Hello Graeme,
Ampreg 21 seems to crystallise much more easily than Ampreg 20. Last
year I
found that it was quite common for the resin to become thick and lumpy
when
getting towards the bottom of the tin, and sometimes it wouldn't pour at
all
' especially if none had been used for several weeks. The
manufacturer said
it could be restored by heating above 50=B0C for long enough to make
sure that
there were no crystals left, otherwise it would soon re-crystallise. An
hour was certainly sufficient. Once restored, it is fully usable without
any
reduction in shelf life. Such restoration can be repeated as necessary
problem should recur.
I have not tried warming resin that has already been mixed with
hardener, as
Nev suggests below, but I would regard this as a recovery measure to
avoid
throwing away material that would otherwise be unusable. You would also
run
an increased risk of exotherm as well as reduced pot life.
If you just want to get on with a small job you could, as an alternative
to
heating the whole tin of resin, warm enough resin in a mixing pot by
placing
it in a bowl of hot water and stirring until it is all clear. You could
then
let it cool to workshop temperature (20-25=B0 C is recommended for
composite
work) before mixing with hardener.
Good luck!
Mike
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of
neveyre@aol.co.uk
Sent: 20 March 2011 08:37
Subject: Re: Europa-List: Ampreg crytalised
Hi Graeme,
The Ampreg goes ''gritty'', bit like frog sporn, or School Dinner
semelina
even at room temp [ 17 to 20C], it needs to be warmed above that to let
the
''grit'' disperse. Then you have the problem of the pot life being
reduced..................... when warm it wets the cloth out easier, but
you
will have to mix very small batches.
I was never a fan of the Ampreg 20, the 21 is worse in every respect,
but it
is the only game in town when building under LAA control.
Nev.
-----Original Message-----
From: graeme bird <graeme@gdbmk.co.uk>
Sent: Fri, 18 Mar 2011 20:10
Subject: Europa-List: Ampreg crytalised
the main resin of my Ampreg 21 has gone slightly crystallized and I am
wondering
if its ok to use?
Its not old and its not been frozen or overheated should be in date as I
only
received it late last year.
--------
Graeme Bird
G-UMPY
Mono Classic/XS FWFD 912ULS/Warp drive FP
Build nearing completion
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