It's been a while since I've worked on Q7. Today, we applied the second layer of 6 oz. fiberglass cloth to the Q7 booster tube. While the first layer was successful, we were able to make some adjustments for the second layer and it came out nicer. Most notably, there are no ripples, wrinkles, or lifted spots.
Differences from the First Layer:
- More resin-rich cloth.
- This actually caused some difficulty initially. The cloth started sliding around the tube and getting misaligned. This was countered by changing the "burnishing" technique from diagonally and down, to straight out (along the tube). This prevented the cloth from sliding along circumferential direction as it was tightened.
- No Mylar layer was added once the cloth was installed
- Once the cloth was in place and the Mylar was removed, it was very easy to manipulate the cloth and smooth out any wrinkles.
- Relatively resin-rich areas were spread out with a brush
- More resin was brushed in at the end to any lighter areas to ensure adhesion
- The fiberglass overlap seam
- Some areas of the spiral (although there are light areas from the first layer that couldn't be filled)
- Mylar strips were wrapped around the two ends of the tube
- This forces the fiberglass down tight to the tube, so that it will be stronger once sanded flush.
Physical Results - TBD
It can be seen that the second layer of fiberglass increased the wall thickness by an average of 0.014", and added 303.5 grams to the tube. For a more useful weight figure, that's about 6.6 grams per inch of tube length. Compared to the first layer, the second layer was XX% heavier.
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| Finished 2nd Layer of Fiberglass |
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| Mylar Strip to Keep the End Clean |
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Mylar Strip on the Other End
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Surface Finish
Note the wetter areas that have been touched up. |
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Another View Showing the Varying Levels of Wetness
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