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  • Discuss aerobody manufacturing process with Andy Philips of
  • Key considerations going forwards

Minutes

Item
WhoGoing with vacuum
Notes
Process
Vu Julian Hoa-Chau Huynh (Unlicensed), Andy

Vacuum infusion

The estimated
  • Estimate setup time
for a ca. 4m^2 area
  • of
mold is 8 hours to prepare with the layup and vacuum.  Additionally, vacuum checkup must be performed.The recommended weave for the fibreglass to be used is 2x2 twirl.  This allows
  • 8 hrs for first layup (everything prior to adding resin)
  • Vacuum check must be performed (to ensure vacuum can be held)
  • Recommended vacuum pressure should be 27 - 29 inches of mercury (near perfect vacuum).

  • Approx 45 min to 1 hr for epoxy to fully absorbe into fibreglass
  • For prototype mould, concerns about using envelope bag (if can't pull proper vacuum using reg. vacuum bag)
  • Envelope bag could crush and damage mould

Layup Materials

(Resin, Core, Fibreglass)

Fibreglass

  • Recommended weave for the fibreglass is 2x2 twill
  • Allows for complex curves and sharp ridges to be made from cut off strips from the roll
.  Additionally, cutting
  • Cutting the material at 45° will increase its flexibility by 25-30%
.
  • For the vacuum within the mold, the recommended pressure should be 27 - 29 inches of mercury.  To measure this, a vacuum gauge is to be used, which will cost ca. $25.
  • The estimated time for the epoxy and hardener mixture to fully be absorbed into the material will take from 45 minutes to 1 hour.
    • There should be 4 layers of fibreglass, however other numbers are possible dependent on the shape of the car

    Resin

    • The recommended available resin is MGS 135 resin, which can be mixed with a hardener to give it a longer pot life
    .
  • If the mold is not sealed properly, the envelope could crush and collapse onto the mold.
  • The spiral wrapping (is this what he meant?) to be used as the resin feed line is recommended, as it offers much greater versatility compared to other methods.
  • In order to ensure a good finish of the part i.e. a good paint job for the aerobody, an epoxy primer should be used in the mold instead of a gel coat.  This will reduce the weight exponentially and also allow for the painters to easily paint the car.
  • The core material to be used should be DIAB - Divinycell H60, however it needs to be cut to fit to size and

    Core

    • Foam "sandwich" core: DIAB - Divinycell H60
    • Flexible and can be cut to size
    • Core does not need to be everywhere in the
    mold.
  • There should be 4 layers of fibreglass, however other numbers are possible dependent on the shape of the car.
  • It is very feasible to include multiple complex components of the aerobody into one single mold.
  • To add lips and tongues for the trunks and the doors, dimensional wax can be used.  They come
    • mould (as curves, edges, etc will add stiffness too)

    Multiple Panels from Single Mould

    Dimensional Wax

    • Very feasible to make multiple panels using same mould (i.e outer skin of door + side panel)
    • Features such as insets and lips for overlapping panels can be added using dimensional wax 
    • Wax comes in sheets of 1-6mm thick, and can
     be molded
    • be machined and moulded using heat to fit the specifications

    Consumable and Equipment

    Resin Tubing

    • Spiral wrap tubing recommended to be used as the resin feed line
    • Offers much greater versatility compared to other methods

    Vacuum Gauge

    • Required to ensure pulling proper vacuum
    • Can be a cheap $25 gauge (vs. $300 gauge)
    Paint and Windshield

    Paint

    • Using a gel coat is not recommended for fibreglass
    • Instead using paint will reduce weight exponentially
    • An epoxy primer should be used inside the mould (similar to gelcoat application)
    • Will allow for good surface for automotive paint to adhere to


    Windshield

    • For the windshield
    , a company called can be contacted.VacuumingAndy, Former user (Deleted)Concerns about pulling a vacuum too hard onto the molds - too much pressure can crack the molds
    • , check out York Aircraft (make aircraft canopies)
    • Possibly consider using pre-made windshields for aircraft, boats, etc. and modifying aerobody
    Action Items
    • Email Andy to get detailed information on possible contacts for composite materials, equipment, and possible paint sponsor
    • Schedule "demo" to possibly construction practice panels at Composite Creation's facilities

    Action items

    •