The answer: Depends. 

 

The construction techniques available in 1989 and utilized before Fast Builds, before Cap Strips, before Hysol were thus:

 

Usually double-joggled joints were closed with a two-part 3M industrial grade structural adhesive (called 3M hereafter) that had several noteworthy properties.  It was fuel-proof.  Thinner was better in that the adhesion betwixt parts was stronger than the goop itself, thus squeeze out was important. 

 

A. Joggled joints had to be clamped to accomplish proper squeeze out and pop rivets were useful for this function.  Two bid were used in the exterior joggle depression and, where possible, a single bid on the interior after flox (epoxy/flox combo) was applied to smooth the overlap.  Note that each stage required more sanding and prep.

 

B. Non-structural parts (i.e. elevator pushrod tunnel) were microed in and supported with one or two bid applied over the joined surfaces and one inch on either side of the joint.  The bid was best applied before the micro cured.

 

C. Bulkheads utilized flox for the joint along with two (or more) bid as in B. It was soon learned that the bid was best applied whilst the flox was still wet thus eliminating more sand-fill-sand stages.

 

D. Ribs and spars in all flying surfaces were installed to the first-side skins like bulkheads (see C).

 

E. Closing out major pieces (i.e. wings) was accomplished by:

a. Carefully fitting the close out piece.

b. With the receiving rib/spar filled with flox and the skin covered with release tape, the parts were fitted and clamped.

c. After cure, the parts separated, the flox area cleaned and sanded, 3M smeared on both sides and the parts clamped together.

 

F. Control surface final skins were attached soley with flox.

 

Thus, for example, my lower wing skin (holding up the fuel bays) are held at the ribs by a mere half-inch of 3M.  Thus, the use of "depends" during high G maneuvers.

 

The invention of cap strips (rib/bulkhead flanges) changed everything.  More modern fast build techniques have ribs and bulkheads pre built of glass (no foam or nomex cores) with 1 to 1.5 inch flanges. Initial surface attachments can be made with flox only (no additional bid) because of the large joint surface.  Skin close-outs are done with Hysol (similar to 3M) and no special fitting procedure, perhaps because it is a better adhesive when thicker, perhaps because some flox fibers are mixed in with it, perhaps because it doesn't exotherm or some combination of these.  The newer epoxy, with its' quick cure time and tendency to exotherm, is a benefit for faster construction but cannot be made in large quantities. The addition of bid is done at certain close out joints for proper strength.

 

Any Lancair project should be judged by whether the construction methods appropriate at the time Lancair produced the kit (or later modified the directions/components) were actually followed by the builder. I don't know of any structural failures in Lancairs thusly built.