time between 3 layers of glass/epoxy??
 

I may have to lay up three layers of epoxy/glass. I think I remember that
one should not let 24 hours go between layers. If 24 hours goes by ( or
maybe some other relatively short time frame) then 'each layer must be
sanded, due to "waxing"...????

I think I remember that one must basically put one layer over the other an
hour's time, to keep from having to sand each time. Is this correct, or just
a fragment of my old memory??
thanks RichG

time between 3 layers of glass/epoxy??
 

If the epoxy has time to "blush", generally more than 24 hours but it
depends on the formulation, temperature and humidity, then you need to
wash it down with warm soapy water first to get off the amine. Amine is
water soluable so it does not take much effort. I use a Scotchbrite
pad. If you just sand without washing you are going to grind the amine
into the surface.

RG wrote:
I may have to lay up three layers of epoxy/glass. I think I remember that
one should not let 24 hours go between layers. If 24 hours goes by ( or
maybe some other relatively short time frame) then 'each layer must be
sanded, due to "waxing"...????

I think I remember that one must basically put one layer over the other an
hour's time, to keep from having to sand each time. Is this correct, or just
a fragment of my old memory??
thanks RichG



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
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time between 3 layers of glass/epoxy??
 

"RG" wrote in message
.. .
I may have to lay up three layers of epoxy/glass. I think I remember that
one should not let 24 hours go between layers. If 24 hours goes by ( or
maybe some other relatively short time frame) then 'each layer must be
sanded, due to "waxing"...????


The reason for this is not the amine blush ("waxing"), which has to me
removed anyway, but the possibility to create a chemical bond. If you wait
too long, the epoxy is cured completely and thus inert to new epoxy. Then
you have to sand it to create enough 'bite' for the new layer to hold. If
you apply the new coat/layer within a day (if I remember correctly,
otherwise see the mfg. spec) , the new coat will bond at molecular or
chemical level with the previous layer and thus producing a much stronger
result.

Meindert

time between 3 layers of glass/epoxy??
 

Just do it all at once. cut all the cloth and mix small batches of epoxy and
go go go go gogogogogogogo!