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  2. Resin volume placed on foam

Re: Resin volume placed on foam

Rob de Bie
 

Eugen, I would be careful with vacuum bagging your parts. You're making quite a big change from the original building methods. The foam is not meant for full vacuum. And possibly it will absorb more resin due to the vacuum. I've done lots of vacuum injection, and the resin that goes into the foam cancels out all weight gains.

I fully understand your desire to build quality parts, but this might not work out so well. Maybe a light vacuum (if that exists :-) is a better way, say -0.1 or -0.2 bar.

Rob

On 23 Mar 2021 13:30, Eugen Pilarski wrote:
Dear Q-community,
the bulkheads of the Q1 are already cut and the worktable for vacuum-wrap is ready to go. After I study again the Quickie wokshop manual on page 3-11 in Step 7: Squeegeeing .......... If you’ve done an excellent job, the weight of resin will be about 2/3 of the weight of cloth used. ........
So we use glass with a weight of 296g/m2 and based on the number of Step 7 in Quickie built manual show up, that the requested resin will be 200g/m2 ( 2/3 of 300g/m is 200g). Is that correct?
But the laminate calculator of R&G get me out 243 g/m2 and is 20% more that Rutan numbers indicate, please find the link below: R&G laminate calculator <https://www.r-g.de/en/laminatecalculator.html>
Framework:
Fibre type: glass fibre - 2.6 g/cm3
Areal weight: 296g/m2
Fibre volume fraction: Hand-lay-up 35%
Number of layers: 1
Laminate thickness: 1mm
Width: 1000 mm
Lenkt: 1000 mm
Resin type: Epoxy Resin  - 1.15 g/cm3
print
Result:
Number of layers 1 Layers
Laminate thickness 0.33 mm
Fibre reinforcement surface area 1.00 m²
Fibre reinforcement gross weight 296 g
Resin quantity 243 g
Laminate weight 539 g
Fibre content (weight) 54.9 %
Fibre content (volume) 35.0 %
Did you guys fixed a resin volume per square meter during your building process as maximum or just the wet as should and dry as possible rule?
I ask to understood how may resin should be placed on the foam to reach the material strength and stay in low weight at all parts that need to produce. So sounds like the old story......
Best regards
Eugen
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