I'm aware of three construction methods for fiberglass trailers currently in use ... there may be others:
Aluminum framed and bonded with a roller or pinched together with mechanical pressure ... this method is effective but if pressure isn't applied uniformly there is a potential risk of a weak bond in a section of the wall leading to delamination or bubbling
Aluminum framed and vacuum bonded where the bonding is done by placing the wall in a bag, pulling a vacuum, and atmospheric pressure pushes uniformly on the wall sections. The belief is that the more uniform pressure from vacuum bonding leads to full bonding of the wall and minimizes future delamination.
The above two methods use foam insulation (think styrofoam cup) as the center section of the walls.
A full studded aluminum frame with fiberglass batt insulation. The walls are then glued with adhesives to the frame. This method is used by Cedar Creek and a very similar method was used by Cross Roads ... although I believe Cross Roads is moving to a laminated wall construction (I believe using a roll bonding process).
There are other methods ... at one time Holiday Rambler I believe mechanically fastened there wall board to the frame ... if you look closely at these trailers you will see a line of rivets mid-way up the walls. I believe that Holiday Rambler trailers now use conventional bonded wall construction.
To the best of my knowledge filon is a brand of wall panel manufactured by Crane Composites and not a wall construction method.
