Great Planes PT-40 MkII Kit - GPMA0118 - Manual (Page 8)

Accelerator is a liquid chemical for
use in speeding up the cure time of
all CA types. It should be misted on,
not sprayed heavily on the joint. A
typical use of accelerator is to spray
a light mist on a fillet of thick or
medium CA to prevent it from running
or dripping. Another use of accelerator
is to “prime” one of the parts you are
joining before you apply the CA, then
add thick or medium CA to the part
that has not been primed. The CA will
cure immediately when the parts
contact each other, so be careful as
this leaves no time for positioning.
There are special instances where this method comes in
handy but we do not suggest you build your entire model in
this manner. Sometimes, when you glue a joint with thin
CA, the CA is so thin that it is drawn deep into the wood
and away from the glue joint. This can be prevented by first
priming the joint with accelerator, then adding thin CA. The
CA will cure “on the spot” before it has a chance to be
drawn away from the joint.
During the later stages of construction be aware of areas
that you may have sprayed with accelerator. Often times,
residual accelerator, even if sprayed on hours before, may
cause the CA on a nearby joint to cure prematurely and
unexpectedly – it's pretty potent stuff!
Overuse of accelerator may cause CA to bubble and
sometimes change color. A drawback to accelerator can be
that the CA cures before it has time to fully penetrate the
wood, so it should only be used sparingly – only when
necessary. For future reference, keep accelerator away
from clear canopies and other plastic parts such as cowls
and wheel pants. Accelerator will “fog” the butyrate plastic
that most canopies are made from and can cause the ABS
plastic that many cowls are made from to soften.
Epoxy
Great Planes has several Epoxy formulations available for
the modeler. The two most often used epoxies are 6-minute
and 30-minute. Both offer exceptional strength and good
working times. We recommend that you use epoxy when
the joint requires exceptional strength, such as when
installing the firewall, when joining the wing panels and
when installing wing hold-down blocks. As with most
epoxies, you mix equal parts of resin and hardener, stir
well, then apply a thin film to each part. Parts should be
clamped, pinned, taped or weighted in place until fully
cured. Before the epoxy cures, clean off any excess with a
paper towel. A word of caution about mixing epoxy – don't
use extra hardener in the hopes of making the mixture
harder or work faster. Just about all epoxies work best with
exactly a 50/50 mixture. When you increase the amount of
hardener you run the risk of causing the cured epoxy to
become either brittle or rubbery – neither being as strong as
a properly mixed batch.
A word about safety!
After applying CA, step back or look away from the work
to avoid the puff of vapors. All CA glues will bond skin
almost immediately. If this should happen, CA Debonder
(available from your hobby dealer) or acetone fingernail
polish remover will dissolve the CA if allowed to soak
into the bond for a few minutes. Don't use vigorous
means to separate a skin bond. Never point the CA
applicator tip toward your face and be especially careful
when opening a clogged tip. In case of eye contact,
flush thoroughly with water, then seek medical attention,
but don't panic. Please, keep CA (and all other
modeling chemicals) out of the reach of children.
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Metric Conversion