Paste Laminating Systems
Paste Laminating
is a tooling process designed to lessen the considerable
time it takes to lay up medium-sized tool without
sacrificing strength or stability.
Those who have followed the epoxy laminating system to lay
up a dozen or more layers of fiberglass cloth have
experienced the biggest drawback of that system, which is
time. In this process, you apply a 1/2 inch thick layer of
paste laminate material, such as our Freeman 1020, between
layers of fiberglass cloth, creating a very strong, yet
lightweight tool in much less time.
This project is going to be a three-part mold with curved
parting lines. To form the parting lines, we’re
using Freeman’s 3/8 inch high temperature sheet
wax.
We’ve chosen the 266 series high temperature wax instead
of our 165 series lower temperature wax because it is
much easier to bend and flex by hand. We are adhering
the wax strips with Plast-Econ modeling clay.
After sealing the sheet wax with Freeman Wood & Plaster
Sealer, we are applying PVA and wax release to the entire
part. For proper sealing and releasing procedures, please
see our other video on this topic.
The first step of the paste laminating system involves
applying two layers of surface coat such as our
Freeman 705, with a cut brush. As
always, we wait for the material to reach the almost
tack-free state before applying additional layers.
The next step is applying three layers of laminating resin
and fiberglass cloth, much as you would in a typical epoxy
layup. Since we devote an entire video to epoxy laminating
systems, we won’t repeat those instructions here.
After three layers, you are now ready for the paste
laminate material. We are opening our packages of
Freeman 1020 on a plastic covered table.
Since each gallon kit will cover about 420 square
inches, we know this project will require more than one
gallon kit. So we begin by mixing the entire bags
together without having to weigh the material. When we
require less than one full kit of material, we will
weigh the material using 100 parts resin to 33 parts
hardener.
This material is easy to mix by hand. The goal is to mix
until the material until it reaches a uniform color.
If you mix the paste laminate material too much, it will
become very sticky, which will make it more difficult to
apply.
Next, using a rolling pin, we roll our material on a
plastic-covered piece of wood, which has been specifically
built with a half inch clearance in the middle.
With our material now rolled out to a uniform 1/2 inch
patty, we cut the material into strips for easier handling
and apply the paste to the back of our tool.
Since most projects aren’t exactly rectangular, you may
have to cut the material into smaller pieces to fit into
small corners and gaps.
Here is our finished application of the paste laminate. We
are now ready for our final three layers of fiberglass
cloth, beginning with our laminating resin. You do not have
to wait until the paste laminate hardens before applying
the final layers of fiberglass cloth.
Notice how we are starting at one end of the part and
working our way to the other end. This not only allows us
to keep track of where we’ve applied our material, but it
also helps us recognize which side should reach the almost
tack-free state first.
Our first part is now complete and ready to cure overnight.
If we had been following the epoxy laminating system, we
would still be laying up our maximum of 12 layers of
fiberglass cloth per day and then have to finish up the
part tomorrow to add the additional layers required to
build a strong tool.
Day Two:
After 16 to 18 hours, we are ready to create the second
part of our mold.
We begin by removing the sheet wax that formed our parting
line. Then, using a razor knife, we clean up the edges of
our fiberglass layup.
To clean up the clay that was used to attach the sheet wax,
we use a fillet shaper tool to scrape the clay and a rag
wipe off the remainder.
Next, we attach new pieces of sheet wax to complete the
second parting line. Again, we’re using Plast-Econ modeling
clay to adhere the wax and our fillet shaper tool to clean
off the excess.
After applying the Wood and Plaster Sealer to the sheet
wax, we cover the ends of the first part of our mold with
masking tape. This is done to prevent the any of the new
material from accidentally seeping into the edges of the
first part and therefore locking the two parts together.
Finally, we apply our two coats of Wax Release, two coats
of PVA and our last layer of wax release. Our wax release
will also dissolve some of the excess clay that we hadn’t
removed earlier.
The remainder of our paste laminating is exactly as we did
the day before, applying two layers of surface coat, three
layers of
Fiberglass cloth, our 1/2” thick layer of paste laminate,
and finally our last three layers of fiberglass cloth.
On the third day, we created our third part just as we did
parts one and two and here on the fourth day, our tool is
complete and we’re ready to demold. Notice the makeshift
stands that we’ve attached to the outside using our
Tuf-Fil. This is so we can later turn the tool upside down.
Before we demold, we are drilling holes through the lips of
our mold to ensure perfect alignment of our three parts
later. We are inserting brass dowels into the holes.
Here we are placing wedges at the parting lines and tapping
them with a hammer. Because we followed the proper sealing
and releasing procedures, we are able to demold each part
cleanly.
Notice the green PVA mold release on our tool, which can be
easily peeled off and washed off with a damp rag.
Since we drilled the alignment pins before demolding, we
are ensured perfect alighment when reassembling our tool.
Here you see a sideview of the paste laminate. Again, had
we created this tool using the epoxy laminating system, it
would have taken many more hours, plus an extra three days
to create a mold this rigid and strong.
For even less working time, you may forgo the fiberglass
layup steps, especially for smaller or less demanding
projects. Freeman also offers Freeman 1030, a new
lightweight urethane paste material that can be applied
with a paddle rather than being rolled out.