this is on a 355 rebody, planning to fill the hollows with expanding foam.

My main question, is if you put too much foam in and it tries to continue expanding does it actually exert force and potentially alter the panel shape ? ( i presume you could minimise this by providing a number of relief / vent holes )

Or does the foam just become denser if it cant 'move' as it expands ?

For anyone thats done their car with this , any drawbacks or comments on foam filling ?, would you recomend doing it ? ie no reactions with the grp resin etc ?

thanks, nick