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Re: Re - Poly Fiber Top Gloss

Subject: Re: Re - Poly Fiber Top Gloss
From: Jeremy Davey <jeremycrdavey@btinternet.com>
Date: Sun, 13 Oct 2002 12:32:34
Can anyone say _definitively_ how critical this is? For example, when doing
my flaps and ailerons, time constraints meant that I would have to do the
process as follows:

1) Day 1: Prep for layups
1) Day 2: Lay up one skin and leave to cure
2) Day 5: Trim, pull peel ply, sand peel-ply bumps and ridges, sand to taper
the skin to the other surface
3) Day 6: Scuff sand the skin at the join (a relatively quick process),
layup the other skin

I've always understood that if the peel ply is removed early, scuff sanding
restores the bonding surface. It's a pain, but if you can't finish the
trim-pull-sand-layup job in one go, it's about the only option.

Regards,
Jeremy

-----Original Message-----
From: forum-owner@europaclub.org.uk
Subject: Re:  Re - Poly Fiber Top Gloss


>I agree entirely. Its all to do with surface free energy (or surface
>tension).
>Thus, the idea of tooth adhesion is a myth (except in former Soviet states
>were it was held to be true). What abrading does (as you rightly state) is
>to increase surface area AND to energise the surface to provide enhanced
>surface free energy. The latter effect is short lived as contaminants (eg
>atmospheric water) will quickly invade the new high energy sites.

Duncan & Fred,
This is the idea behind peel ply. It also explains, which unfortunately the
manual does not!>? why it is important not to remove the peel ply until the
next bond is about to be made.
Graham



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