Dekaplex used to be sold by Aladdins Cave, but in the days when I used it I wanted a different colour to the range on offer. I contacted Manders Paints who were the manufacturers and was informed that they did an industrial equivalent called Polarguard HB, which had the benefit of being a third of the price and available in a much wider range of colours.
I painted the plywood cockpit of a Gypsy sloop with Dekaplex in 1984, using three coats (with the corners reinforced by embedding surgical bandage). Fourteen years later I went on board the same boat again and inspected the job. Much to my amazement no extra coats had been added, the wear was minimal and there was no sign of the paint cracking. Incredible stuff.
Now I want to paint out the cockpit of our recently acquired 1965 Wanderer, which has a plywood cockpit built from not the finest grade of ply. I'm hoping that if Dekaplex can repeat its wonders the cockpit will last at least another 14 years.
I'll see if I can track down Polarguard HB, and I'll see if I can avoid the all encompasing, all dominating, slightly expensive Aladdins Cave.