You raise an interesting point with the PET core vs the Soric there with regards to resin uptake, Warren. I have tested the 2 of those before, and I found a negligible difference between the PET and the Soric, both 3mm. Both consumed roughly 550 grams per square meter per millimetre thickness. Which I found very interesting given the PET cores larger cell structure and smaller channels. My supplier has found the same thing. 

I'm floored (pun intended) to hear that 2-3mm cork underlayment is a substantial core material. Is it appropriate for use with poly resin?

The proper stuff is compatible with all resin systems so I can't see why the floor board stuff wouldn't be. 

Also, on the thought of preparing the core for infusion, the Amorim stuff I have doesn't appear to be 'prepared' in anyway. It looks like your regular run of the mill cork board. No obvious holes or scoring. Just the random 'channels' that normal cork has. 

Let's not praise cork too much, it might be nice and cheap but it has a pretty high density. The fact that parts made with soric aren't any lighter doesn't make cork great, it just shows what a shitty choice materials that soak up resin like soric are for thick parts. Compared to other core materials (like rohacell, airex, polyurethanes, balsa, styrofoams etc. and of course honeycombs) the cork sandwiches are very heavy.

Perhaps, but you're missing the point. For an infusion application, cork performs and it performs well. My praise was specifically in comparison to other infusion specific bulker mats like Soric and PET core. And of course you can use other non-infusion specific cores, but for me the cork has other benefits that make it worthwhile even if it is a little bit heavier. 

I have a customer who manufactures wind turbines. In the layup schedule for the blades he specifies Soric. I would love to hear what you would suggest he should be using?
Requirements:  Conforms easily to compound curves.
                         Withstands high crush forces (hard points)
                         Acts as an excellent flow medium.
                         Easy to work with and requiring no special tools
                         Comparable on price.

Then I can tell him what he should be using instead of the "shitty" Soric he currently specifies in his award winning design.
 
Thanks in advance Warren.

Carbon Copies Ltd

> I have a customer who manufactures wind turbines. In the layup schedule for the blades he specifies Soric. I would love to hear what
> you would suggest he should be using?

Whatever it takes to perform the job. If Soric works for him, and it obviously does, fine, then there's nothing wrong with it. (Wind turbine blades don't need to be extremely lightweight if I remember correctly)

For many applications where weight doesn't matter all that much bulking materials like Soric or Coremat which soak up a lot of resin are perfectly acceptable and are a great improvement over using a full laminate to achieve the same strength.

While "shitty" might have been a little strong, I was merely trying to point out the not-so-stellar weight and density properties of cork and Soric in the final laminate, and reminding people that there are other options. There have been a few comments here and in other threads of people wanting to use cork with carbon. This is perfectly ok, do whatever you want. I do remember the carbon shortages a few years ago though, and using carbon (which used to be quite pricey and sometimes hard to get) with materials originally introduced to the polyester industry still bothers me a little. In the past when something was made of carbon this implied very light and very strong, so I still tend to advise people to use lightweight core materials. The additional costs didn't matter much in the past, but obviously they do now since carbon has become cheaper, and visible carbon is in high demand

Cork does have a few benefits, like its vibration dampening properties, it's just heavy (relatively speaking) compared to many other core materials.

Thanks for the feedback everyone,