Glue type

Hi,
The norm for the really accurate World War 1 replicas is that a combination of glues are used, to my knowledge casein was used only recently on a static replica.
For longerons and spars and their scarf joints the formaledehide glue (for example Aerodux) is used, typically of very dark colour, but the scrafs are then machined further, so there is not really much evidence of the darker glue used. Using some skill and if the joint is not overly complex, then even Aerodux can be made rather unobvious. See below. The nose bowl of the Albatros for example is a complex piece!
Usually the glue used for other joints is the expoxy glue (and not the laminating type) which gives the same appearance as per original, however it is much less complicated to aplly then casein. However the final decision on the glue used also depends on what type of wood is used as adherecence varies with the type of wood also.
For the replica projects that I know the only true concesion is to use a bit of an advanced varnished on the bottom skins of engine compartments to aid in cleaning the oils.
Kindest regards,
Saso

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