Hello, my name is Greg Bakker and this page shows some of the process of the construction of my own personal aircraft, the Varieze (very easy). Designed by Burt Rutan in the early seventies, the Varieze is a high performance two seat aircraft designed for high speed efficient cross country travel.
The construction process is known as moldless sandwich composite construction and at the time it was developed, became the state of the art, spawning a renaissance in aircraft design and construction, often referred to as The Rutan Revolution.
This is the fuselage (upside down) shaped on the outside, ready for glassing. The green foam is rigid polyurethane, shaped using standard woodworking tools. The tan coloured bulkheads are made from high density (16lbs/cubic foot) PVC foam.
Composite construction
The picture on the left shows my brother Paul and me laying up the fibreglass plies on the fuselage bulkheads.
You can see peel ply strips across the centre of the bulkhead, these dacron strips smooth out the transition when one ply terminates over another. That's my Dad in the background, he often comes along to offer valuable free advice!
This is me, wetting out the fibreglass which will become the hard, structural outer shell of the fuselage. The fuselage is supported on a central pivot type arrangement so that it can be rotated and laminated on all sides.
Above is the fuselage assembled and all fibreglass plies completed. The headrest structure has also been added. The stainless steel firewall is being trial fitted. The green centre section spar that will support the wings is in the background. The picture on the right shows Kyle and Hannah clowning it up after completion of the main wing layups and the installation of the metal wing fittings. They are weighted into place until the epoxy cures (the wing fittings, not the kids.)
Hopefully, my aircraft will look something like this someday. This is an Austalian built Varieze photographed at the Sport Aircraft Association Annual Convention at Mangalore. That's Kyle wondering how many more photos dad is going to take.
Simply put, this style of construction uses fibreglass laminated with an epoxy laminating system, layed up over rigid foam cores that can be shaped or formed with ease.
The foam core is the first stage of the construction process. Several different types of foam are used in an aircraft such as the Varieze.
Styrofoam FB is used in the wings and flying surfaces and is shaped and cut using a hotwire saw.
Polyurethane is used in the fuselage, fuel tanks and centre section spar and is shaped using a knife, wire brush and sandpaper. It is fuel proof and very easy to carve.
PVC foam is used in other areas where a durable, light weight part is required. PVC can be cut and shaped using standard wood working tools, it is also heat formable.
To over simplify the process, the cores for each part are formed from the required foam type, density etc. any internal fibreglass structural facings are then included and the entire part covered in several plies or layers of fibreglass. The two types fibreglass cloth used in the Varieze are a special weave and weight for the hand lay-up techniques used. They are known as Rutan 7725 Bidirectional and 7715 Unidirectional.
