WEEK 12 | Composites
Hydrostone & Rag
The ratio was 32 parts water for 100 parts plaster by weight. We decided to use a brush to spread the plaster. We realised that we should have poured more plaster in the mixture. We had to take out some liquid in order to stick the rag to the mold otherwise it wasn't a big issue.
Sugar & paper
I wanted to test sugar as a matrix. It was my first caramel and I discovered that sugar becomes hard very fast! Indeed I made a mess and the result isn't very pretty but I had a lot of fun.
For next time:
- Don't burn the caramel (because it smells bad),
- Maybe use a smaller mold,
- Use a material smoother than paper.
Rice paper, jute & hot water
Week Assignment
Rough cut drill bit: 1/8"
Finishing cut drill bit:1/32"
I left the composite is the vacuum bag only few hours. But the paper rice took two days to cure so the details at the end of the rosace were not what I expected.
Test 2: Rice paper, chiffon & hot water
I chose chiffon instead of linen because it's thiner and I was hopping to see more details. I left the composite to cure totally in the vacuum bag. With these two modifications from Test 1, I had a much better result with the details. But a few days later I realised that the composite started to bend and loose its curvy shape.
Finally, I decided to make a test with the resin.
The composite is more reliable with resin (even if its much more fun to play with rice paper). The result is smooth and it doesn't bend. Otherwise the precision of the details is similar to the second rice paper test.
Second rice paper test and resin test results.
CarboGlass visit
Fab Lab Wgtn and Massey University 3D Workshop organised the visit of a composite factory. It was very useful, we had a better idea of what a composite is and what we could do with it. These pictures show one of the two techniques we've seen.
1. Spray some glue onto the bottom of the mold,
2. Place the carbon sheet on it, be careful with the angles,
3. Spray "vacuum Infusion Enabler" (this glue is pigmented so he didn't use it on the bottom layer),
4. Repeat 2 & 3 few times,
5. Spray some pigmented glue and add a layer of cloth,
6. Place the green mesh: it'll help the resin to spread up faster,
7. Close the vacuum bag and start the extraction
8. Wait at least 10 minutes
9. With the second tube, put the resin into the bag. It'll spread uniformly over the top of the composite.