To continue in the custom
make door panels process you should now have fully prepped
your custom door panels using the previous steps in this how to custom
make door panels article, you are ready to do some work with
fiberglass resin. This is the section that requires the most
patience, So, think about what you are doing and try to be safe.
next steps in customizing your door panels involve using your polyester
blend t-shirts, staple gun and spray adhesive.
Remember: Always wear protective gloves, safety goggles, and a
dust mask when working with any kind of fiberglass or resin
If using t-shirts, make sure they are polyester blend. This
is recommended because the fiberglass resin will actually bond with the
polyester fibers in the shirt for extra strength. The number
of shirts you need will depend on how large of an area your are
covering in resin. I used 1 shirt ( front and back) to custom
make door panels for the front of my custom Impala SS
- You will need to cut the sleeves off of the shirt and also
the collar portion. Now make a cut all the way up the side of
the shirt so It can be opened up fully. Also stretch the
shirts out very well to help loosen the fibers up.
Now apply spray adhesive all over the front side of your door panels.
Also apply the spray adhesive on the inner edge of the panel.
and place the t-shirts onto the panel.
- Try to keep the shirt from wrinkling up and stretch it
tight over any mounts or pods that you have created out of
wood. The tighter, the better!
Use your staple gun to help hold the material in place, especially in
areas where the shirt is stretched tightly. Just remember to
try and make the t-shirt material as "flowing as possible with nice
curves and no wrinkles.
If there are any holes on the edges of your door panel that are used to
mount pieces to, like the top edge of mine where the upholstered panel
goes, use a Sharpie marker to mark the holes at this time in order to
properly custom make door panels. This should include any
section that screws go through to mount the panel back onto the door
itself. Use a bright colored marker (blue, red, green) to
mark these holes on the t-shirt.
If you haven't already done
so, lay down some plastic drop cloth on your work bench to keep it
protected during the next few steps.
Apply your first coat of resin, after mixing it up. Apply it
with a short hair, inexpensive paint brush. Two inch wide
brushes are perfect to custom make door panels for your ride!
- This is done by first mixing the resin with its
activator/hardener per the instructions on the label of the resin
container. With the resin, you will be given a small tube of
liquid hardener. The hardener tends to be used up rather
quickly, so try to have some extra tubes of hardener on hand.
- Do not try to
add more hardener to get the resin to dry more quickly!
Follow the instructions exactly as they are stated on the
resin container. Adding too much hardener will allow the
resin to harden too quickly and won't give you enough time to apply it
to your work piece! Too little hardener will not allow the
resin to fully cure, or dry.
- Don't mix all
of the resin at one time! Only small amounts are
necessary at a time. You can always mix more up.
- When applying the first coat of resin, don't simply paint
the surface of the panel with the resin. You actually kind of
have to stab the resin into the shirt with your brush. Doing
this will allow you to fully penetrate the the threads of the material
which will add to its strength. Be sure to work out any air
bubbles that appear with your stabbing motion.
- Also apply the resin around the edges to the backside of
the panel. You don't need to coat the entire backside, but do
apply at least two coats of resin over the edges of the panel
- Completely saturate the entire surface to custom make door
time that you custom make door panels with fiberglass resin that the
drying of the resin tends to shrink and this can cause your
door panels to warp if certain precautions are not taken.
- To prevent the door panel from warping, you can do two
- Screw the door panel down onto your work bench in as
many places as possible. After your first coat of resin, it
will be necessary to drill holes through the resin you just applied to
allow the screws to go through the panel. Try to utilize the
door panel's original screw hole locations.
- Mount the door panel back onto the vehicle it came from
and apply the res of the fiberglass resin while it is still on the car.
That just sounds
scary to me though. I did the complete process
with my door panels screwed to my workbench. They did warp
ever-so-slightly, but they straightened back out when I mounted them to
my car doors at the end of the project
Allow your first coat of
resin to dry for at least two hours and apply the second coat of resin
while the first coat is still tacky, or sticky, but not wet.
- If there are any areas that need some extra strength you
should cut up a sheet of mat and apply them with resin in your second
coat. Wear gloves and a
dust mask when handling the fiberglass mat!
To custom make door panels that are strong enough for everyday
use, and or abuse, use fiberglass mat to reinforce the high stress
areas (like the door pull or armrest for instance)
- cut the fiberglass mat into several small pieces and
overlap them when applying to the door panel surface for added
strength. First apply a little resin where the mat will be
placed, put the mat in position, then cover the mat in more
resin. Again, work out any air bubbles that form with a
After the second coat dries
for at least 4 hours, sand down any high spots in the resin with 60
grit sand paper and apply your third and final coat of resin.
Try to get this coat as smooth as possible. Let the
final coat of resin dry for at least 24 hours.
After the final coat of resin is completely dried, unscrew your door
panels from the work bench and trim off any excess resin from around
the edges, by either sanding or sawing it off.
The next step is to sand the entire panel down with 150 grit sand paper
to completely level the surface.
- You will have some high spots and low spots. The
high spots are the biggest concern because the low spots will be filled
up with body filler in the next section.The idea here is to get the
panel as smooth as possible without going through the resin that you
have previously applied.
- Use a sanding block/pad, the longer it is, the better
results you will have on the big flat areas. Use your
hand/fingers on the curved areas and try to get them as "flowing" as
- If you happen to go through the resin in any area, reapply
resin to these areas and re-sand after it dries.
- After you feel the panel with your hand and think that it
is as smooth as you can get it, thoroughly clean the panel to get rid
of any dust residue.
Trim off any excess
resin, or material on the back of the panel that will prevent your
custom door panel from mounting flat against your door.
Trim out the opening of where your speakers, or any other add-ons, will
mount when you custom make door panels. I did my trimmings
with a dremel tool and a cut-off wheel attachment.
Check to make sure your door panels will still fit on your car or truck
before continuing! This
step is very important!
You need to be able to
fully install them before continuing to the next step.If you feel like
you need to go back and trim more resin off, or add more in some areas
to assure that your custom door panel fits the way you want it to, now is the time to do it!
(I marked the areas on my panel that were a little thick and prevented
the panel from sitting flat on the door while I held it in place.
I sanded the area(s) down until it fit perfectly)