fiberglass parts can be easy or they can drive you crazy trying
to get the kind of finish that you want. I have been painting fiberglass
racers, cowls, and wheel pants for many years. I have done it the
hard way and now I do it the easy light way. I am going to share
this with you.
The most difficult thing to overcome with fiberglass parts is filling
the pinholes and not getting frustrated while you are doing it.
I have tried the many things, like brushing the first coat of primer
on the pieces then sanding and doing it again… It gets rid of
some but not all. I have tried to fill them with primer by spraying
on heavy coat of primer then using a brush to fill them in… Too
much work and it is heavy. The method that I am sharing with you
is a great system and is fast.
The first thing you should do is clean the parts with soap and water.
The mould release that most the manufactures is water-soluble. The
next step is to sand the entire piece to be painted. If there are
some large areas that need some filling, use some of the new poly
fillers, such as "Icing"… They are ready to shape in about 15
minutes and ready to feather out in about an hour. Do not forget
to do the shaping before the cure is completed. After the cure,
it is hard to sand. Do the shaping with 80 grit. The finer grits
will plug and not get the job done. After it cures, then feather
it out with finer paper.
If you have done the filling and sanding as above, you will have
opened even more pinholes than you had before. Now take your air
gun and blow the entire surface clean of all dust. Do it hard, so
that you will blow any sanding dust out of the existing pinholes.
Pinholes are not a problem at this step with this system. The next
step is a little messy on the fingers, but it will wash off with
soap and water. Use a filler like Model Magic, Dap, or just any
of the water based spackling compounds that you can find at your
local stores. First thin it out to the consistency of heavy mayonnaise.
Now dip your fingers in the filler and rub the entire piece down.
Don't try to fill any specific holes, just rub the entire piece
down with small circular motions. Pretend that there are pinholes
everywhere and you are pushing the Spackle in all of them. After
you have the entire piece done, set it aside and let it dry completely.
It can take a couple of hours. After it is dry, sand the entire
piece down with a 220 dry paper. Now you have to be careful. You
want to remove all the Spackle from the piece, but you do not want
to make any new pinholes by over sanding.
When the entire piece is sanded, you should have little or none
of the Spackle showing. You do not want any excess. Excess anything
in the painting process is excess weight on the finished product.
The next step is priming. Spray a coat of 2-part primer on the entire
piece. It should be a medium coat, not a heavy one. This coat of
primer blends with the spackle and will now make it water proof,
so that if you want, you can wet sand this coat. You want to sand
most of the excess primer off with this sanding. You only want a
thin coat of primer remaining. Try not to sand through the primer,
but if you do it is not a big deal. When you are finished sanding,
go back with primer and just cover the spots where you sanded through
with a light coat of primer. The goal here is to get the entire
piece smooth and one color for painting.
Like all painting projects, the work of doing the paint job is in
the preparation. The painting is easy. I spray on a tack coat. I
turn in the trigger restrictor so that I can control my first coat.
I just want an even mist over the entire area being painted. I let
this set for about10 minutes. I then open the trigger restrictor
to where I can get enough paint to cover and gloss. At this point
I am getting enough paint to get the full color of the paint I am
using. I look at it at this point, and if it is smooth and glossy,
I stop. If it is a little dry in spots, or trying to orange peel
a little, I put a flash coat on the top… Not much. The flash coat
is easy. I take the paint that is still in my gun and add some thinner
to it. I make it will be too thin to paint with, but that is not
the reason for the flash coat. It is to blend the topcoat with the
base and level it all out. Be careful not to put too much on at
this point. You can make a mess. It does not take much to make a
After you have them finished to this point, you can fix any blemishes
that you may have in your finish… That is a little dust, pollen,
or even bug feet… I paint outside.<G> You can sand any of
those kinds of things with 2000 grit and then either hand polish
or buff them to your liking.
There are many brands of paint that you can use. Automotive paint
seems to work the best of everything I have tried. There are one
step processes and two-step processes. See your local paint dealer
for his sales pitch and what he recommends. Tony Stillman has the
colors mixed to match most of the popular colors of covering film
in smaller amounts. You might consider using his painting system.
If you need some of the other products that go with it, you can
get them locally.
When I paint, I prefer to have a nice looking LIGHT paint job. I
have painted a complete Q40 racer and have only added an ounce and
one half to the weight of the airframe with a 4-color scheme and
clear coat. You can put lots of primer, lots of color, and lots
of clear and make anything look like a piece of china. It is better
to do it right and use less material to get the same results. If
you want the china finish, then color-sand your last coat of clear
and apply a second coat. With a light sanding and a power buff it
will look like it came out of a mould.
Painting our small parts is not difficult. Do not be afraid to try
it. You will be happy with the results.