Please feel free to contribute your own tips - I'll post the best ones so everyone can see them.
you credit,of course!
Tip 1: Fiberglassing with epoxy
You will need: Epoxy laminating resin & hardner, mixing cups & stir sticks, acid brushes, plastic squeegees (1.5"x3"),
rubber gloves, acetone & disposable rags, fiberglass cloth (I use .56 to 1.5 for wings, .56 for empinnage, 2.0 for wood
fuselages), 100 grit garnet paper and 220 grit wet or dry sandpaper, a sanding block(Rubber), some clear plastic bags and
The secret to this tip is the polyester cloth. I get mine at the local fabric store. (Here in my
neck of the woods it's Jo-Ann Fabrics)
You want the finely weaved stuff, it looks like a silk scarf. I prefer white
but it really doesn't matter. You are gonna throw it away anyhow.
I use West Systems Epoxy for all my glassing. Any good laminating epoxy resin system will work, but West's works best for
With that said, on to the How to:
1.Get your structure built and sanded smooth.
Finish sanding with at least 220 grit wet or dry 3M paper. (On bare balsa use it dry.)
Fill all imperfections and
dings with a good spackling compound.
Resand and respackle as needed to get that perfect surface. Install and test
fit all hinging, but DO NOT GLUE THEM IN YET.
2.When satisfied with the surface finish, starting on the bottom
surface, cut your glass cloth so it will overhang the edges your wing about one inch all the way around.
enough pieces for both side of all the surfaces you are going to glass at once. One top and bottom for each part. Allow at
least one inch of overhang.
Cut enough pieces of the polyester cloth one to two inches bigger than the glass you just cut.
4. Mix enough laminating epoxy to cover the glass as per the directions of your epoxy system. On the average size wing, usually
about 1 oz.
5. Pour a bit of the epoxy in the center of the wing, squeegee the epoxy out to the edges. Adding epoxy
as needed with an acid brush. Make sure all cloth is down to the surface and with out wrinkles. You can remove excess epoxy
with the squeegee but Don't worry about having too much epoxy. (Within reason!) Just don't get too much on the edges, just
enough to let the glass hang down over the edge by its own weight.
6. Here is the trick part. Lay one of the pieces of polyester cloth directly over the wing (with Glass & wet epoxy already
Put on your rubber gloves and, with your fingers and the Squeegee, smooth the polyester to the surface
of the wing.
Be sure the polyester is overhanging the glass by about one inch or so. Allow to cure over night, 8
to 12 hours (at 70 degrees or more).
7. After the glue has cured, separate the polyester from the glass at one of the edges. Holding the glass down to the surface
of the wing, firmly pull the polyester back over the wing surface. Keep it as close to the wings surface as you can and peel
Work slow and Be careful, if you start to peel the glass cloth up with the polyester don't worry., I'll
tell you how to fix it. Just go to a different edge and start over, again being careful until you have peeled the polyester
completely from the surface of the wing.
Super hint # 1
If you started to peel a little of the glass from your wing, apply a few drops of CA to the area
and smooth the glass back down with a scrap piece of cellophane. I use those clear bags that parts come in. (It's called recycling)
Put your hand inside the bag and rub the glass back down. If the CA won't cure use a bit of "zip" kicker on the bag. Keep
rubbing 'til the CA has set up. Other wise you may glue the bag to your wing!
8. After you have peeled the polyester from your wing, use a sanding block with 80 or 100 grit paper and lightly sand the
edges of the wing until the excess glass and epoxy falls away. Remove any bumps or drops of epoxy from all edges.
the wing over and repeat the above steps on the other side.
(I do one side of all the flying surfaces at the same
Now you have all your surfaces glassed and the edges all cleaned up. It's time to do the finish work!
The polyester cloth you peeled away took off the excess epoxy resin and a shiny layer on the surface that is known as "Ammine
Bloom". It is this shiny layer that you have to remove in the old "Toidie Paper" method of fiber glassing.
Usually by sanding it away.
What you now have is a layer of a "Blue Million" tiny epoxy nails sticking
up from the surface.
9. Grab your trusty sanding block loaded with 220 grit wet or dry sandpaper, and lightly scuff
those nails down smooth.(It's a lot easier and faster to scuff them down, than it is to fill all the holes left by the "Toidie"
Dont sand through the cloth! If you do, use the CA method described above.
10. After sanding you
are ready to prime. (In just two days, I might add!) You can brush or spray the first coats of primer. I prefer to spray,
usually means less sanding. If there are a few holes in the surface after the primer is applied, add a little more with a
brush or using your finger rub the wet primer until they are filled.
11. Let dry as per the directions of your primer,
usually over night.
12. With the ol' block & 220 grit, wet sand the primer almost off. (Until you can see the
cloth starting to show.) You can add a few drops of dish washing soap to the sanding water, it helps keep the sandpaper from
clogging up. You should have a very smooth surface, with almost no imperfections. Fill any imperfections that are left with:
Super Hint # 2
Go to your friendly Auto Paint Store and purchase a product called EVERCOAT 400
POLYESTER GLASING PUTTY. This is a two part putty that is used by the auto body industry to "fill" small imperfections in
paint and primer before the final color coats are applied on your car.
13. Mix a small amount of this stuff to fill any imperfections that may remain. MIx it in small batches as it sets up in less
than 5 minites. When it is cured, it sands like butter!
Try it, you'll wonder how you ever got along with out it!
14. Mix a small batch of polyester glazing putty and fill any imperfections you may have left. Apply it with a small credit
card sized squeegee. Mix only what you can use in two or three minutes, as this stuff sets up fast! (Thats why you need to
use small batches!)
15. Sand the filled spots with 220 wet.
16. Spray the final coats of primer. I use
two, spray one with the length of the wing span and one with the width of the root. This insures complete and even coverage.
Allow to dry as before.
17. Block sand wet with 400 grit, until you can almost see through the primer. Primer is
HEAVY! You want just enough primer coverage so the paint will stick. Paint will not stick to fiberglass or epoxy.
NOW.... You are ready to apply that beautiful scheme you have been dreaming about!