AA-22901-DOC001

VT HOKIESAT SIDE PANEL ASSEMBLY PROCEDUREDATE______

side panel # ______

Note: To ensure part cleanliness and reduce the risk of contamination, rubber gloves should be worn at all times when working with the flight hardware. Glasses are recommended when using MEK to eliminate splash hazard. Entire procedure including surface prep and epoxy process should be done under a fume hood.

Step-by-Step Bonding Procedure; 25 steps, 2 pages

  1. Turn oven on to preset temperature (80 ± 10 degrees Celsius) to allow it to reach steady-state.
  2. Ensure clean workspace.
  3. Cover side panel surfaces not to be bonded with masking tape, particularly along outside edges.
  4. Solvent wipe copper wire, small spatulas, and thin aluminum square with MEK.
  5. Solvent wipe both surfaces to be bonded as well as spare aluminum pieces with MEK until cloth shows no more color.
  6. Clean both surfaces to be bonded and spare aluminum pieces with isopropyl alcohol (use separate cloth for alcohol applications).
  7. Following the steps below, mix 3M Scotch-Weld 2216 B/A epoxy part B (base) with part A (accelerator) by weight, using the calibrated scale located in the MSE lab (Hancock 108), according to the technical data sheet. Use small plastic cups for mixture and save plastic cup.

(a)Mark plastic cup with side panel number.

(b)Place cup on scale.

(c)Measure and record weight of cup: ______g.

(d)Tare the scale and cup.

(e)Add epoxy part B to cup on the scale.

(f)Measure and record weight of Epoxy Part B : ______g.

(g)Desired weight of Epoxy Part A = [ ______- ______] x 7/5 = ______g.

(h)10 % tolerance on Epoxy Part A = (c) x 0.10 = ______

(i)Required weight of Epoxy Part B plus Epoxy Part A between ______g. and ______g.

(c) + (f) (c) + (f) + (g)

(j)Actual weight of Epoxy Part B plus Epoxy Part A = ______g.

  1. Mix to a uniform color using the small spatula. Once uniform color is reached, mix for an additional 15 seconds.

Start working time: Tstart = ______a.m / p.m

Stop working time: Tstop = Tstart + 90 min. = ______a.m. / p.m.

  1. Mark a spare piece of aluminum with side panel number and place a small amount of excess epoxy on it. Cure this sample in the oven with the side panel under identical conditions.
  2. Cut 0.005” copper wire into four long pieces and spread them across the width of the isogrid panel trying to avoid the isogrid gaps.
  3. Spread epoxy on side panel surface to be bonded.
  4. Drag aluminum bar across side panel until epoxy is of uniform thickness. Drag in one direction only and along copper wire.
  5. Remove copper wire and touch up gaps with small spatula.
  6. Apply epoxy to side panel skin using thin aluminum square. This layer is very thin.
  7. Mate the two parts ensuring proper alignment and sufficient contact pressure for maximum bond area, as the panel may not be exactly flat.
  8. Move two parts around to ensure that the epoxy covers all surface area.
  9. Add a small amount of epoxy with spatula to outside edges of part to ensure adequate coverage.
  10. Place in oven with side panel down and skin facing upwards.
  11. Place weights evenly across the entire panel surface to make contact pressure.
  12. Bake for 120 minutes at 80 ± 10 C. Be sure to include marked epoxy sample.

Start bake time: ______a.m ./ p.m.

Remove fasteners: ______a.m. / p.m. (approximately 20-25 min. into bake)

End bake time: ______a.m ./ p.m.

  1. Remove from oven.
  2. Inspect all visible bond lines for gaps in epoxy. Large gaps may require re-application of epoxy and subsequent bake and cure process.
  3. Let cure at room temperature for additional 2-5 days.
  4. Complete assembly verification signature block below.
  5. Record new part number in tracking log, complete configuration log, and complete assembly log.

page 1 of 2

1

Assembly Verification Record

1

Assembled by: ______Signature: ______Date: ______

Witnessed by: ______Signature: ______Date: ______

AFRL Witness: ______Signature: ______Date: ______

Required Tools:

Calculator

Plastic Cups

Small spatula

Thin aluminum square

Masking tape

Wire cutters

Oven

2 Cloth rags for wiping

Rubber gloves

Protective glasses

Timer

Mass balance (NIST certified/calibrated)

3M Technical Data Sheet (for reference)

Required Materials:

MEK (Methyl Ethyl Ketone)

Isopropyl Alcohol

0.005” copper wire

3M Scotch-Weld 2216 B/A Gray epoxy

page 1 of 2