Troubles with infusion and Divinycell core

First, thanks for providing so much info on this forum. I have gone thru several similar topics here including:
http://www.compositescentral.com/showthread.php?t=7327
but I’m still struggling to get a successful (complete) infusion with the foam core and hope for some pointers…

My first attempt at infusion was successful. A 12"x 12" test square of the following (bottom to top): (picture 1)

  • Glass plate
  • wax/PVA
  • 3 layers 2x2 twill 6K 11oz/sq yard.
  • nylon peel ply
  • perforated release film
  • flow media
  • vacuum bag
    single 3/8" inlet one edge, surrounded by MTI hose on 3 sides.
    20mbar vacuum with degassed 900 cps (fiberglast 2000) epoxy.
    Part came out perfect! No pin holes and fully wetted out. :slight_smile:

2nd attempt is similar (3 layers CF, core, 3 layers CF) with 1/4" foam core that I perforated 1/16" holes every 2" and then grid scored across on both top and bottom sides (at holes) and beveled edges at 45 degrees AND reduced MTI hose to one side in an attempt to simulate the intended final part and I also added the Enka sleeve/channel as seen in picture 2. The top was completely wet, but the result on bottom can be seen in picture 3 (racetrack???).

My last attempt was nearly identical, but with 650 cps (pt&m 2725) degassed epoxy, I extended the cloth overlap beyond the core as seen in picture 4 and eliminated the flow media on top of the stack and put the MTI hose in a pleat of peel ply. This time the infusion stalled as seen in picture 4 at which point I opened the bag and put in some breather/cloth in a desperate attempt to get the resin to flow.

Any idea what I may be doing wrong here? It seems like the stack is too compressed to allow flow and I may need a thinner epoxy??? My only requirement is that I have to maintain the overall thickness of the 3 layer, core, 3 layer for this part.

Thanks in advance!!!