Hi guys,

First of all, I want to say sorry that I use imperial measurements not metric...

I have some .125" (approx 3.1mm) pvc closed foam that I want to use a core in trunk lid mold.  This may be the same as the 5mm EC advertises.  It is not perforated and I am wondering if need to perforate it myself before it is usedin a vacuum bagging application.  I do not understand how the excess resin will be removed if it is not. Is this a valid concern, or can I vacuum bag or infuse without added work (use as is)? 

I have also have heard of people pressing chicken wire into the pvc to help with infusion.  Is this valid?

Hi,

You've posted this question in the Easy Composites technical area which is really reserved for people using our products or planning to use our products. The general forum is recommended for none Easy Composites products or peer-to-peer advice.

Anyway, in answer to your question, you could certainly vacuum bag the closed cell foam without any perforation; if you did this you would probably find that some of the excess resin would be squeezed out of the sides of the laminate and some would remain inside it but as this is a 'mould' you're making and not the part itself it wouldn't really matter if there was some excess resin in there. If it's not the mould you're making and it is the part itself then it would be worthwhile perforating the foam as this would help to allow excess resin to be removed from the part.

I've not heard of pressing chicken wire into foam, if you want to infuse your laminate (rather than vacuum bag it) then you'll need LOTS of perforation through the foam (1.5mm to 2mm holes and 10mm centres) to facilitate the resin flow from the top skin to the bottom skin. Simply pressing mesh into the foam won't have any effect if the resin can't get from the top skin to the bottom.

I hope this helps.

--Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Hi,

Generally speaking it is better to make the foam core panel as you mould the sheets as the resin will fill the open cells on the outside fully getting a better bond.

For normal vacuum bagging, you have to work the foam carefully to ensure you don't get any air entrapment under the foam.  Some light score lines can help.

With resin infusion we recommend our pre-scored and drilled foam as it allows a path for the resin to flow evenly to the bottom laminate layer.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant