Hello All,

The pictures at this thread beginning do not show shearing strength because there is a moment arm.
The weight is not at the glued joint but a short distance away.

In most model construction the resistance to shearing is not the main concern.
The main concern is the ability of the joint to hold and any break to occur in the structure and not at the joint.

We are not really concerned with the pieces used in this test as illustrated.
We are concerned wth the integrity of the whole structure ( frame ) of the model in an abnormal landing.

The structure and finish is the main concern regardless of the glue ( cement , adhesive ) used.
A finish that provides strength and reduce forces at the joint is the way to go. Such is provided by a fabric finish where the fabic is fastened ( glued ) to all the structure of the model.

Another factor of importance is the area and shape of any glued joint. Filleting all joints to increase the binding area is highly beneficial. Many joints can have five ( 5 ) times the gluing area by filleting. The glue weight increase is absolutely negligeable versus the total weight of a model.

Penetration of the gluing adhesive into the two parts being joined is of secondary importance since the breakage will simply occur just beyond the degree of penetration.

Of course the design of a model structure enters into play.
A model can be designed aiming at replacement ( a new sale ) for the slighest improper landing or the structure can be designed for minimum damage in a high speed nose-in into the ground.

It will be interesting to see the results of the tests initiated earlier in this thread.
I think that the strength of the adhesive ( glue ) is not the main factor in crash-proofing a model airplane.

Just my feelings based on my experience. There is no doubt that some objections to this posting will occur.

Still it will be nice to see the tests being made with other types of adhesive.

Zor