I'm curious as to what people expect or get for resin uptake when infusing with a foam core. I did a small test panel and it seemed a bit heavy. I don't have the numbers handy but I was heavier than I had hoped for. my panels are single skin so any uptake has a big impact.

The stack was 200gsm plain weave, 5mm 80kg/m3 Airex C70.75 perforated, 200gsm biax, peel ply, release film, flow media.

The little pump I have now doesn't get a super deep vacuum, it topped out at around 120mb absolute but the bag was good and only dropped 3mb in 15min. Afterwards I did a test with a single skin of each of the reinforcements and the skins came out with a reasonable resin ratio

From the testing I've done with various cores, I'd expect a perforated foam core to be somewhere around 400 grams per square metre per mm thickness. 

Yeah, weighing it again today and using the numbers from my single skin tests puts it around 400g/m2 for the core. I would imagine that you could get that weight down by making skins then bonding them to the core but that is quite a bit more work. I also imagine that the infused in one go gives you better general properties.

Yeh personally I'm not a huge fan of the grooved and scored foam cores, they do end up quite heavy. Depending on the application, 3D PET core can be better because it only uses about 300g/m2/mm. I prefer it for relatively thin applications. Once you start getting to like 10-15mm core thickness then I wouldn't use 3D PET core in any stressful application as it will shear from itself, so that is where the PVC cores come into their own.