Glassing and painting a wood fuselage

[Mike Hester]

Ok this has been a long time coming. I'm going to take it slow and be very thorough.

Why glassing and painting? Simple. It looks good and is very durable for the long run. You MUST glass the structure to stabilize the wood or else it will eventually crack, not to mention be much heavier. This is not hard and once you do it, you'll hate monokote for fuselages. it's a simple recipe that requires some special items and a lot of elbow grease.

I realize that this is a long list and it's not cheap. But it IS worth every penny.

Anyone can do this and be successful, but you MUST NOT DEVIATE from the instructions!!! The slightest change can cost you valuable ounces.

What you will need:

-.7 ounce glass cloth, 3 yards
-Superfil
-ultimate lightweight bondo
-glazing putty
-West system resin, 105/205 pint or quart kit
-acetone
-balsarite (film formula)
-PPG K-36 primer kit, 20 ounce kit (do NOT substitute!)
-Paint of choice, plus activators and reducers
-twice as much reducer as called for
-5 star cleaner/degreaser
-tack cloth
-sandpaper (220, 400, 1000 grits)
-foam sanding blocks
-foam rollers and frame
-unwaxed dixie cups
-1" disposable brushes
-paper towels
-Masking tape and masking paper
-3m fine line tape
-HVLP spray gun (mini size from Lowes works fine)
-Compressor capable of delivering 1.2 cfm constant with regulator
-inline filters
-gun side regulator (optional but NICE)
-fixture to hold parts (details later)
-PATIENCE!

[Mike Hester]

Begin by rough sanding the entire airframe with an 80 grit sanding block. All you want to do here is sand the plane to it's general shape. you'll be suprised at how close you get it with this step alone. be careful around the turtle deck area where it meets the fuse box; most of the sanding is to the fuse box part so it doesn't get into the 1/16" sheeting of the turtle decks.

Block sand the cowling area so the wood is flush with the fiberglass. It's normal to have a step or gap here. Take your time and don't remove too much material.

install the chin and canopy and sand the fuselage to match.

Now go over the entire airframe with 220 grit paper and a foam sanding block. You can get these at any auto body store.

The next step is filler.

First and foremost use Superfil, available from Aircraft spruce (pictured). This is a very lightweight 2 part epoxy based filler. The more of this you can use for filling, the lighter the plane will be in the end. Go over the entire plane blending the tail block area and the cowling attach area, and use it to fill imperfections, pinholes, etc. This stuff takes 24 hours to cure so use it liberally. It sands relatively easily. Just remember, balsa is lighter than any filler, so USE THE SANDPAPER to lighten the plane. if in doubt, sand some more. The more you leave in the floor, the lighter the plane and generally speaking, the better your plane will look. use the 80 grit block around the cowling to make sure you ONLY leave filler in the seam.

After getting the fuselage close with the superfil, leaving only very minor areas to work out, now switch to lightweight bondo. you have to work fast and do only a small area at a time. let this cure for a couple of hours, then sand with 220 grit paper to the desired shape. By this point you should be VERY close.

When you're almost home, use the glazing putty for the most minor of details. This stuff dries fairly fast and sand like butter, so be aware.

Once you have sanded and filled the plane to the desired stage, blow it off with compressed air and go over the entire airframe with 400 grit paper to make it smooth and ready for sealing.

[Mike Hester]

Make yourself some kind of a fixture to hold the fuse in the iar. it doesn't have to be anything fancy, but you should be able to rotate the fuselage and it be relatively stable.

Now once you have the plane mounted up, using a 1" brush paint down the entire plane in balsarite. Paint it on full strength. This seals the wood and stabilizes it for the base of glass. It doesn't take long to dry, only an hour or so, but the longer the better. paint ALL of the bare wood, but not the composites.

After this has dried, go over the plane and lightly sand down with 400 grit paper. it should be smooth, but don't sand it off!!!! As in, don't sand deeply. Just level it out.

[Mike Hester]

At this point, weigh the airplane. You need to know where you are so you can determine how much weight you're adding in the process. Write it down somewhere.

[glmiller3]

Mike,

I just checked the Aircraft Spruce website and they don't list "Superfill" It doesn't show up on their pages of adhesives or fillers either. When I google it, I don't get any hits for a filler material....any other sources that you know of?

George

[glmiller3]

OOPS, well, I went back to aircraft spruce and searched for "superfil" not "superfill" and found it...that extra "L" was killing me.