Strom, Rob, & Daniel

1. The step-by-step procedure.

  • Cover the table with a plastic sheet about 5 feet long.
  • Cut 4 strips of Bidirectional and 4 strips of unidirectional fiberglass.
  • Mix the resin and hardener together. One full pump of each.
  • Cover two sheets of either BID or Uni in resin on the table.
  • Squeeze out as much excess resin as possible.
  • Press the two strips together.
  • Repeat the previous 3 steps with whatever material you just used.
  • Spread resin on a sheet of foam and stick a stacked group on either side of the foam.
  • Squeeze out as much excess as possible.
  • Repeat the previous 6 steps with the Unidirectional or Bidirectional. (whichever one you didn't already use)
  • Clamp the pieces down on a table and label your sample clearly.

2. Safety Precautions.

When handling fiberglass and resin, you must at least use nitrile gloves and safety goggles. Long clothes are highly recommended and a mask is optional. (ALL 4 ARE VERY HIGHLY RECOMMENDED WHEN SANDING. Trust me.)

  • Use the specified amount of resin and hardener requested by your instructor.
  • Heat is produced from the chemical reaction between the resin and hardner, so the part may become hot.
  • Do not touch skin or eyes while wearing gloves.
  • When taking gloves off pull them off by turing them inside outa and discard them when finished with the activity.
  • Wash your hands with soap and water after activity.
  • The resin and hardener mix has a working time of approximently 30. If the resin begins to cure, it is no longer usable.

3. Identify the differences in wetting out uni- and BID fiberglass. Present a hypothesis as to why there differences exist.

When wetting out the bi you usual go from the center out horizontally and vertically to minimize the amount of resin in your sample. Though when you wet out your uni you can only go from the center out horizontally or your sample will fray and fall apart.

4. List the physical characteristics of your finished samples. Include:

  • size- length: uni-12.5in, BID-12.2in, uni sandwitch-12.3in, BID sandwitch-12in;

width: uni-2.2in, BID-2.1in, uni sandwitch-1.8in, BID sandwitch-1.9;
hight: uni sandwitch-0.5in, BID sandwitch-0.5in

  • wieght - Before: uni-37g, BID-35g, uni sandwitch-43g, BID sandwitch-35g

After: uni-35g, BID-32g, uni sandwitch-40g, BID sandwitch-35g

  • quality of consruction - There were small air bubbles on the edges of are samples.
  • any other physical characteristics of your sample-In our uni 4ply we had a glob af hardened resin caused by a hole in the board we used for pressure.

5. Judge your fabrication technique by including data on the weight differences of the samples. Provide suggestions for improvement of your technique.

Our fabrication technique was pretty good. Our samples did not have any major flaws and only a few minor flaws. We had samples that were lighter than most but were not the lightest of all. The only way to improve would be to use a stronger press to remove excess resin.

6. What impacts would using your original fabrication technique have on an actual airplane? What would a manufacturer do to mitigate these impacts?

Using our original fabrication technique a plane would have a horrible size to wieght ratio. A manufacturer would use powerful presses instead of hand turned clamps to minimize the amount of resin in the fiberglass.

7. Were your second day resluts better than the first day of construction? Why?

Yes, day 2 construction went much better than day 1. On day one we used too much resin on the samples, causing a excess amount of resin on the sample making it heavier. On day 2 we used a smaller amount of resin resulting in a lighter sample.

8. Propose a step-by-step procedure that eliminates (or tries to eliminate) the problems discussed above.

  • Cover the table with a plastic sheet about 5 feet long.
  • Cut 4 strips of Bidirectional and 4 strips of unidirectional fiberglass.
  • Mix the resin and hardener together. One half pump of each.
  • Pour a small amount of resin on either the BID or Uni in resin on the table.
  • Squeeze out as much excess resin as possible.
  • Press the two strips together.
  • Repeat the previous 3 steps with whatever material you just used.
  • Spread resin on a sheet of foam and stick a stacked group on either side of the foam.
  • Squeeze out as much excess as possible.
  • Repeat the previous 6 steps with the Unidirectional or Bidirectional. (whichever one you didn't already use)
  • Clamp the pieces down on a table and label your sample clearly.

9. Compare your samples to other group's samples.

Our samples were about the same as the others. We had less resin than most but not the least, and all the samples were about the same size.

10. Formulate a plan for using both uni- and BID fiberglass on an airplane. Give secific uses for both.

The BID would be used high stress joints and connections. For example where the wing connects to the body. While the uni would be used for the wing and parts of the fuselage.

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