During the latter years of the war, specially glued plywoods were developed, primarily for use in aircraft and marine craft production. Owing to the weight factor it was very eagerly sought by the caravan builders as a material which would withstand severe usage, not deteriorate in the weather, and possess enough strength to withstand caravanning conditions.
These merits it certainly has, but there are certain pitfalls for the unwary, inasmuch that some of the first marine ply caravans deteriorated very quickly and were failures. This was caused by incorrect painting methods. Experience has proved that special considerations should be given to the prime coats and most satisfactory results are achieved by the following method: