Q.V.P. VAKUUM BAGS WITHOUT BASEBOARDS - Manual (Page 2)

Whether doing curved staircases or round top windows, the
laminates are glued up, taped, mesh is added and then put in
the bag. The bag is placed over the form and clamped to hold
it to the form. Vacuum is applied and squeezes with 1800
lbs./sq.ft. of even and uniform pressure.
Always do a dry run the first time trying something for
the first time or if you are resetting up the equipment.
Glue: For curved pieces we recommend our VAK-Bond
2000 for several reasons. It has 20 - 30 minutes of open time
and dries with a rigid glue line, thus eliminating or minimizing
spring back. A rigid glue line is developed due to the fact that
the glue cures by a chemical reaction. Most yellow and white
glues cure by the solvent migrating away from the glue joint.
Thus, if the solvent (usually water) comes in contact with the
joint, it softens and weakens. VAK-Bond 2000 has high
water and heat resistance.
After gluing and stacking the laminates, use fiberglass
reenforced tape to wrap them, however, reverse the tape.
The laminates need to slide as they are curved around the
form, thus, reversing the tape prevents sticking and they slide
freely while still being held in place by the tape. To hold joints
together, use one or two strips of the same tape across the
joint. Masking tape will break and not hold.
Wrap the laminates in a mesh (plastic window screen is OK).
It should cover at least the side where the VCA is located.
The mesh acts as channels for the air to get out of the far end
of the bag. If the head of the VCA hits the outer laminate, and
not the mesh, it will seal itself off and the bag will not develop
the full 1800 lbs./sq.ft. of pressure. Apply some tape to hold
the mesh in place. Sometimes it helps if you draw a slight
vacuum on the bag before placing it on the form.
Consider using a female form when doing small radius
arches like window jambs. When the bag is bent around the
male side of the form,
notice that the bag will have small
ripples on the inside of the arch. On larger radii, this fraction
of an inch of ripple is normally not a problem. On a small
radius, this could be a problem, thus using the inside of the
form will solve this problem.
the bag on the topside of the arch will
be smooth, however,
TIPS WHEN PRESSING WITH FORMS
OUTSIDE THE VACUUM BAG.
Visit our web site www.qualityvak.com and
view the Q.V.P. Newsletter section to view
Techniques #1 for further instruction.