TM 1-1500-204-23-11
result in high porosity and low strength. Excessive
resin will add weight and may reduce strength slightly.
NOTE
Optimum iber volume content is 62% of the total
Ensure expiration of the shelf life marked
volume (iber plus resin); however, this is often too
on paste adhesive containers has not been
dificult to achieve in wet layups.
exceeded.
NOTE
Mixing or preparing adhesives and resins
should be done immediately prior to applica-
Do not mix several batches at once, in order
tion/use and according to the system speciic
to avoid an exotherm or exceeding pot life
technical manual. If technical manual guid-
conditions.
ance does not exist, consult the manufacture s
technical data sheets or engineering.
(a) Determine the amount of each part to
mix as follows. First, determine the
c. Preparing Two-Part Repair Materials. Two-part
amount of material required to perform
repair materials must be prepared properly before they
the repair. Next, determine the mix
can be used in the repair. Wet layup resins, adhesives,
ratio from the adhesive container or
and sealants often come in two parts: Part A contains
system speciic technical manual. Filler
the base resin and Part B contains the curing agent.
materials (such as chopped carbon
The overall amount of repair material must irst be
or glass ibers, milled glass ibers or
determined, then the amount of Part A and Part B
microspheres) may be added to the
can be calculated. Each part is then weighed out
adhesive to produce iller compounds.
in separate containers before thoroughly mixing. Too
The amount of material to be added is
little curing agent to base resin could result in low
speciied in parts by weight. Determine
mechanical properties as well as slow down the curing
the amount of each part to be added
cycle when curing at room temperature. Too much
using the following formulas in igure
curing agent to base resin can decrease the pot
6-28. Figure 6-29 is an illustration of
life, result in excessive exothermic reaction, and/or
how to calculate the required amounts
signiicantly degrade the structural properties of the
of components to mix to obtain a spe-
material.
ciic amount of material for repair.
(1) Facilities, Tools, Equipment, and Mate-
rials Required. The following items are required:
Repair material information sheet (system speciic
technical manual, vendor data, etc.), Calculator, Pen-
cil, Notepad, Worktable or workbench, Weighing scale
(grams) or triple beam balance, Mixing cups (do not
use wax coated), Latex or nitrile gloves, Two-part
resin (Part A and Part B) (See System Speciic Tech-
nical Manual), Stirring sticks, Non-porous release ilm
(2) Calculate Resin Amounts. To accurately
determine the overall amount of resin required consult
the system speciic technical manual or resin manu-
facturer s recommendations for the amount required.
If no technical data is available, mix 25 grams of
resin according to the manufacturer s instructions for
Figure 6-28. Two Part Adhesives and Filler
each square foot of dry fabric. Typically, you should
Compounds Formula
strive for the minimum amount of resin required to
completely wet out the fabric. Too little resin will
