals via the =0Achain molecule that it w
ants water and osmosis does the rest.=0ASome waterproof breathable cloth is
made this way, like Goretex but at a molecular level. =0AIn that sutuation
body heat creates the vapour inside the garment which drives the water out
where it condenses=0Aand goes away with the rain. This is why Goretex is n
o good on a hot day, heat drives the water inwards.=0Abtw I won't argue wit
h Roger but I will discuss with him.=0AGraham=0A=0A=0A=0A=0A=0A=0A_________
_______________________=0A From: gtagr <clive.maf@googlemail.com>=0ATo: eur
opa-list@matronics.com =0ASent: Friday, 1 November 2013, 14:06=0ASubject: E
uropa-List: Re: Europa Classic wing blistering=0A =0A=0A--> Europa-List mes
sage posted by: "gtagr" <clive.maf@googlemail.com>=0A=0AHi Gordon, I have a
similar problem and I' assured by Roger Targett that it is not uncommon on
glass a/c and on many gliders.- The problem is apparently related to moi
sture (perhaps from humidity levels at the time of surface preparation) bei
ng sealed under the surface at the time of painting.- So the remedy would
seem to be re-finishing of the affected areas - which I'm considering.-
It is NOT due (as I've seen some assert) to osmosis - which is seen in fibe
glass boats where surfaces are under constant pressure and contact with wat
er and in part due to the peculiarities of the resins systems used in boats
(see previous post by Nev).- Its cosmetic, but unsightly and probably an
other =C2=A31000-to-fix job . . .=0AClive.=0A=0A=0A=0A=0ARead this topic on
line here:=0A=0Ahttp://forums.matronics.com/viewtopic.php?p=411913#411913
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