Overview

Dear Modeler,

Your fuselage consists of 3 layers of 6 ounce cloth on the forward half of fuselage and 2 layers of 6 ounce cloth on the rear half. We use the West epoxy system. (Resin)

No bulkheads are necessary for fuselage strength. The plans show several for those that are more comfortable using them or need them for push rod supports. We recommend a firewall "sandwich" of two 1/4" plywood pieces; one inside and one outside of the fuselage (inside only is okay). A tail wheel bulkhead only to hold tail wheel assembly...keep it light, 1/8" aircraft plywood for example, and drill lightening holes where able. Add forward and aft wing hold down plates and that's all the structural plywood that you need. Keep it light!

If you desire other bulkheads we recommend you consider light plywood or blue foam. Servo trays should be aircraft plywood - not light ply.

We use the West epoxy system or Hobbypoxy Two to attach wood to fiberglass. Do not use polyester products. You may use other epoxy glues to attach your parts, but 20 minutes or longer set up times are desirable for stronger bonding.

Remember epoxy resin or epoxy glue only.

Please read through entire instructions and compare to plans.

General Instructions

Wash all epoxy parts thoroughly, inside and out, with cold water. A garden hose set to maximum volume is excellent. This removes mold release chemicals.

Water sand away all ridges and sharp edges with 320 grit sandpaper, and then with 400 grit.

I put a light coat of grey primer on epoxy parts and apply PPG Spot Putty, "REDCAP", to all pin holes and wet sand with 320 - 400 grit sand paper. Repeat as needed. (When you re-prime you may find more pin holes.)

If there are any cut outs shown on plans or fuselage, do them now. I use either a Dremel Cut Off Wheel (Fiber) or a small Exacto saw.

I now cut out all templates from plans and make any wooden parts. As a general rule, I epoxy all my fuselage parts in place at this time, except for the horizontal stab dihedral braces. Use only epoxy products, not polyester.

Hobbypoxy Two is excellent for attaching wooden parts to fiberglass. I come back 24 hours later with Hobbypoxy Three and make fillets around my firewall, wing hold downs, bulkheads, tailwheel brackets, etc. Use your finger to form smooth fillets...use surgical gloves if you feel the need. Wet your finger with plain rubbing alcohol when smoothing and blending in Hobbypoxy Three.

Notes: If you find a hole or slot too big, or wooden parts too small, fill with Hobbypoxy Three.

I attach my engine directly through the firewall with bolts and aircraft nuts/blind nuts.

Fit canopy....Trial and error is the only method I know. Make small corrections until it fits. Later I’ll install it with PolyZAP, then Hobbypoxy Three used as a fillet on the bottom outside edge of the canopy will hide any imperfections and lock canopy solidly onto fuselage. I install the canopy after the internal bracing and rails are painted and before painting fuselage. I also rough up the canopy edges and fuselage slightly so the glue will hold better.

Wing and Tail Feathers

1.) There are 2 basic methods of preparing foam surfaces.

A.) Sheet all foam pieces, top and bottom, then cut out all control surfaces; elevators, rudder, ailerons, etc. (I use hacksaw blade or a small fine bladed keyhole saw.)

OR B.) Cut out all foam parts, then sheet.

I recommend "A" . I find parts stay straighter with "A" method

Note: I like to use 3/8" to ½" balsa on both sides where control surfaces will be hinged; so you must cutoff additional foam areas to accommodate balsa thickness. Use Hobbypoxy Two or similar glue to attach balsa to foam. Pica white glue is another excellent product for this job.

2.) Since I glass all my balsa-foam composite parts, I sand all my trailing edges just enough to fair with fixed surfaces and they have a round radius edge of approximately 3/32"; not a critical measurement. Sheeting is generally 3/32" balsa or 1/64" plywood; 1/16" balsa is good on tail surfaces for lightness of construction.

3.) I cap exposed edges of foam surfaces, like ends of ailerons, elevator and bottom of rudder with ¼" balsa and on fixed ends of stabilizer. This adds a little strength and allows easier fitting of moveable surfaces; by giving you a sandable surface without fear of getting into the foam.

4.) Install wing, stabilizer, rudder and leading/trailing edges on all surfaces as appropriate.

5.) Fit, slot and hinge all surfaces TEMPORARILY; do not glue yet. Fair moving control surfaces into the tips and adjoining areas.

6.) Horizontal stabilizer and wing - I like to join my foam wing sections together with Pica white glue. From the bottom side, cut out balsa and foam to the length and width of respective dihedral braces. Try not to cut through the top side of the balsa, but it is no problem if you do. Use at least the front and middle dihedral braces. These braces can be used later to carry the landing gear loads

A word about dihedral angle. You may take a little out if you want a faster rolling ac. I wouldn’t add more dihedral. As you determine the amount of dihedral you want, sand the abutting wing ends (Root ends). If reducing dihedral, I let middle of dihedral brace hang below wing and sand even with wing bottom. Use Hobbypoxy Two to secure in place. Apply Pica or Hobbypoxy Two at the butt joint and dihedral brace area. I like to add some cotton flocking, cab’o’sil or micro balloons to thicken Hobbypoxy Two.

Notes: With a foam wing that is sheeted and glassed the dihedral brace adds some strength, but its main purpose is to spread the landing gear load throughout the wing. Wing strength is derived mainly from the sheeting, balsa or plywood, and the application of fiberglass cloth to make a composite unit. Therefore I usually use 4 ounce cloth from the wing root to just beyond the landing gear area on the top and bottom of the wing. I then cover the entire area with Dan Parson's light fiberglass cloth. I put the finish layer of glass on while the 4 ounce structural glass is still wet. This technique results in excellent bonding of the materials. The West epoxy resin is used for the wing and tail finishing process.

Sheeting - Wing, Tail, Rudder

Normally you will find that 3/32" or 1/16" balsa is widely used; 1/64" plywood sheeting is also being used. I like to use the balsa as it allows me to rough fit parts and sand them to fit. With the plywood, you need to be very accurate from the start.

Attaching sheeting to form

The foam cradles that the parts come in should be used when attaching sheeting. This will help insure that parts will be a true match and built-in wing washout (2°-3°) will be maintained in finished part (wing). If using balsa sheeting butt glue enough pieces so that you overlap all four sides of the parts to be covered. This can be attached with Hobbypoxy Two, sorgum, corebond or contact glue. I keep parts in their cradles and attach top surfaces first. If dihedral braces, wire tunnels, servo boxes, etc., need to be cut out, I do this now. Then I attach bottom surfaces. Don’t forget to mark bottom sheeting before gluing as to slot, box, etc., locations.

Notes: 1) Consider putting a piece of wax paper in cradle to keep from sticking to cradle if glue seeps out.

2) Weight part down in cradle if not using contact cement; as you want cradle to maintain parts shape.

3) Insure that you have cradles on level building board, door, etc.

4) This same technique is used on the tail surfaces.

5) Next attach leading/trailing edges, tips and end caps.

Wing Dihedral Braces

When installing, make braces a tight fit to insure good bond on foam and to lessen areas for epoxy to pool up, generate heat and melt some of the foam. Always install from bottom. My preference is to install after sheeting, but before is okay too. We use dihedral wing braces of 1/8" aircraft plywood and tail braces from 1/16" or 3/32"aircraft plywood. Hobbypoxy Two or Pica white glue is my choice. However, other epoxy glues are acceptable, but try to use those with 20 minutes of curing times or greater. This results in a stronger bond and prevents foam melt down.

Fuselage

I build the fuselage up first since this is the part with fixed areas that give incidences, offsets, etc. The wing, tail, rudder, etc., are foam and balsa and can be modified or adjusted easily to make final fits to glass fuselage. Fiberglass parts are from 3 to 2 layers of 6 ounce Glass. As a "general" rule the front half of the fuselages, engine nacelles and cowls have more layers then aft areas.

Notes

1. Do everything you can to keep the area aft of the C.G. line as light weight as possible. Light weight balsa, light ply, lightning holes, etc. all help. However, don’t go overboard in reducing dihedral bracing weight!
1. Don’t allow any epoxy resin or glues to "pool up" in a foam area as the heat generated during the curing process can melt your foam.
1. When applying multiple layers of glass cloth, I like to use a "wet lay up" technique. Use a slow setting resin 30-40 minutes or more. Put down and smooth out first layer of glass cloth and immediately come right back over first layer of cloth with 2nd or 3rd layer while epoxy resin is still wet. I use a roller and work cloth into resin with it. Just roll it down. Use enough pressure to allow first layer of resin to wick through to 2nd or 3rd layer. Only add more resin if dry spots appear in cloth. This will bond layers together to produce the strongest and lightest lay up. The roller is a four inch one with throw away roller jackets. Cloth gives strength. Resin is the bonding agent and provides no strength; only extra weight if put on heavy.
2. The procedure is to lay the cloth down, cut slightly oversized, on a dry surface. Next, pour some resin in the middle of your cloth area and roll out slowly in all directions. You can use the end of your roller jacket to pull and work out wrinkles. If another layer is desired, lay the cloth on top of wet area and roll into initial cloth with some pressure to bond two layers together. Repeat as desired.
1.  

A. Wings: 4 ounce cloth used to just outboard of main gear or outboard engine nacelles and then "Dan Parson’s" 0.6 ounce cloth used to cover this area plus rest of wing. Do this to both sides.

Rudder/Stabilizers/Elevators: I cover with two layers of Dan Parson’s 0.6 ounce cloth. 2nd layer is laid 90° to first layer. Three layers is even better.

B. After this cures, 24-48 hours, I sand in all rough areas and repeat to other side of wing, tail, etc. After curing, I then final sand both sides to finish quality and then apply a coat of resin to entire part, one side at a time, to fill in the glass weave and sanded edges. Keep this coat as light as possible. I usually mix up my resin and then cut it with alcohol to about 25 to 50% alcohol to resin. Experiment to find the right mix for your epoxy product. After this application dries, I like to wait 72 hours, sand to finish surface and prime. I use "PPG" red cap automotive putty to finish any rough areas.

5. Horizontal Stabilizers - My stabilizers are designed on most, but not all my ac, to butt up to the sides of the fuselage and NOT pass through it. We use dihedral braces to pass through small slots in each side of the fuselage that you cut out to match the size of these braces. I find this technique allows easier alignment of the stab and a lighter set-up. If you desire a continuous stab, simply glue some foam in between the two stab halves, sand and sheet.

Engine Set-up

Single Eng. aircraft 2° right thrust Multi Eng. fighters 0° thrust

2° down thrust and bombers

C.G. Set Up

See plans

* If and when making changes to thrust vectors or C.G. set up - do them in small increments.

Glue Use

To attach: Wood to fiberglass - epoxy glue or resin

Wood to foam - epoxy glue or Pica white glue on both sides

Foam to foam - Pica white glue or epoxy glue on both sides.

Balsa or plywood sheeting to foam - Sig core bond, Dave Brown sorgum, Hobbypoxy Two or contact cement. (some of later attack foam) Same for plywood sheeting.