I was reading through some of the Rod
Maker Tips on your website, and had some
information that other readers might find
useful. One of the comments on the site was
from a man having trouble with 2 part flex coat
epoxy curing, and also a white hazyness.
A tacky finish is almost surely caused by
not thoroughly mixing the two parts (Resin
and Hardener), or inaccuractely measuring
the two parts. It is crucial that a 1 to 1
ratio of hardener and resin be measured to
achieve a proper curing.
Your guide wraps can be recoated with a fresh
batch of epoxy and it will cure out the tacky
coating. If you are concerned about getting a
high build up then you will need to remove the
tacky epoxy and then recoat.
The white hazyness the man is experiencing is
called Polyamine Blush.The two parts, resin and
hardener, parts A and B, contain molecules called
'amines'.
When mixing the resin and hardener the amines
in the hardener are looking for an amine molecule
of resin to bond with. A blush problem comes
from not mixing the two parts as thoroughly
as possible, epoxy curing in a cold temperature,
and/or exposure to moisture in the air during
cure. After the curing reaction has taken place
there are amine molecules that do not bind and
rise to the surface appearing as a greasy, waxy
layer. On contact with high humidity or water,
this coating turns into an opaque white smudge,
which turns into dry chalky powder with time.
You need to clean off this haze (by sanding
with ~220 grit paper) before recoating to
get a good bond between coats.
I recommend using syringes as the measuring
devices for finish epoxy. This helps to
accurately measure equal amounts of hardener
and resin. ~ Matt Yonkey
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