+x+xIf this is wet lay vacuum bagging then 23inhg is generally too much vacuum so could have made things worse by squeezing out more resin. Generally we tend to recommend around 6-7 inHg as a starting point only varying it to suit results. Also 60/40 is a fairly idealistic fibre resin ratio. Typically you would expect around 50/50 for wet lay up maybe a bit better with experience and tweaking the vacuum levels to suit results.
Certainly resin uptake of the core is worth considering here as well.
Interesting comment. Years ago I asked an Airtech support person some questions on vacuum bagging. He suggested pulling a full vacuum and after a short 'period of time' backing off to 10hg to let the fabric expand some. I honestly cannot remember what the length of time was. A little off topic. I have also seen many posts where people say the resin needs to fill
'a
ll the voids'. I thought the only place the resin needed to be was as a coating around each fiber.
I'm not discounting what you are saying, just have never seen 6-7 hg as a starting point stated before.
Alan
Are you sure you have this the right way round? I remember seeing an Airtech research paper on the vacuum bagging process, and in that paper they were talking about taking advantage of the resin viscosity curve to get full compaction. They did it opposite to what you have said here though, they started off at 10hg and then as the resin viscosity increased as it started to gel they increased the vacuum until they were eventually at full vacuum just prior to the resin going to B-stage.
The theory was to use the low initial vacuum to extract the air and squeeze a bit of excess resin out, and then by following the viscosity curve they could achieve full consolidation on the fibres without bleeding too much resin or getting excessive voids due to expansion at full vac.
The paper claimed resin infusion-like results with void content of less then 1%, which is impressive for wet-lay. Will see if I can find that study again.