shaped your nose and/or scuttle to fit your chassis and powerplant,
and now it's time to mount the flanges. If you've never worked
with fiberglass reinforced plastic (FRP, commonly known as "fiberglass"
to the laiety) before, this is a great first FRP project because
it's pretty near impossible to screw this one up. Here's a quick
and easy way to do the job.
—an ounce of
polyester (or epoxy or vinylester) resin. It will probably come
(methyl ethyl ketone peroxide) catalyst for the above (see specific
instructions for the epoxy you're using, if you're using epoxy
—a pair of
latex gloves (available in boxes of 100 from pro paint suppliers,
Harbor Freight etc, or mooch a couple from a beauty salon)
preferably safety goggles or a face sheild but safety glasses
at the minimum. You really don't want to get this stuff in your
—a couple small
—a couple small
wide masking tape
—a well ventilated
workspace, with a couple/few layers of newspaper over anything
you want to stay nice
We'll use a nose
(which we'll call the "part") as our example; the scuttle
works the same way. We'll do the left flange here; the right isn't
Step 1: Mask the
outside of the part to 2" from the edge, so if you dribble
you won't be scraping hardened resins off the pretty side of the
part. The flange is the long L-shaped (in cross section) object
at the bottom of the photo.
Step 3: Put one of
the fiberglass mat strips (not listed in the "You'll need"
part of these instructions because Kinetic supplied them; they're
in the bag with the flanges) where the flange will mount…
Aha! You're wondering
what happened to Step 2. Step 2 is where you sand the gloss off
where the mat is laid, both on the part and on the side of the
flange. 80 grit sandpaper works fine; you want to get some "tooth"
for the resin to adhere to, plus sanding will remove any slight
surface impurities that might hamper a good bond. In the photo
above, you can see that the mat is on a spot that looks frosty
rather than shiny; that's because I already did Step 2.
Step 4: Put the
flange on top of the mat. You can see on this example there's
a red felt penned "L" on the bottom of the flange, about
mid-flange, and a red arrow forward of the L. You can also see
how sanding the side of the flange has made it a frosty opaque
instead of a glossy clear. Also note the flange is placed forward
of the recess for the hood (hey, we're in America), as needed
to make it fit flush against the side of the nose.
Step 5a: Tape the
bottom of the flange to the edge of the part, leaving half the
Step 5b: …then
tape the overhanging tape to the outside of the part. This positions
the flange precisely, with the proper spacing for the mat between
the flange and the part, and the tape makes a handy hinge for
the next step.
Step 6: Flop the
flange over so the mat is exposed. Temporarily remove the mat.
Note that against the blue background of the tape, it is easy
to see the felt pen markings on the flange.
Step 7: Put on your
gloves and goggles. Put half an ounce of resin in one of the paper
cups. Bathroom-size Dixie cups work well for this, You don't actually
need half an ounce, but it's hard to measure much less than that.
Add 10 drops of catalyst (8 drops if it's a hot day) and stir
it well with a popicle stick or whatever. Wet both the part and
the bonding surface of the flange, you'll know you didn't miss
a spot because wetting the surfaces makes them clear and glossy
Step 8: Lay the mat
in place and wet it out with the resin. It too will become clear.
If there are bubbles under the mat, poke them out with the tip
of the brush; jab the bubbles toward the edge of the mat. You
don't have to rush through this part of the job, you have about
15 minutes before the resin starts to gel.
Step 9: The reverse
of Step 6; flop the flange back on top of the mat. You can see
if there are any bubbles between the mat and the flange, and if
so, deal with them by tilting the flange back and fluffing up
the mat in the low spots (you can use the brush to move the fibers
of the mat around; after a couple of minutes the binder that holds
the dry mat together will dissolve in the resin and the mat will
become a bunch of fibers flying in loose formation rather than
an object in its own right.
If you've done a
neat job so far, you can tape the flange down firmly—not
surprisingly, masking tape won't stick to wet resin—or put
some weights on it (pocket change is good). Let the part rest
somewhere warm for an hour (70 degrees f. or so) or until the
resin isn't sticky any more, and then pull off the masking tape;
the resin will be firm but not yet hard and drips (if any) will
be easy to remove with a razor blade. Then flip the part over
and do the other flange on the other side (use a new brush and
cup). In a day, the part will be cured and ready to install on
FEW NOTES ON THE FIBERGLASSING PROCESS
Anything you touch with catalised resin will be permanently hard
tomorrow. This includes your clothes, your tools, the walls, the
floor…but it's not hard to be neat on a small job like this.
I did this flange with a camera in my left hand (see photos above)
and didn't get any on the camera. However, accidents happen, and
if you're going to do lots of fiberglassing in your career you'll
want to sacrifice a set of old clothes to the resin gods.
resin is available in small quantities at most big box hardware
stores (e.g. Lowe's, Home Depot) for about $10 a pint or $15 a
quart, including catalyst. Keep the can sealed after you're done
with the flanges and it will last for years. If you're buying
all your fiberglass parts from ouside vendors (me me pick me!)
that resin will be all you'll need for the whole car. If you're
designing and fabricating your own parts (which is fun but time
consuming, and if you're only building one car it'll be more expensive
than buying the parts outright) you'll need lots of resin and
lots of other stuff but that's another story (if there's interest
I'll do another how-to on creating your own parts). We don't include
resin or catalyst with our parts because the hazmat shipping surcharge
on an ounce (the resin is flammable and the catalyst will oxidise
dang near anything) is more than the purchase price of a quart.
•You can clean
your resin tools with acetone, but on a job like this I don't
bother. Your tools in this case are two brushes and a popsicle
stick (or other sacrificial stirring device) and it's easier—and
probably cheaper, and probably better for the planet—to
toss them than to clean them. Once the resin has cured, it's a
solid plastic and pretty benign, but as long as it's liquid (which
includes being liquid dissolved in acetone) it's a hazardous waste.
do fiberglass fabrication without eye protection any more than
I'd grind metal without eye protection. I used to when I was young,
and I didn't wear gloves either, but the list of dumb things I
used to do is long and distinguished and I know better now…and
now, so do you.
IMPORTANT NOTE: Do
<not> use the flanges as attachment points. The flanges
that fit against the frame rails are there to eliminate edge gaps
and give the part something to sit on while it's being attached.
Attach the part to the chassis with fasteners that penetrate the
part itself, fasteners such as bolts or Dzus fasteners. We are
making new molds that will produce much narrower flanges, which
should eliminate that temptation. Weight is the enemy of these
cars, and to make flanges robust enough to serve as "hidden
mounts" they would have to be made heavier and would need
a greater bonding surface.